exp2 (problem 3.3.7)

Percentage Accurate: 54.2% → 100.0%
Time: 14.1s
Alternatives: 13
Speedup: 2.0×

Specification

?
\[\left|x\right| \leq 710\]
\[\begin{array}{l} \\ \left(e^{x} - 2\right) + e^{-x} \end{array} \]
(FPCore (x) :precision binary64 (+ (- (exp x) 2.0) (exp (- x))))
double code(double x) {
	return (exp(x) - 2.0) + exp(-x);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (exp(x) - 2.0d0) + exp(-x)
end function
public static double code(double x) {
	return (Math.exp(x) - 2.0) + Math.exp(-x);
}
def code(x):
	return (math.exp(x) - 2.0) + math.exp(-x)
function code(x)
	return Float64(Float64(exp(x) - 2.0) + exp(Float64(-x)))
end
function tmp = code(x)
	tmp = (exp(x) - 2.0) + exp(-x);
end
code[x_] := N[(N[(N[Exp[x], $MachinePrecision] - 2.0), $MachinePrecision] + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(e^{x} - 2\right) + e^{-x}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 13 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 54.2% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(e^{x} - 2\right) + e^{-x} \end{array} \]
(FPCore (x) :precision binary64 (+ (- (exp x) 2.0) (exp (- x))))
double code(double x) {
	return (exp(x) - 2.0) + exp(-x);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (exp(x) - 2.0d0) + exp(-x)
end function
public static double code(double x) {
	return (Math.exp(x) - 2.0) + Math.exp(-x);
}
def code(x):
	return (math.exp(x) - 2.0) + math.exp(-x)
function code(x)
	return Float64(Float64(exp(x) - 2.0) + exp(Float64(-x)))
end
function tmp = code(x)
	tmp = (exp(x) - 2.0) + exp(-x);
end
code[x_] := N[(N[(N[Exp[x], $MachinePrecision] - 2.0), $MachinePrecision] + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(e^{x} - 2\right) + e^{-x}
\end{array}

Alternative 1: 100.0% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := e^{-x}\\ \mathbf{if}\;\left(e^{x} - 2\right) + t\_0 \leq 0.01:\\ \;\;\;\;{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot \left(0.002777777777777778 + {x}^{2} \cdot 4.96031746031746 \cdot 10^{-5}\right)\right)\right)\\ \mathbf{else}:\\ \;\;\;\;e^{\log \left(t\_0 + \left(-1 + \mathsf{expm1}\left(x\right)\right)\right)}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (exp (- x))))
   (if (<= (+ (- (exp x) 2.0) t_0) 0.01)
     (*
      (pow x 2.0)
      (+
       1.0
       (*
        (pow x 2.0)
        (+
         0.08333333333333333
         (*
          (pow x 2.0)
          (+ 0.002777777777777778 (* (pow x 2.0) 4.96031746031746e-5)))))))
     (exp (log (+ t_0 (+ -1.0 (expm1 x))))))))
double code(double x) {
	double t_0 = exp(-x);
	double tmp;
	if (((exp(x) - 2.0) + t_0) <= 0.01) {
		tmp = pow(x, 2.0) * (1.0 + (pow(x, 2.0) * (0.08333333333333333 + (pow(x, 2.0) * (0.002777777777777778 + (pow(x, 2.0) * 4.96031746031746e-5))))));
	} else {
		tmp = exp(log((t_0 + (-1.0 + expm1(x)))));
	}
	return tmp;
}
public static double code(double x) {
	double t_0 = Math.exp(-x);
	double tmp;
	if (((Math.exp(x) - 2.0) + t_0) <= 0.01) {
		tmp = Math.pow(x, 2.0) * (1.0 + (Math.pow(x, 2.0) * (0.08333333333333333 + (Math.pow(x, 2.0) * (0.002777777777777778 + (Math.pow(x, 2.0) * 4.96031746031746e-5))))));
	} else {
		tmp = Math.exp(Math.log((t_0 + (-1.0 + Math.expm1(x)))));
	}
	return tmp;
}
def code(x):
	t_0 = math.exp(-x)
	tmp = 0
	if ((math.exp(x) - 2.0) + t_0) <= 0.01:
		tmp = math.pow(x, 2.0) * (1.0 + (math.pow(x, 2.0) * (0.08333333333333333 + (math.pow(x, 2.0) * (0.002777777777777778 + (math.pow(x, 2.0) * 4.96031746031746e-5))))))
	else:
		tmp = math.exp(math.log((t_0 + (-1.0 + math.expm1(x)))))
	return tmp
function code(x)
	t_0 = exp(Float64(-x))
	tmp = 0.0
	if (Float64(Float64(exp(x) - 2.0) + t_0) <= 0.01)
		tmp = Float64((x ^ 2.0) * Float64(1.0 + Float64((x ^ 2.0) * Float64(0.08333333333333333 + Float64((x ^ 2.0) * Float64(0.002777777777777778 + Float64((x ^ 2.0) * 4.96031746031746e-5)))))));
	else
		tmp = exp(log(Float64(t_0 + Float64(-1.0 + expm1(x)))));
	end
	return tmp
end
code[x_] := Block[{t$95$0 = N[Exp[(-x)], $MachinePrecision]}, If[LessEqual[N[(N[(N[Exp[x], $MachinePrecision] - 2.0), $MachinePrecision] + t$95$0), $MachinePrecision], 0.01], N[(N[Power[x, 2.0], $MachinePrecision] * N[(1.0 + N[(N[Power[x, 2.0], $MachinePrecision] * N[(0.08333333333333333 + N[(N[Power[x, 2.0], $MachinePrecision] * N[(0.002777777777777778 + N[(N[Power[x, 2.0], $MachinePrecision] * 4.96031746031746e-5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[Exp[N[Log[N[(t$95$0 + N[(-1.0 + N[(Exp[x] - 1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := e^{-x}\\
\mathbf{if}\;\left(e^{x} - 2\right) + t\_0 \leq 0.01:\\
\;\;\;\;{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot \left(0.002777777777777778 + {x}^{2} \cdot 4.96031746031746 \cdot 10^{-5}\right)\right)\right)\\

\mathbf{else}:\\
\;\;\;\;e^{\log \left(t\_0 + \left(-1 + \mathsf{expm1}\left(x\right)\right)\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (-.f64 (exp.f64 x) #s(literal 2 binary64)) (exp.f64 (neg.f64 x))) < 0.0100000000000000002

    1. Initial program 56.0%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. associate-+l-56.0%

        \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
      2. sub-neg56.0%

        \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
      3. sub-neg56.0%

        \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
      4. distribute-neg-in56.0%

        \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
      5. remove-double-neg56.0%

        \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
      6. +-commutative56.0%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      7. metadata-eval56.0%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified56.0%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 100.0%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot \left(0.002777777777777778 + 4.96031746031746 \cdot 10^{-5} \cdot {x}^{2}\right)\right)\right)} \]
    6. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto {x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot \left(0.002777777777777778 + \color{blue}{{x}^{2} \cdot 4.96031746031746 \cdot 10^{-5}}\right)\right)\right) \]
    7. Simplified100.0%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot \left(0.002777777777777778 + {x}^{2} \cdot 4.96031746031746 \cdot 10^{-5}\right)\right)\right)} \]

    if 0.0100000000000000002 < (+.f64 (-.f64 (exp.f64 x) #s(literal 2 binary64)) (exp.f64 (neg.f64 x)))

    1. Initial program 98.4%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. associate-+l-98.2%

        \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
      2. sub-neg98.2%

        \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
      3. sub-neg98.2%

        \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
      4. distribute-neg-in98.2%

        \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
      5. remove-double-neg98.2%

        \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
      6. +-commutative98.2%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      7. metadata-eval98.2%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified98.2%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. +-commutative98.2%

        \[\leadsto e^{x} + \color{blue}{\left(-2 + e^{-x}\right)} \]
      2. associate-+r+98.4%

        \[\leadsto \color{blue}{\left(e^{x} + -2\right) + e^{-x}} \]
      3. metadata-eval98.4%

        \[\leadsto \left(e^{x} + \color{blue}{\left(-2\right)}\right) + e^{-x} \]
      4. sub-neg98.4%

        \[\leadsto \color{blue}{\left(e^{x} - 2\right)} + e^{-x} \]
      5. add-exp-log97.2%

        \[\leadsto \color{blue}{e^{\log \left(\left(e^{x} - 2\right) + e^{-x}\right)}} \]
      6. +-commutative97.2%

        \[\leadsto e^{\log \color{blue}{\left(e^{-x} + \left(e^{x} - 2\right)\right)}} \]
      7. sub-neg97.2%

        \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\left(e^{x} + \left(-2\right)\right)}\right)} \]
      8. metadata-eval97.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(e^{x} + \color{blue}{-2}\right)\right)} \]
      9. associate-+r+97.0%

        \[\leadsto e^{\log \color{blue}{\left(\left(e^{-x} + e^{x}\right) + -2\right)}} \]
      10. +-commutative97.0%

        \[\leadsto e^{\log \left(\color{blue}{\left(e^{x} + e^{-x}\right)} + -2\right)} \]
      11. +-commutative97.0%

        \[\leadsto e^{\log \color{blue}{\left(-2 + \left(e^{x} + e^{-x}\right)\right)}} \]
      12. cosh-undef97.0%

        \[\leadsto e^{\log \left(-2 + \color{blue}{2 \cdot \cosh x}\right)} \]
    6. Applied egg-rr97.0%

      \[\leadsto \color{blue}{e^{\log \left(-2 + 2 \cdot \cosh x\right)}} \]
    7. Taylor expanded in x around inf 97.0%

      \[\leadsto e^{\color{blue}{\log \left(\left(e^{x} + \frac{1}{e^{x}}\right) - 2\right)}} \]
    8. Step-by-step derivation
      1. sub-neg97.0%

        \[\leadsto e^{\log \color{blue}{\left(\left(e^{x} + \frac{1}{e^{x}}\right) + \left(-2\right)\right)}} \]
      2. +-commutative97.0%

        \[\leadsto e^{\log \left(\color{blue}{\left(\frac{1}{e^{x}} + e^{x}\right)} + \left(-2\right)\right)} \]
      3. metadata-eval97.0%

        \[\leadsto e^{\log \left(\left(\frac{1}{e^{x}} + e^{x}\right) + \color{blue}{-2}\right)} \]
      4. associate-+l+98.8%

        \[\leadsto e^{\log \color{blue}{\left(\frac{1}{e^{x}} + \left(e^{x} + -2\right)\right)}} \]
      5. rec-exp97.2%

        \[\leadsto e^{\log \left(\color{blue}{e^{-x}} + \left(e^{x} + -2\right)\right)} \]
    9. Simplified97.2%

      \[\leadsto e^{\color{blue}{\log \left(e^{-x} + \left(e^{x} + -2\right)\right)}} \]
    10. Step-by-step derivation
      1. expm1-log1p-u48.4%

        \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(e^{x} + -2\right)\right)}\right)} \]
      2. expm1-undefine48.4%

        \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\left(e^{\mathsf{log1p}\left(e^{x} + -2\right)} - 1\right)}\right)} \]
    11. Applied egg-rr48.4%

      \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\left(e^{\mathsf{log1p}\left(e^{x} + -2\right)} - 1\right)}\right)} \]
    12. Step-by-step derivation
      1. sub-neg48.4%

        \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\left(e^{\mathsf{log1p}\left(e^{x} + -2\right)} + \left(-1\right)\right)}\right)} \]
      2. log1p-undefine48.4%

        \[\leadsto e^{\log \left(e^{-x} + \left(e^{\color{blue}{\log \left(1 + \left(e^{x} + -2\right)\right)}} + \left(-1\right)\right)\right)} \]
      3. rem-exp-log97.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(\color{blue}{\left(1 + \left(e^{x} + -2\right)\right)} + \left(-1\right)\right)\right)} \]
      4. +-commutative97.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(\left(1 + \color{blue}{\left(-2 + e^{x}\right)}\right) + \left(-1\right)\right)\right)} \]
      5. associate-+r+97.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(\color{blue}{\left(\left(1 + -2\right) + e^{x}\right)} + \left(-1\right)\right)\right)} \]
      6. metadata-eval97.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(\left(\color{blue}{-1} + e^{x}\right) + \left(-1\right)\right)\right)} \]
      7. +-commutative97.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(\color{blue}{\left(e^{x} + -1\right)} + \left(-1\right)\right)\right)} \]
      8. metadata-eval97.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(\left(e^{x} + -1\right) + \color{blue}{-1}\right)\right)} \]
      9. +-commutative97.2%

        \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\left(-1 + \left(e^{x} + -1\right)\right)}\right)} \]
      10. metadata-eval97.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(-1 + \left(e^{x} + \color{blue}{\left(-1\right)}\right)\right)\right)} \]
      11. sub-neg97.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(-1 + \color{blue}{\left(e^{x} - 1\right)}\right)\right)} \]
      12. expm1-define98.8%

        \[\leadsto e^{\log \left(e^{-x} + \left(-1 + \color{blue}{\mathsf{expm1}\left(x\right)}\right)\right)} \]
    13. Simplified98.8%

      \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\left(-1 + \mathsf{expm1}\left(x\right)\right)}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(e^{x} - 2\right) + e^{-x} \leq 0.01:\\ \;\;\;\;{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot \left(0.002777777777777778 + {x}^{2} \cdot 4.96031746031746 \cdot 10^{-5}\right)\right)\right)\\ \mathbf{else}:\\ \;\;\;\;e^{\log \left(e^{-x} + \left(-1 + \mathsf{expm1}\left(x\right)\right)\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 99.9% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := e^{-x}\\ \mathbf{if}\;\left(e^{x} - 2\right) + t\_0 \leq 0.0005:\\ \;\;\;\;{x}^{2} + {x}^{4} \cdot \mathsf{fma}\left(0.002777777777777778, {x}^{2}, 0.08333333333333333\right)\\ \mathbf{else}:\\ \;\;\;\;e^{\log \left(t\_0 + \left(-1 + \mathsf{expm1}\left(x\right)\right)\right)}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (exp (- x))))
   (if (<= (+ (- (exp x) 2.0) t_0) 0.0005)
     (+
      (pow x 2.0)
      (*
       (pow x 4.0)
       (fma 0.002777777777777778 (pow x 2.0) 0.08333333333333333)))
     (exp (log (+ t_0 (+ -1.0 (expm1 x))))))))
double code(double x) {
	double t_0 = exp(-x);
	double tmp;
	if (((exp(x) - 2.0) + t_0) <= 0.0005) {
		tmp = pow(x, 2.0) + (pow(x, 4.0) * fma(0.002777777777777778, pow(x, 2.0), 0.08333333333333333));
	} else {
		tmp = exp(log((t_0 + (-1.0 + expm1(x)))));
	}
	return tmp;
}
function code(x)
	t_0 = exp(Float64(-x))
	tmp = 0.0
	if (Float64(Float64(exp(x) - 2.0) + t_0) <= 0.0005)
		tmp = Float64((x ^ 2.0) + Float64((x ^ 4.0) * fma(0.002777777777777778, (x ^ 2.0), 0.08333333333333333)));
	else
		tmp = exp(log(Float64(t_0 + Float64(-1.0 + expm1(x)))));
	end
	return tmp
end
code[x_] := Block[{t$95$0 = N[Exp[(-x)], $MachinePrecision]}, If[LessEqual[N[(N[(N[Exp[x], $MachinePrecision] - 2.0), $MachinePrecision] + t$95$0), $MachinePrecision], 0.0005], N[(N[Power[x, 2.0], $MachinePrecision] + N[(N[Power[x, 4.0], $MachinePrecision] * N[(0.002777777777777778 * N[Power[x, 2.0], $MachinePrecision] + 0.08333333333333333), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[Exp[N[Log[N[(t$95$0 + N[(-1.0 + N[(Exp[x] - 1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := e^{-x}\\
\mathbf{if}\;\left(e^{x} - 2\right) + t\_0 \leq 0.0005:\\
\;\;\;\;{x}^{2} + {x}^{4} \cdot \mathsf{fma}\left(0.002777777777777778, {x}^{2}, 0.08333333333333333\right)\\

\mathbf{else}:\\
\;\;\;\;e^{\log \left(t\_0 + \left(-1 + \mathsf{expm1}\left(x\right)\right)\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (-.f64 (exp.f64 x) #s(literal 2 binary64)) (exp.f64 (neg.f64 x))) < 5.0000000000000001e-4

    1. Initial program 55.9%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. associate-+l-55.9%

        \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
      2. sub-neg55.9%

        \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
      3. sub-neg55.9%

        \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
      4. distribute-neg-in55.9%

        \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
      5. remove-double-neg55.9%

        \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
      6. +-commutative55.9%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      7. metadata-eval55.9%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified55.9%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 100.0%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot \left(0.002777777777777778 + 4.96031746031746 \cdot 10^{-5} \cdot {x}^{2}\right)\right)\right)} \]
    6. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto {x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot \left(0.002777777777777778 + \color{blue}{{x}^{2} \cdot 4.96031746031746 \cdot 10^{-5}}\right)\right)\right) \]
    7. Simplified100.0%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot \left(0.002777777777777778 + {x}^{2} \cdot 4.96031746031746 \cdot 10^{-5}\right)\right)\right)} \]
    8. Taylor expanded in x around 0 100.0%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + 0.002777777777777778 \cdot {x}^{2}\right)\right)} \]
    9. Step-by-step derivation
      1. distribute-lft-in100.0%

        \[\leadsto \color{blue}{{x}^{2} \cdot 1 + {x}^{2} \cdot \left({x}^{2} \cdot \left(0.08333333333333333 + 0.002777777777777778 \cdot {x}^{2}\right)\right)} \]
      2. *-rgt-identity100.0%

        \[\leadsto \color{blue}{{x}^{2}} + {x}^{2} \cdot \left({x}^{2} \cdot \left(0.08333333333333333 + 0.002777777777777778 \cdot {x}^{2}\right)\right) \]
      3. associate-*r*100.0%

        \[\leadsto {x}^{2} + \color{blue}{\left({x}^{2} \cdot {x}^{2}\right) \cdot \left(0.08333333333333333 + 0.002777777777777778 \cdot {x}^{2}\right)} \]
      4. pow-sqr100.0%

        \[\leadsto {x}^{2} + \color{blue}{{x}^{\left(2 \cdot 2\right)}} \cdot \left(0.08333333333333333 + 0.002777777777777778 \cdot {x}^{2}\right) \]
      5. metadata-eval100.0%

        \[\leadsto {x}^{2} + {x}^{\color{blue}{4}} \cdot \left(0.08333333333333333 + 0.002777777777777778 \cdot {x}^{2}\right) \]
      6. +-commutative100.0%

        \[\leadsto {x}^{2} + {x}^{4} \cdot \color{blue}{\left(0.002777777777777778 \cdot {x}^{2} + 0.08333333333333333\right)} \]
      7. fma-define100.0%

        \[\leadsto {x}^{2} + {x}^{4} \cdot \color{blue}{\mathsf{fma}\left(0.002777777777777778, {x}^{2}, 0.08333333333333333\right)} \]
    10. Simplified100.0%

      \[\leadsto \color{blue}{{x}^{2} + {x}^{4} \cdot \mathsf{fma}\left(0.002777777777777778, {x}^{2}, 0.08333333333333333\right)} \]

    if 5.0000000000000001e-4 < (+.f64 (-.f64 (exp.f64 x) #s(literal 2 binary64)) (exp.f64 (neg.f64 x)))

    1. Initial program 97.2%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. associate-+l-97.3%

        \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
      2. sub-neg97.3%

        \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
      3. sub-neg97.3%

        \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
      4. distribute-neg-in97.3%

        \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
      5. remove-double-neg97.3%

        \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
      6. +-commutative97.3%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      7. metadata-eval97.3%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified97.3%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. +-commutative97.3%

        \[\leadsto e^{x} + \color{blue}{\left(-2 + e^{-x}\right)} \]
      2. associate-+r+97.2%

        \[\leadsto \color{blue}{\left(e^{x} + -2\right) + e^{-x}} \]
      3. metadata-eval97.2%

        \[\leadsto \left(e^{x} + \color{blue}{\left(-2\right)}\right) + e^{-x} \]
      4. sub-neg97.2%

        \[\leadsto \color{blue}{\left(e^{x} - 2\right)} + e^{-x} \]
      5. add-exp-log96.2%

        \[\leadsto \color{blue}{e^{\log \left(\left(e^{x} - 2\right) + e^{-x}\right)}} \]
      6. +-commutative96.2%

        \[\leadsto e^{\log \color{blue}{\left(e^{-x} + \left(e^{x} - 2\right)\right)}} \]
      7. sub-neg96.2%

        \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\left(e^{x} + \left(-2\right)\right)}\right)} \]
      8. metadata-eval96.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(e^{x} + \color{blue}{-2}\right)\right)} \]
      9. associate-+r+95.7%

        \[\leadsto e^{\log \color{blue}{\left(\left(e^{-x} + e^{x}\right) + -2\right)}} \]
      10. +-commutative95.7%

        \[\leadsto e^{\log \left(\color{blue}{\left(e^{x} + e^{-x}\right)} + -2\right)} \]
      11. +-commutative95.7%

        \[\leadsto e^{\log \color{blue}{\left(-2 + \left(e^{x} + e^{-x}\right)\right)}} \]
      12. cosh-undef95.7%

        \[\leadsto e^{\log \left(-2 + \color{blue}{2 \cdot \cosh x}\right)} \]
    6. Applied egg-rr95.7%

      \[\leadsto \color{blue}{e^{\log \left(-2 + 2 \cdot \cosh x\right)}} \]
    7. Taylor expanded in x around inf 95.6%

      \[\leadsto e^{\color{blue}{\log \left(\left(e^{x} + \frac{1}{e^{x}}\right) - 2\right)}} \]
    8. Step-by-step derivation
      1. sub-neg95.6%

        \[\leadsto e^{\log \color{blue}{\left(\left(e^{x} + \frac{1}{e^{x}}\right) + \left(-2\right)\right)}} \]
      2. +-commutative95.6%

        \[\leadsto e^{\log \left(\color{blue}{\left(\frac{1}{e^{x}} + e^{x}\right)} + \left(-2\right)\right)} \]
      3. metadata-eval95.6%

        \[\leadsto e^{\log \left(\left(\frac{1}{e^{x}} + e^{x}\right) + \color{blue}{-2}\right)} \]
      4. associate-+l+97.8%

        \[\leadsto e^{\log \color{blue}{\left(\frac{1}{e^{x}} + \left(e^{x} + -2\right)\right)}} \]
      5. rec-exp96.2%

        \[\leadsto e^{\log \left(\color{blue}{e^{-x}} + \left(e^{x} + -2\right)\right)} \]
    9. Simplified96.2%

      \[\leadsto e^{\color{blue}{\log \left(e^{-x} + \left(e^{x} + -2\right)\right)}} \]
    10. Step-by-step derivation
      1. expm1-log1p-u54.4%

        \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(e^{x} + -2\right)\right)}\right)} \]
      2. expm1-undefine54.4%

        \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\left(e^{\mathsf{log1p}\left(e^{x} + -2\right)} - 1\right)}\right)} \]
    11. Applied egg-rr54.4%

      \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\left(e^{\mathsf{log1p}\left(e^{x} + -2\right)} - 1\right)}\right)} \]
    12. Step-by-step derivation
      1. sub-neg54.4%

        \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\left(e^{\mathsf{log1p}\left(e^{x} + -2\right)} + \left(-1\right)\right)}\right)} \]
      2. log1p-undefine54.4%

        \[\leadsto e^{\log \left(e^{-x} + \left(e^{\color{blue}{\log \left(1 + \left(e^{x} + -2\right)\right)}} + \left(-1\right)\right)\right)} \]
      3. rem-exp-log96.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(\color{blue}{\left(1 + \left(e^{x} + -2\right)\right)} + \left(-1\right)\right)\right)} \]
      4. +-commutative96.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(\left(1 + \color{blue}{\left(-2 + e^{x}\right)}\right) + \left(-1\right)\right)\right)} \]
      5. associate-+r+96.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(\color{blue}{\left(\left(1 + -2\right) + e^{x}\right)} + \left(-1\right)\right)\right)} \]
      6. metadata-eval96.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(\left(\color{blue}{-1} + e^{x}\right) + \left(-1\right)\right)\right)} \]
      7. +-commutative96.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(\color{blue}{\left(e^{x} + -1\right)} + \left(-1\right)\right)\right)} \]
      8. metadata-eval96.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(\left(e^{x} + -1\right) + \color{blue}{-1}\right)\right)} \]
      9. +-commutative96.2%

        \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\left(-1 + \left(e^{x} + -1\right)\right)}\right)} \]
      10. metadata-eval96.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(-1 + \left(e^{x} + \color{blue}{\left(-1\right)}\right)\right)\right)} \]
      11. sub-neg96.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(-1 + \color{blue}{\left(e^{x} - 1\right)}\right)\right)} \]
      12. expm1-define97.5%

        \[\leadsto e^{\log \left(e^{-x} + \left(-1 + \color{blue}{\mathsf{expm1}\left(x\right)}\right)\right)} \]
    13. Simplified97.5%

      \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\left(-1 + \mathsf{expm1}\left(x\right)\right)}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(e^{x} - 2\right) + e^{-x} \leq 0.0005:\\ \;\;\;\;{x}^{2} + {x}^{4} \cdot \mathsf{fma}\left(0.002777777777777778, {x}^{2}, 0.08333333333333333\right)\\ \mathbf{else}:\\ \;\;\;\;e^{\log \left(e^{-x} + \left(-1 + \mathsf{expm1}\left(x\right)\right)\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 99.9% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := e^{-x}\\ \mathbf{if}\;\left(e^{x} - 2\right) + t\_0 \leq 0.0005:\\ \;\;\;\;{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot 0.002777777777777778\right)\right)\\ \mathbf{else}:\\ \;\;\;\;e^{\log \left(t\_0 + \left(-1 + \mathsf{expm1}\left(x\right)\right)\right)}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (exp (- x))))
   (if (<= (+ (- (exp x) 2.0) t_0) 0.0005)
     (*
      (pow x 2.0)
      (+
       1.0
       (*
        (pow x 2.0)
        (+ 0.08333333333333333 (* (pow x 2.0) 0.002777777777777778)))))
     (exp (log (+ t_0 (+ -1.0 (expm1 x))))))))
double code(double x) {
	double t_0 = exp(-x);
	double tmp;
	if (((exp(x) - 2.0) + t_0) <= 0.0005) {
		tmp = pow(x, 2.0) * (1.0 + (pow(x, 2.0) * (0.08333333333333333 + (pow(x, 2.0) * 0.002777777777777778))));
	} else {
		tmp = exp(log((t_0 + (-1.0 + expm1(x)))));
	}
	return tmp;
}
public static double code(double x) {
	double t_0 = Math.exp(-x);
	double tmp;
	if (((Math.exp(x) - 2.0) + t_0) <= 0.0005) {
		tmp = Math.pow(x, 2.0) * (1.0 + (Math.pow(x, 2.0) * (0.08333333333333333 + (Math.pow(x, 2.0) * 0.002777777777777778))));
	} else {
		tmp = Math.exp(Math.log((t_0 + (-1.0 + Math.expm1(x)))));
	}
	return tmp;
}
def code(x):
	t_0 = math.exp(-x)
	tmp = 0
	if ((math.exp(x) - 2.0) + t_0) <= 0.0005:
		tmp = math.pow(x, 2.0) * (1.0 + (math.pow(x, 2.0) * (0.08333333333333333 + (math.pow(x, 2.0) * 0.002777777777777778))))
	else:
		tmp = math.exp(math.log((t_0 + (-1.0 + math.expm1(x)))))
	return tmp
function code(x)
	t_0 = exp(Float64(-x))
	tmp = 0.0
	if (Float64(Float64(exp(x) - 2.0) + t_0) <= 0.0005)
		tmp = Float64((x ^ 2.0) * Float64(1.0 + Float64((x ^ 2.0) * Float64(0.08333333333333333 + Float64((x ^ 2.0) * 0.002777777777777778)))));
	else
		tmp = exp(log(Float64(t_0 + Float64(-1.0 + expm1(x)))));
	end
	return tmp
end
code[x_] := Block[{t$95$0 = N[Exp[(-x)], $MachinePrecision]}, If[LessEqual[N[(N[(N[Exp[x], $MachinePrecision] - 2.0), $MachinePrecision] + t$95$0), $MachinePrecision], 0.0005], N[(N[Power[x, 2.0], $MachinePrecision] * N[(1.0 + N[(N[Power[x, 2.0], $MachinePrecision] * N[(0.08333333333333333 + N[(N[Power[x, 2.0], $MachinePrecision] * 0.002777777777777778), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[Exp[N[Log[N[(t$95$0 + N[(-1.0 + N[(Exp[x] - 1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := e^{-x}\\
\mathbf{if}\;\left(e^{x} - 2\right) + t\_0 \leq 0.0005:\\
\;\;\;\;{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot 0.002777777777777778\right)\right)\\

\mathbf{else}:\\
\;\;\;\;e^{\log \left(t\_0 + \left(-1 + \mathsf{expm1}\left(x\right)\right)\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (-.f64 (exp.f64 x) #s(literal 2 binary64)) (exp.f64 (neg.f64 x))) < 5.0000000000000001e-4

    1. Initial program 55.9%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. associate-+l-55.9%

        \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
      2. sub-neg55.9%

        \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
      3. sub-neg55.9%

        \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
      4. distribute-neg-in55.9%

        \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
      5. remove-double-neg55.9%

        \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
      6. +-commutative55.9%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      7. metadata-eval55.9%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified55.9%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 100.0%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + 0.002777777777777778 \cdot {x}^{2}\right)\right)} \]
    6. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto {x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + \color{blue}{{x}^{2} \cdot 0.002777777777777778}\right)\right) \]
    7. Simplified100.0%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot 0.002777777777777778\right)\right)} \]

    if 5.0000000000000001e-4 < (+.f64 (-.f64 (exp.f64 x) #s(literal 2 binary64)) (exp.f64 (neg.f64 x)))

    1. Initial program 97.2%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. associate-+l-97.3%

        \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
      2. sub-neg97.3%

        \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
      3. sub-neg97.3%

        \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
      4. distribute-neg-in97.3%

        \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
      5. remove-double-neg97.3%

        \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
      6. +-commutative97.3%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      7. metadata-eval97.3%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified97.3%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. +-commutative97.3%

        \[\leadsto e^{x} + \color{blue}{\left(-2 + e^{-x}\right)} \]
      2. associate-+r+97.2%

        \[\leadsto \color{blue}{\left(e^{x} + -2\right) + e^{-x}} \]
      3. metadata-eval97.2%

        \[\leadsto \left(e^{x} + \color{blue}{\left(-2\right)}\right) + e^{-x} \]
      4. sub-neg97.2%

        \[\leadsto \color{blue}{\left(e^{x} - 2\right)} + e^{-x} \]
      5. add-exp-log96.2%

        \[\leadsto \color{blue}{e^{\log \left(\left(e^{x} - 2\right) + e^{-x}\right)}} \]
      6. +-commutative96.2%

        \[\leadsto e^{\log \color{blue}{\left(e^{-x} + \left(e^{x} - 2\right)\right)}} \]
      7. sub-neg96.2%

        \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\left(e^{x} + \left(-2\right)\right)}\right)} \]
      8. metadata-eval96.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(e^{x} + \color{blue}{-2}\right)\right)} \]
      9. associate-+r+95.7%

        \[\leadsto e^{\log \color{blue}{\left(\left(e^{-x} + e^{x}\right) + -2\right)}} \]
      10. +-commutative95.7%

        \[\leadsto e^{\log \left(\color{blue}{\left(e^{x} + e^{-x}\right)} + -2\right)} \]
      11. +-commutative95.7%

        \[\leadsto e^{\log \color{blue}{\left(-2 + \left(e^{x} + e^{-x}\right)\right)}} \]
      12. cosh-undef95.7%

        \[\leadsto e^{\log \left(-2 + \color{blue}{2 \cdot \cosh x}\right)} \]
    6. Applied egg-rr95.7%

      \[\leadsto \color{blue}{e^{\log \left(-2 + 2 \cdot \cosh x\right)}} \]
    7. Taylor expanded in x around inf 95.6%

      \[\leadsto e^{\color{blue}{\log \left(\left(e^{x} + \frac{1}{e^{x}}\right) - 2\right)}} \]
    8. Step-by-step derivation
      1. sub-neg95.6%

        \[\leadsto e^{\log \color{blue}{\left(\left(e^{x} + \frac{1}{e^{x}}\right) + \left(-2\right)\right)}} \]
      2. +-commutative95.6%

        \[\leadsto e^{\log \left(\color{blue}{\left(\frac{1}{e^{x}} + e^{x}\right)} + \left(-2\right)\right)} \]
      3. metadata-eval95.6%

        \[\leadsto e^{\log \left(\left(\frac{1}{e^{x}} + e^{x}\right) + \color{blue}{-2}\right)} \]
      4. associate-+l+97.8%

        \[\leadsto e^{\log \color{blue}{\left(\frac{1}{e^{x}} + \left(e^{x} + -2\right)\right)}} \]
      5. rec-exp96.2%

        \[\leadsto e^{\log \left(\color{blue}{e^{-x}} + \left(e^{x} + -2\right)\right)} \]
    9. Simplified96.2%

      \[\leadsto e^{\color{blue}{\log \left(e^{-x} + \left(e^{x} + -2\right)\right)}} \]
    10. Step-by-step derivation
      1. expm1-log1p-u54.4%

        \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(e^{x} + -2\right)\right)}\right)} \]
      2. expm1-undefine54.4%

        \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\left(e^{\mathsf{log1p}\left(e^{x} + -2\right)} - 1\right)}\right)} \]
    11. Applied egg-rr54.4%

      \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\left(e^{\mathsf{log1p}\left(e^{x} + -2\right)} - 1\right)}\right)} \]
    12. Step-by-step derivation
      1. sub-neg54.4%

        \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\left(e^{\mathsf{log1p}\left(e^{x} + -2\right)} + \left(-1\right)\right)}\right)} \]
      2. log1p-undefine54.4%

        \[\leadsto e^{\log \left(e^{-x} + \left(e^{\color{blue}{\log \left(1 + \left(e^{x} + -2\right)\right)}} + \left(-1\right)\right)\right)} \]
      3. rem-exp-log96.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(\color{blue}{\left(1 + \left(e^{x} + -2\right)\right)} + \left(-1\right)\right)\right)} \]
      4. +-commutative96.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(\left(1 + \color{blue}{\left(-2 + e^{x}\right)}\right) + \left(-1\right)\right)\right)} \]
      5. associate-+r+96.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(\color{blue}{\left(\left(1 + -2\right) + e^{x}\right)} + \left(-1\right)\right)\right)} \]
      6. metadata-eval96.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(\left(\color{blue}{-1} + e^{x}\right) + \left(-1\right)\right)\right)} \]
      7. +-commutative96.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(\color{blue}{\left(e^{x} + -1\right)} + \left(-1\right)\right)\right)} \]
      8. metadata-eval96.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(\left(e^{x} + -1\right) + \color{blue}{-1}\right)\right)} \]
      9. +-commutative96.2%

        \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\left(-1 + \left(e^{x} + -1\right)\right)}\right)} \]
      10. metadata-eval96.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(-1 + \left(e^{x} + \color{blue}{\left(-1\right)}\right)\right)\right)} \]
      11. sub-neg96.2%

        \[\leadsto e^{\log \left(e^{-x} + \left(-1 + \color{blue}{\left(e^{x} - 1\right)}\right)\right)} \]
      12. expm1-define97.5%

        \[\leadsto e^{\log \left(e^{-x} + \left(-1 + \color{blue}{\mathsf{expm1}\left(x\right)}\right)\right)} \]
    13. Simplified97.5%

      \[\leadsto e^{\log \left(e^{-x} + \color{blue}{\left(-1 + \mathsf{expm1}\left(x\right)\right)}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(e^{x} - 2\right) + e^{-x} \leq 0.0005:\\ \;\;\;\;{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot 0.002777777777777778\right)\right)\\ \mathbf{else}:\\ \;\;\;\;e^{\log \left(e^{-x} + \left(-1 + \mathsf{expm1}\left(x\right)\right)\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 99.9% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := e^{-x}\\ \mathbf{if}\;\left(e^{x} - 2\right) + t\_0 \leq 0.0005:\\ \;\;\;\;{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot 0.002777777777777778\right)\right)\\ \mathbf{else}:\\ \;\;\;\;e^{x} + \left(t\_0 + -2\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (exp (- x))))
   (if (<= (+ (- (exp x) 2.0) t_0) 0.0005)
     (*
      (pow x 2.0)
      (+
       1.0
       (*
        (pow x 2.0)
        (+ 0.08333333333333333 (* (pow x 2.0) 0.002777777777777778)))))
     (+ (exp x) (+ t_0 -2.0)))))
double code(double x) {
	double t_0 = exp(-x);
	double tmp;
	if (((exp(x) - 2.0) + t_0) <= 0.0005) {
		tmp = pow(x, 2.0) * (1.0 + (pow(x, 2.0) * (0.08333333333333333 + (pow(x, 2.0) * 0.002777777777777778))));
	} else {
		tmp = exp(x) + (t_0 + -2.0);
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: tmp
    t_0 = exp(-x)
    if (((exp(x) - 2.0d0) + t_0) <= 0.0005d0) then
        tmp = (x ** 2.0d0) * (1.0d0 + ((x ** 2.0d0) * (0.08333333333333333d0 + ((x ** 2.0d0) * 0.002777777777777778d0))))
    else
        tmp = exp(x) + (t_0 + (-2.0d0))
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = Math.exp(-x);
	double tmp;
	if (((Math.exp(x) - 2.0) + t_0) <= 0.0005) {
		tmp = Math.pow(x, 2.0) * (1.0 + (Math.pow(x, 2.0) * (0.08333333333333333 + (Math.pow(x, 2.0) * 0.002777777777777778))));
	} else {
		tmp = Math.exp(x) + (t_0 + -2.0);
	}
	return tmp;
}
def code(x):
	t_0 = math.exp(-x)
	tmp = 0
	if ((math.exp(x) - 2.0) + t_0) <= 0.0005:
		tmp = math.pow(x, 2.0) * (1.0 + (math.pow(x, 2.0) * (0.08333333333333333 + (math.pow(x, 2.0) * 0.002777777777777778))))
	else:
		tmp = math.exp(x) + (t_0 + -2.0)
	return tmp
function code(x)
	t_0 = exp(Float64(-x))
	tmp = 0.0
	if (Float64(Float64(exp(x) - 2.0) + t_0) <= 0.0005)
		tmp = Float64((x ^ 2.0) * Float64(1.0 + Float64((x ^ 2.0) * Float64(0.08333333333333333 + Float64((x ^ 2.0) * 0.002777777777777778)))));
	else
		tmp = Float64(exp(x) + Float64(t_0 + -2.0));
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = exp(-x);
	tmp = 0.0;
	if (((exp(x) - 2.0) + t_0) <= 0.0005)
		tmp = (x ^ 2.0) * (1.0 + ((x ^ 2.0) * (0.08333333333333333 + ((x ^ 2.0) * 0.002777777777777778))));
	else
		tmp = exp(x) + (t_0 + -2.0);
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[Exp[(-x)], $MachinePrecision]}, If[LessEqual[N[(N[(N[Exp[x], $MachinePrecision] - 2.0), $MachinePrecision] + t$95$0), $MachinePrecision], 0.0005], N[(N[Power[x, 2.0], $MachinePrecision] * N[(1.0 + N[(N[Power[x, 2.0], $MachinePrecision] * N[(0.08333333333333333 + N[(N[Power[x, 2.0], $MachinePrecision] * 0.002777777777777778), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[Exp[x], $MachinePrecision] + N[(t$95$0 + -2.0), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := e^{-x}\\
\mathbf{if}\;\left(e^{x} - 2\right) + t\_0 \leq 0.0005:\\
\;\;\;\;{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot 0.002777777777777778\right)\right)\\

\mathbf{else}:\\
\;\;\;\;e^{x} + \left(t\_0 + -2\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (-.f64 (exp.f64 x) #s(literal 2 binary64)) (exp.f64 (neg.f64 x))) < 5.0000000000000001e-4

    1. Initial program 55.9%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. associate-+l-55.9%

        \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
      2. sub-neg55.9%

        \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
      3. sub-neg55.9%

        \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
      4. distribute-neg-in55.9%

        \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
      5. remove-double-neg55.9%

        \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
      6. +-commutative55.9%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      7. metadata-eval55.9%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified55.9%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 100.0%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + 0.002777777777777778 \cdot {x}^{2}\right)\right)} \]
    6. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto {x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + \color{blue}{{x}^{2} \cdot 0.002777777777777778}\right)\right) \]
    7. Simplified100.0%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot 0.002777777777777778\right)\right)} \]

    if 5.0000000000000001e-4 < (+.f64 (-.f64 (exp.f64 x) #s(literal 2 binary64)) (exp.f64 (neg.f64 x)))

    1. Initial program 97.2%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. associate-+l-97.3%

        \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
      2. sub-neg97.3%

        \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
      3. sub-neg97.3%

        \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
      4. distribute-neg-in97.3%

        \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
      5. remove-double-neg97.3%

        \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
      6. +-commutative97.3%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      7. metadata-eval97.3%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified97.3%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Add Preprocessing
  3. Recombined 2 regimes into one program.
  4. Final simplification99.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(e^{x} - 2\right) + e^{-x} \leq 0.0005:\\ \;\;\;\;{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot 0.002777777777777778\right)\right)\\ \mathbf{else}:\\ \;\;\;\;e^{x} + \left(e^{-x} + -2\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 99.6% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := e^{-x}\\ \mathbf{if}\;\left(e^{x} - 2\right) + t\_0 \leq 10^{-9}:\\ \;\;\;\;{x}^{2}\\ \mathbf{else}:\\ \;\;\;\;e^{x} + \left(t\_0 + -2\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (exp (- x))))
   (if (<= (+ (- (exp x) 2.0) t_0) 1e-9)
     (pow x 2.0)
     (+ (exp x) (+ t_0 -2.0)))))
double code(double x) {
	double t_0 = exp(-x);
	double tmp;
	if (((exp(x) - 2.0) + t_0) <= 1e-9) {
		tmp = pow(x, 2.0);
	} else {
		tmp = exp(x) + (t_0 + -2.0);
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: tmp
    t_0 = exp(-x)
    if (((exp(x) - 2.0d0) + t_0) <= 1d-9) then
        tmp = x ** 2.0d0
    else
        tmp = exp(x) + (t_0 + (-2.0d0))
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = Math.exp(-x);
	double tmp;
	if (((Math.exp(x) - 2.0) + t_0) <= 1e-9) {
		tmp = Math.pow(x, 2.0);
	} else {
		tmp = Math.exp(x) + (t_0 + -2.0);
	}
	return tmp;
}
def code(x):
	t_0 = math.exp(-x)
	tmp = 0
	if ((math.exp(x) - 2.0) + t_0) <= 1e-9:
		tmp = math.pow(x, 2.0)
	else:
		tmp = math.exp(x) + (t_0 + -2.0)
	return tmp
function code(x)
	t_0 = exp(Float64(-x))
	tmp = 0.0
	if (Float64(Float64(exp(x) - 2.0) + t_0) <= 1e-9)
		tmp = x ^ 2.0;
	else
		tmp = Float64(exp(x) + Float64(t_0 + -2.0));
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = exp(-x);
	tmp = 0.0;
	if (((exp(x) - 2.0) + t_0) <= 1e-9)
		tmp = x ^ 2.0;
	else
		tmp = exp(x) + (t_0 + -2.0);
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[Exp[(-x)], $MachinePrecision]}, If[LessEqual[N[(N[(N[Exp[x], $MachinePrecision] - 2.0), $MachinePrecision] + t$95$0), $MachinePrecision], 1e-9], N[Power[x, 2.0], $MachinePrecision], N[(N[Exp[x], $MachinePrecision] + N[(t$95$0 + -2.0), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := e^{-x}\\
\mathbf{if}\;\left(e^{x} - 2\right) + t\_0 \leq 10^{-9}:\\
\;\;\;\;{x}^{2}\\

\mathbf{else}:\\
\;\;\;\;e^{x} + \left(t\_0 + -2\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (-.f64 (exp.f64 x) #s(literal 2 binary64)) (exp.f64 (neg.f64 x))) < 1.00000000000000006e-9

    1. Initial program 55.7%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. associate-+l-55.7%

        \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
      2. sub-neg55.7%

        \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
      3. sub-neg55.7%

        \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
      4. distribute-neg-in55.7%

        \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
      5. remove-double-neg55.7%

        \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
      6. +-commutative55.7%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      7. metadata-eval55.7%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified55.7%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 99.8%

      \[\leadsto \color{blue}{{x}^{2}} \]

    if 1.00000000000000006e-9 < (+.f64 (-.f64 (exp.f64 x) #s(literal 2 binary64)) (exp.f64 (neg.f64 x)))

    1. Initial program 96.2%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. associate-+l-96.3%

        \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
      2. sub-neg96.3%

        \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
      3. sub-neg96.3%

        \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
      4. distribute-neg-in96.3%

        \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
      5. remove-double-neg96.3%

        \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
      6. +-commutative96.3%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      7. metadata-eval96.3%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified96.3%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Add Preprocessing
  3. Recombined 2 regimes into one program.
  4. Final simplification99.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(e^{x} - 2\right) + e^{-x} \leq 10^{-9}:\\ \;\;\;\;{x}^{2}\\ \mathbf{else}:\\ \;\;\;\;e^{x} + \left(e^{-x} + -2\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 99.8% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := e^{-x}\\ \mathbf{if}\;\left(e^{x} - 2\right) + t\_0 \leq 10^{-9}:\\ \;\;\;\;\mathsf{fma}\left(x, x, 0.08333333333333333 \cdot {x}^{4}\right)\\ \mathbf{else}:\\ \;\;\;\;e^{x} + \left(t\_0 + -2\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (exp (- x))))
   (if (<= (+ (- (exp x) 2.0) t_0) 1e-9)
     (fma x x (* 0.08333333333333333 (pow x 4.0)))
     (+ (exp x) (+ t_0 -2.0)))))
double code(double x) {
	double t_0 = exp(-x);
	double tmp;
	if (((exp(x) - 2.0) + t_0) <= 1e-9) {
		tmp = fma(x, x, (0.08333333333333333 * pow(x, 4.0)));
	} else {
		tmp = exp(x) + (t_0 + -2.0);
	}
	return tmp;
}
function code(x)
	t_0 = exp(Float64(-x))
	tmp = 0.0
	if (Float64(Float64(exp(x) - 2.0) + t_0) <= 1e-9)
		tmp = fma(x, x, Float64(0.08333333333333333 * (x ^ 4.0)));
	else
		tmp = Float64(exp(x) + Float64(t_0 + -2.0));
	end
	return tmp
end
code[x_] := Block[{t$95$0 = N[Exp[(-x)], $MachinePrecision]}, If[LessEqual[N[(N[(N[Exp[x], $MachinePrecision] - 2.0), $MachinePrecision] + t$95$0), $MachinePrecision], 1e-9], N[(x * x + N[(0.08333333333333333 * N[Power[x, 4.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[Exp[x], $MachinePrecision] + N[(t$95$0 + -2.0), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := e^{-x}\\
\mathbf{if}\;\left(e^{x} - 2\right) + t\_0 \leq 10^{-9}:\\
\;\;\;\;\mathsf{fma}\left(x, x, 0.08333333333333333 \cdot {x}^{4}\right)\\

\mathbf{else}:\\
\;\;\;\;e^{x} + \left(t\_0 + -2\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (-.f64 (exp.f64 x) #s(literal 2 binary64)) (exp.f64 (neg.f64 x))) < 1.00000000000000006e-9

    1. Initial program 55.7%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. associate-+l-55.7%

        \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
      2. sub-neg55.7%

        \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
      3. sub-neg55.7%

        \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
      4. distribute-neg-in55.7%

        \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
      5. remove-double-neg55.7%

        \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
      6. +-commutative55.7%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      7. metadata-eval55.7%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified55.7%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 100.0%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot \left(0.002777777777777778 + 4.96031746031746 \cdot 10^{-5} \cdot {x}^{2}\right)\right)\right)} \]
    6. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto {x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot \left(0.002777777777777778 + \color{blue}{{x}^{2} \cdot 4.96031746031746 \cdot 10^{-5}}\right)\right)\right) \]
    7. Simplified100.0%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot \left(0.002777777777777778 + {x}^{2} \cdot 4.96031746031746 \cdot 10^{-5}\right)\right)\right)} \]
    8. Taylor expanded in x around 0 100.0%

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(1 + 0.08333333333333333 \cdot {x}^{2}\right)} \]
    9. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto {x}^{2} \cdot \left(1 + \color{blue}{{x}^{2} \cdot 0.08333333333333333}\right) \]
      2. distribute-lft-in100.0%

        \[\leadsto \color{blue}{{x}^{2} \cdot 1 + {x}^{2} \cdot \left({x}^{2} \cdot 0.08333333333333333\right)} \]
      3. *-rgt-identity100.0%

        \[\leadsto \color{blue}{{x}^{2}} + {x}^{2} \cdot \left({x}^{2} \cdot 0.08333333333333333\right) \]
      4. associate-*r*100.0%

        \[\leadsto {x}^{2} + \color{blue}{\left({x}^{2} \cdot {x}^{2}\right) \cdot 0.08333333333333333} \]
      5. pow-sqr100.0%

        \[\leadsto {x}^{2} + \color{blue}{{x}^{\left(2 \cdot 2\right)}} \cdot 0.08333333333333333 \]
      6. metadata-eval100.0%

        \[\leadsto {x}^{2} + {x}^{\color{blue}{4}} \cdot 0.08333333333333333 \]
    10. Simplified100.0%

      \[\leadsto \color{blue}{{x}^{2} + {x}^{4} \cdot 0.08333333333333333} \]
    11. Step-by-step derivation
      1. unpow2100.0%

        \[\leadsto \color{blue}{x \cdot x} + {x}^{4} \cdot 0.08333333333333333 \]
      2. fma-define100.0%

        \[\leadsto \color{blue}{\mathsf{fma}\left(x, x, {x}^{4} \cdot 0.08333333333333333\right)} \]
    12. Applied egg-rr100.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x, x, {x}^{4} \cdot 0.08333333333333333\right)} \]

    if 1.00000000000000006e-9 < (+.f64 (-.f64 (exp.f64 x) #s(literal 2 binary64)) (exp.f64 (neg.f64 x)))

    1. Initial program 96.2%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. associate-+l-96.3%

        \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
      2. sub-neg96.3%

        \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
      3. sub-neg96.3%

        \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
      4. distribute-neg-in96.3%

        \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
      5. remove-double-neg96.3%

        \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
      6. +-commutative96.3%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      7. metadata-eval96.3%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified96.3%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Add Preprocessing
  3. Recombined 2 regimes into one program.
  4. Final simplification99.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(e^{x} - 2\right) + e^{-x} \leq 10^{-9}:\\ \;\;\;\;\mathsf{fma}\left(x, x, 0.08333333333333333 \cdot {x}^{4}\right)\\ \mathbf{else}:\\ \;\;\;\;e^{x} + \left(e^{-x} + -2\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 99.1% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 0.000116:\\ \;\;\;\;{x}^{2}\\ \mathbf{else}:\\ \;\;\;\;2 \cdot \cosh x - 2\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 0.000116) (pow x 2.0) (- (* 2.0 (cosh x)) 2.0)))
double code(double x) {
	double tmp;
	if (x <= 0.000116) {
		tmp = pow(x, 2.0);
	} else {
		tmp = (2.0 * cosh(x)) - 2.0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 0.000116d0) then
        tmp = x ** 2.0d0
    else
        tmp = (2.0d0 * cosh(x)) - 2.0d0
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 0.000116) {
		tmp = Math.pow(x, 2.0);
	} else {
		tmp = (2.0 * Math.cosh(x)) - 2.0;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 0.000116:
		tmp = math.pow(x, 2.0)
	else:
		tmp = (2.0 * math.cosh(x)) - 2.0
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 0.000116)
		tmp = x ^ 2.0;
	else
		tmp = Float64(Float64(2.0 * cosh(x)) - 2.0);
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 0.000116)
		tmp = x ^ 2.0;
	else
		tmp = (2.0 * cosh(x)) - 2.0;
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 0.000116], N[Power[x, 2.0], $MachinePrecision], N[(N[(2.0 * N[Cosh[x], $MachinePrecision]), $MachinePrecision] - 2.0), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 0.000116:\\
\;\;\;\;{x}^{2}\\

\mathbf{else}:\\
\;\;\;\;2 \cdot \cosh x - 2\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.16e-4

    1. Initial program 56.3%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. associate-+l-56.3%

        \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
      2. sub-neg56.3%

        \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
      3. sub-neg56.3%

        \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
      4. distribute-neg-in56.3%

        \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
      5. remove-double-neg56.3%

        \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
      6. +-commutative56.3%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      7. metadata-eval56.3%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified56.3%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 98.8%

      \[\leadsto \color{blue}{{x}^{2}} \]

    if 1.16e-4 < x

    1. Initial program 93.9%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. associate-+l-94.0%

        \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
      2. sub-neg94.0%

        \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
      3. sub-neg94.0%

        \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
      4. distribute-neg-in94.0%

        \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
      5. remove-double-neg94.0%

        \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
      6. +-commutative94.0%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      7. metadata-eval94.0%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified94.0%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. +-commutative94.0%

        \[\leadsto e^{x} + \color{blue}{\left(-2 + e^{-x}\right)} \]
      2. associate-+r+93.9%

        \[\leadsto \color{blue}{\left(e^{x} + -2\right) + e^{-x}} \]
      3. metadata-eval93.9%

        \[\leadsto \left(e^{x} + \color{blue}{\left(-2\right)}\right) + e^{-x} \]
      4. sub-neg93.9%

        \[\leadsto \color{blue}{\left(e^{x} - 2\right)} + e^{-x} \]
      5. +-commutative93.9%

        \[\leadsto \color{blue}{e^{-x} + \left(e^{x} - 2\right)} \]
      6. associate-+r-93.2%

        \[\leadsto \color{blue}{\left(e^{-x} + e^{x}\right) - 2} \]
      7. +-commutative93.2%

        \[\leadsto \color{blue}{\left(e^{x} + e^{-x}\right)} - 2 \]
      8. cosh-undef93.3%

        \[\leadsto \color{blue}{2 \cdot \cosh x} - 2 \]
    6. Applied egg-rr93.3%

      \[\leadsto \color{blue}{2 \cdot \cosh x - 2} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 0.000116:\\ \;\;\;\;{x}^{2}\\ \mathbf{else}:\\ \;\;\;\;2 \cdot \cosh x - 2\\ \end{array} \]
  5. Add Preprocessing

Alternative 8: 98.5% accurate, 2.0× speedup?

\[\begin{array}{l} \\ {x}^{2} \end{array} \]
(FPCore (x) :precision binary64 (pow x 2.0))
double code(double x) {
	return pow(x, 2.0);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = x ** 2.0d0
end function
public static double code(double x) {
	return Math.pow(x, 2.0);
}
def code(x):
	return math.pow(x, 2.0)
function code(x)
	return x ^ 2.0
end
function tmp = code(x)
	tmp = x ^ 2.0;
end
code[x_] := N[Power[x, 2.0], $MachinePrecision]
\begin{array}{l}

\\
{x}^{2}
\end{array}
Derivation
  1. Initial program 57.0%

    \[\left(e^{x} - 2\right) + e^{-x} \]
  2. Step-by-step derivation
    1. associate-+l-57.0%

      \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
    2. sub-neg57.0%

      \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
    3. sub-neg57.0%

      \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
    4. distribute-neg-in57.0%

      \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
    5. remove-double-neg57.0%

      \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
    6. +-commutative57.0%

      \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
    7. metadata-eval57.0%

      \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
  3. Simplified57.0%

    \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 97.3%

    \[\leadsto \color{blue}{{x}^{2}} \]
  6. Final simplification97.3%

    \[\leadsto {x}^{2} \]
  7. Add Preprocessing

Alternative 9: 6.1% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \mathsf{expm1}\left(x\right) \end{array} \]
(FPCore (x) :precision binary64 (expm1 x))
double code(double x) {
	return expm1(x);
}
public static double code(double x) {
	return Math.expm1(x);
}
def code(x):
	return math.expm1(x)
function code(x)
	return expm1(x)
end
code[x_] := N[(Exp[x] - 1), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{expm1}\left(x\right)
\end{array}
Derivation
  1. Initial program 57.0%

    \[\left(e^{x} - 2\right) + e^{-x} \]
  2. Step-by-step derivation
    1. associate-+l-57.0%

      \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
    2. sub-neg57.0%

      \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
    3. sub-neg57.0%

      \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
    4. distribute-neg-in57.0%

      \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
    5. remove-double-neg57.0%

      \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
    6. +-commutative57.0%

      \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
    7. metadata-eval57.0%

      \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
  3. Simplified57.0%

    \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 54.6%

    \[\leadsto e^{x} + \color{blue}{-1} \]
  6. Taylor expanded in x around inf 54.6%

    \[\leadsto \color{blue}{e^{x} - 1} \]
  7. Step-by-step derivation
    1. expm1-define6.8%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(x\right)} \]
  8. Simplified6.8%

    \[\leadsto \color{blue}{\mathsf{expm1}\left(x\right)} \]
  9. Final simplification6.8%

    \[\leadsto \mathsf{expm1}\left(x\right) \]
  10. Add Preprocessing

Alternative 10: 6.0% accurate, 13.7× speedup?

\[\begin{array}{l} \\ x \cdot \left(1 + x \cdot \left(0.5 + x \cdot \left(0.16666666666666666 + x \cdot 0.041666666666666664\right)\right)\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (*
  x
  (+
   1.0
   (* x (+ 0.5 (* x (+ 0.16666666666666666 (* x 0.041666666666666664))))))))
double code(double x) {
	return x * (1.0 + (x * (0.5 + (x * (0.16666666666666666 + (x * 0.041666666666666664))))));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = x * (1.0d0 + (x * (0.5d0 + (x * (0.16666666666666666d0 + (x * 0.041666666666666664d0))))))
end function
public static double code(double x) {
	return x * (1.0 + (x * (0.5 + (x * (0.16666666666666666 + (x * 0.041666666666666664))))));
}
def code(x):
	return x * (1.0 + (x * (0.5 + (x * (0.16666666666666666 + (x * 0.041666666666666664))))))
function code(x)
	return Float64(x * Float64(1.0 + Float64(x * Float64(0.5 + Float64(x * Float64(0.16666666666666666 + Float64(x * 0.041666666666666664)))))))
end
function tmp = code(x)
	tmp = x * (1.0 + (x * (0.5 + (x * (0.16666666666666666 + (x * 0.041666666666666664))))));
end
code[x_] := N[(x * N[(1.0 + N[(x * N[(0.5 + N[(x * N[(0.16666666666666666 + N[(x * 0.041666666666666664), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x \cdot \left(1 + x \cdot \left(0.5 + x \cdot \left(0.16666666666666666 + x \cdot 0.041666666666666664\right)\right)\right)
\end{array}
Derivation
  1. Initial program 57.0%

    \[\left(e^{x} - 2\right) + e^{-x} \]
  2. Step-by-step derivation
    1. associate-+l-57.0%

      \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
    2. sub-neg57.0%

      \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
    3. sub-neg57.0%

      \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
    4. distribute-neg-in57.0%

      \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
    5. remove-double-neg57.0%

      \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
    6. +-commutative57.0%

      \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
    7. metadata-eval57.0%

      \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
  3. Simplified57.0%

    \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 54.6%

    \[\leadsto e^{x} + \color{blue}{-1} \]
  6. Taylor expanded in x around 0 6.2%

    \[\leadsto \color{blue}{x \cdot \left(1 + x \cdot \left(0.5 + x \cdot \left(0.16666666666666666 + 0.041666666666666664 \cdot x\right)\right)\right)} \]
  7. Step-by-step derivation
    1. *-commutative6.2%

      \[\leadsto x \cdot \left(1 + x \cdot \left(0.5 + x \cdot \left(0.16666666666666666 + \color{blue}{x \cdot 0.041666666666666664}\right)\right)\right) \]
  8. Simplified6.2%

    \[\leadsto \color{blue}{x \cdot \left(1 + x \cdot \left(0.5 + x \cdot \left(0.16666666666666666 + x \cdot 0.041666666666666664\right)\right)\right)} \]
  9. Final simplification6.2%

    \[\leadsto x \cdot \left(1 + x \cdot \left(0.5 + x \cdot \left(0.16666666666666666 + x \cdot 0.041666666666666664\right)\right)\right) \]
  10. Add Preprocessing

Alternative 11: 5.9% accurate, 18.7× speedup?

\[\begin{array}{l} \\ x \cdot \left(1 + x \cdot \left(0.5 + x \cdot 0.16666666666666666\right)\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (* x (+ 1.0 (* x (+ 0.5 (* x 0.16666666666666666))))))
double code(double x) {
	return x * (1.0 + (x * (0.5 + (x * 0.16666666666666666))));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = x * (1.0d0 + (x * (0.5d0 + (x * 0.16666666666666666d0))))
end function
public static double code(double x) {
	return x * (1.0 + (x * (0.5 + (x * 0.16666666666666666))));
}
def code(x):
	return x * (1.0 + (x * (0.5 + (x * 0.16666666666666666))))
function code(x)
	return Float64(x * Float64(1.0 + Float64(x * Float64(0.5 + Float64(x * 0.16666666666666666)))))
end
function tmp = code(x)
	tmp = x * (1.0 + (x * (0.5 + (x * 0.16666666666666666))));
end
code[x_] := N[(x * N[(1.0 + N[(x * N[(0.5 + N[(x * 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x \cdot \left(1 + x \cdot \left(0.5 + x \cdot 0.16666666666666666\right)\right)
\end{array}
Derivation
  1. Initial program 57.0%

    \[\left(e^{x} - 2\right) + e^{-x} \]
  2. Step-by-step derivation
    1. associate-+l-57.0%

      \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
    2. sub-neg57.0%

      \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
    3. sub-neg57.0%

      \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
    4. distribute-neg-in57.0%

      \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
    5. remove-double-neg57.0%

      \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
    6. +-commutative57.0%

      \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
    7. metadata-eval57.0%

      \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
  3. Simplified57.0%

    \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 54.6%

    \[\leadsto e^{x} + \color{blue}{-1} \]
  6. Taylor expanded in x around 0 6.1%

    \[\leadsto \color{blue}{x \cdot \left(1 + x \cdot \left(0.5 + 0.16666666666666666 \cdot x\right)\right)} \]
  7. Step-by-step derivation
    1. *-commutative6.1%

      \[\leadsto x \cdot \left(1 + x \cdot \left(0.5 + \color{blue}{x \cdot 0.16666666666666666}\right)\right) \]
  8. Simplified6.1%

    \[\leadsto \color{blue}{x \cdot \left(1 + x \cdot \left(0.5 + x \cdot 0.16666666666666666\right)\right)} \]
  9. Final simplification6.1%

    \[\leadsto x \cdot \left(1 + x \cdot \left(0.5 + x \cdot 0.16666666666666666\right)\right) \]
  10. Add Preprocessing

Alternative 12: 5.9% accurate, 29.4× speedup?

\[\begin{array}{l} \\ x \cdot \left(1 + x \cdot 0.5\right) \end{array} \]
(FPCore (x) :precision binary64 (* x (+ 1.0 (* x 0.5))))
double code(double x) {
	return x * (1.0 + (x * 0.5));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = x * (1.0d0 + (x * 0.5d0))
end function
public static double code(double x) {
	return x * (1.0 + (x * 0.5));
}
def code(x):
	return x * (1.0 + (x * 0.5))
function code(x)
	return Float64(x * Float64(1.0 + Float64(x * 0.5)))
end
function tmp = code(x)
	tmp = x * (1.0 + (x * 0.5));
end
code[x_] := N[(x * N[(1.0 + N[(x * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x \cdot \left(1 + x \cdot 0.5\right)
\end{array}
Derivation
  1. Initial program 57.0%

    \[\left(e^{x} - 2\right) + e^{-x} \]
  2. Step-by-step derivation
    1. associate-+l-57.0%

      \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
    2. sub-neg57.0%

      \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
    3. sub-neg57.0%

      \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
    4. distribute-neg-in57.0%

      \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
    5. remove-double-neg57.0%

      \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
    6. +-commutative57.0%

      \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
    7. metadata-eval57.0%

      \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
  3. Simplified57.0%

    \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 54.6%

    \[\leadsto e^{x} + \color{blue}{-1} \]
  6. Taylor expanded in x around 0 6.2%

    \[\leadsto \color{blue}{x \cdot \left(1 + 0.5 \cdot x\right)} \]
  7. Step-by-step derivation
    1. *-commutative6.2%

      \[\leadsto x \cdot \left(1 + \color{blue}{x \cdot 0.5}\right) \]
  8. Simplified6.2%

    \[\leadsto \color{blue}{x \cdot \left(1 + x \cdot 0.5\right)} \]
  9. Final simplification6.2%

    \[\leadsto x \cdot \left(1 + x \cdot 0.5\right) \]
  10. Add Preprocessing

Alternative 13: 5.9% accurate, 206.0× speedup?

\[\begin{array}{l} \\ x \end{array} \]
(FPCore (x) :precision binary64 x)
double code(double x) {
	return x;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = x
end function
public static double code(double x) {
	return x;
}
def code(x):
	return x
function code(x)
	return x
end
function tmp = code(x)
	tmp = x;
end
code[x_] := x
\begin{array}{l}

\\
x
\end{array}
Derivation
  1. Initial program 57.0%

    \[\left(e^{x} - 2\right) + e^{-x} \]
  2. Step-by-step derivation
    1. associate-+l-57.0%

      \[\leadsto \color{blue}{e^{x} - \left(2 - e^{-x}\right)} \]
    2. sub-neg57.0%

      \[\leadsto \color{blue}{e^{x} + \left(-\left(2 - e^{-x}\right)\right)} \]
    3. sub-neg57.0%

      \[\leadsto e^{x} + \left(-\color{blue}{\left(2 + \left(-e^{-x}\right)\right)}\right) \]
    4. distribute-neg-in57.0%

      \[\leadsto e^{x} + \color{blue}{\left(\left(-2\right) + \left(-\left(-e^{-x}\right)\right)\right)} \]
    5. remove-double-neg57.0%

      \[\leadsto e^{x} + \left(\left(-2\right) + \color{blue}{e^{-x}}\right) \]
    6. +-commutative57.0%

      \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
    7. metadata-eval57.0%

      \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
  3. Simplified57.0%

    \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 54.6%

    \[\leadsto e^{x} + \color{blue}{-1} \]
  6. Taylor expanded in x around 0 6.1%

    \[\leadsto \color{blue}{x} \]
  7. Final simplification6.1%

    \[\leadsto x \]
  8. Add Preprocessing

Developer target: 99.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sinh \left(\frac{x}{2}\right)\\ 4 \cdot \left(t\_0 \cdot t\_0\right) \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (sinh (/ x 2.0)))) (* 4.0 (* t_0 t_0))))
double code(double x) {
	double t_0 = sinh((x / 2.0));
	return 4.0 * (t_0 * t_0);
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    t_0 = sinh((x / 2.0d0))
    code = 4.0d0 * (t_0 * t_0)
end function
public static double code(double x) {
	double t_0 = Math.sinh((x / 2.0));
	return 4.0 * (t_0 * t_0);
}
def code(x):
	t_0 = math.sinh((x / 2.0))
	return 4.0 * (t_0 * t_0)
function code(x)
	t_0 = sinh(Float64(x / 2.0))
	return Float64(4.0 * Float64(t_0 * t_0))
end
function tmp = code(x)
	t_0 = sinh((x / 2.0));
	tmp = 4.0 * (t_0 * t_0);
end
code[x_] := Block[{t$95$0 = N[Sinh[N[(x / 2.0), $MachinePrecision]], $MachinePrecision]}, N[(4.0 * N[(t$95$0 * t$95$0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sinh \left(\frac{x}{2}\right)\\
4 \cdot \left(t\_0 \cdot t\_0\right)
\end{array}
\end{array}

Reproduce

?
herbie shell --seed 2024066 
(FPCore (x)
  :name "exp2 (problem 3.3.7)"
  :precision binary64
  :pre (<= (fabs x) 710.0)

  :alt
  (* 4.0 (* (sinh (/ x 2.0)) (sinh (/ x 2.0))))

  (+ (- (exp x) 2.0) (exp (- x))))