Hyperbolic secant

Percentage Accurate: 100.0% → 100.0%
Time: 7.9s
Alternatives: 10
Speedup: 2.0×

Specification

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

\\
\frac{2}{e^{x} + 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 10 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: 100.0% accurate, 1.0× speedup?

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

\\
\frac{2}{e^{x} + e^{-x}}
\end{array}

Alternative 1: 100.0% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \frac{1}{\cosh x} \end{array} \]
(FPCore (x) :precision binary64 (/ 1.0 (cosh x)))
double code(double x) {
	return 1.0 / cosh(x);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 1.0d0 / cosh(x)
end function
public static double code(double x) {
	return 1.0 / Math.cosh(x);
}
def code(x):
	return 1.0 / math.cosh(x)
function code(x)
	return Float64(1.0 / cosh(x))
end
function tmp = code(x)
	tmp = 1.0 / cosh(x);
end
code[x_] := N[(1.0 / N[Cosh[x], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{\cosh x}
\end{array}
Derivation
  1. Initial program 100.0%

    \[\frac{2}{e^{x} + e^{-x}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. clear-numN/A

      \[\leadsto \frac{1}{\color{blue}{\frac{e^{x} + e^{\mathsf{neg}\left(x\right)}}{2}}} \]
    2. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \color{blue}{\left(\frac{e^{x} + e^{\mathsf{neg}\left(x\right)}}{2}\right)}\right) \]
    3. cosh-defN/A

      \[\leadsto \mathsf{/.f64}\left(1, \cosh x\right) \]
    4. cosh-lowering-cosh.f64100.0%

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{cosh.f64}\left(x\right)\right) \]
  4. Applied egg-rr100.0%

    \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
  5. Add Preprocessing

Alternative 2: 92.1% accurate, 9.8× speedup?

\[\begin{array}{l} \\ \frac{1}{1 + \left(x \cdot x\right) \cdot \left(0.5 + \left(x \cdot x\right) \cdot \left(0.041666666666666664 + \left(x \cdot x\right) \cdot 0.001388888888888889\right)\right)} \end{array} \]
(FPCore (x)
 :precision binary64
 (/
  1.0
  (+
   1.0
   (*
    (* x x)
    (+
     0.5
     (* (* x x) (+ 0.041666666666666664 (* (* x x) 0.001388888888888889))))))))
double code(double x) {
	return 1.0 / (1.0 + ((x * x) * (0.5 + ((x * x) * (0.041666666666666664 + ((x * x) * 0.001388888888888889))))));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 1.0d0 / (1.0d0 + ((x * x) * (0.5d0 + ((x * x) * (0.041666666666666664d0 + ((x * x) * 0.001388888888888889d0))))))
end function
public static double code(double x) {
	return 1.0 / (1.0 + ((x * x) * (0.5 + ((x * x) * (0.041666666666666664 + ((x * x) * 0.001388888888888889))))));
}
def code(x):
	return 1.0 / (1.0 + ((x * x) * (0.5 + ((x * x) * (0.041666666666666664 + ((x * x) * 0.001388888888888889))))))
function code(x)
	return Float64(1.0 / Float64(1.0 + Float64(Float64(x * x) * Float64(0.5 + Float64(Float64(x * x) * Float64(0.041666666666666664 + Float64(Float64(x * x) * 0.001388888888888889)))))))
end
function tmp = code(x)
	tmp = 1.0 / (1.0 + ((x * x) * (0.5 + ((x * x) * (0.041666666666666664 + ((x * x) * 0.001388888888888889))))));
end
code[x_] := N[(1.0 / N[(1.0 + N[(N[(x * x), $MachinePrecision] * N[(0.5 + N[(N[(x * x), $MachinePrecision] * N[(0.041666666666666664 + N[(N[(x * x), $MachinePrecision] * 0.001388888888888889), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{1 + \left(x \cdot x\right) \cdot \left(0.5 + \left(x \cdot x\right) \cdot \left(0.041666666666666664 + \left(x \cdot x\right) \cdot 0.001388888888888889\right)\right)}
\end{array}
Derivation
  1. Initial program 100.0%

    \[\frac{2}{e^{x} + e^{-x}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. clear-numN/A

      \[\leadsto \frac{1}{\color{blue}{\frac{e^{x} + e^{\mathsf{neg}\left(x\right)}}{2}}} \]
    2. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \color{blue}{\left(\frac{e^{x} + e^{\mathsf{neg}\left(x\right)}}{2}\right)}\right) \]
    3. cosh-defN/A

      \[\leadsto \mathsf{/.f64}\left(1, \cosh x\right) \]
    4. cosh-lowering-cosh.f64100.0%

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{cosh.f64}\left(x\right)\right) \]
  4. Applied egg-rr100.0%

    \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
  5. Taylor expanded in x around 0

    \[\leadsto \mathsf{/.f64}\left(1, \color{blue}{\left(1 + {x}^{2} \cdot \left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)\right)}\right) \]
  6. Step-by-step derivation
    1. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \color{blue}{\left({x}^{2} \cdot \left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)\right)}\right)\right) \]
    2. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)}\right)\right)\right) \]
    3. unpow2N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\left(x \cdot x\right), \left(\color{blue}{\frac{1}{2}} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)\right)\right)\right) \]
    4. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\color{blue}{\frac{1}{2}} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)\right)\right)\right) \]
    5. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \color{blue}{\left({x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)}\right)\right)\right)\right) \]
    6. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right) \]
    7. unpow2N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left(x \cdot x\right), \left(\color{blue}{\frac{1}{24}} + \frac{1}{720} \cdot {x}^{2}\right)\right)\right)\right)\right)\right) \]
    8. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\color{blue}{\frac{1}{24}} + \frac{1}{720} \cdot {x}^{2}\right)\right)\right)\right)\right)\right) \]
    9. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{24}, \color{blue}{\left(\frac{1}{720} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right)\right) \]
    10. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{24}, \left({x}^{2} \cdot \color{blue}{\frac{1}{720}}\right)\right)\right)\right)\right)\right)\right) \]
    11. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{24}, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\frac{1}{720}}\right)\right)\right)\right)\right)\right)\right) \]
    12. unpow2N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{24}, \mathsf{*.f64}\left(\left(x \cdot x\right), \frac{1}{720}\right)\right)\right)\right)\right)\right)\right) \]
    13. *-lowering-*.f6493.4%

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{24}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \frac{1}{720}\right)\right)\right)\right)\right)\right)\right) \]
  7. Simplified93.4%

    \[\leadsto \frac{1}{\color{blue}{1 + \left(x \cdot x\right) \cdot \left(0.5 + \left(x \cdot x\right) \cdot \left(0.041666666666666664 + \left(x \cdot x\right) \cdot 0.001388888888888889\right)\right)}} \]
  8. Add Preprocessing

Alternative 3: 91.9% accurate, 10.8× speedup?

\[\begin{array}{l} \\ \frac{1}{1 + \left(x \cdot x\right) \cdot \left(0.5 + 0.001388888888888889 \cdot \left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right)\right)} \end{array} \]
(FPCore (x)
 :precision binary64
 (/
  1.0
  (+ 1.0 (* (* x x) (+ 0.5 (* 0.001388888888888889 (* x (* x (* x x)))))))))
double code(double x) {
	return 1.0 / (1.0 + ((x * x) * (0.5 + (0.001388888888888889 * (x * (x * (x * x)))))));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 1.0d0 / (1.0d0 + ((x * x) * (0.5d0 + (0.001388888888888889d0 * (x * (x * (x * x)))))))
end function
public static double code(double x) {
	return 1.0 / (1.0 + ((x * x) * (0.5 + (0.001388888888888889 * (x * (x * (x * x)))))));
}
def code(x):
	return 1.0 / (1.0 + ((x * x) * (0.5 + (0.001388888888888889 * (x * (x * (x * x)))))))
function code(x)
	return Float64(1.0 / Float64(1.0 + Float64(Float64(x * x) * Float64(0.5 + Float64(0.001388888888888889 * Float64(x * Float64(x * Float64(x * x))))))))
end
function tmp = code(x)
	tmp = 1.0 / (1.0 + ((x * x) * (0.5 + (0.001388888888888889 * (x * (x * (x * x)))))));
end
code[x_] := N[(1.0 / N[(1.0 + N[(N[(x * x), $MachinePrecision] * N[(0.5 + N[(0.001388888888888889 * N[(x * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{1 + \left(x \cdot x\right) \cdot \left(0.5 + 0.001388888888888889 \cdot \left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right)\right)}
\end{array}
Derivation
  1. Initial program 100.0%

    \[\frac{2}{e^{x} + e^{-x}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. clear-numN/A

      \[\leadsto \frac{1}{\color{blue}{\frac{e^{x} + e^{\mathsf{neg}\left(x\right)}}{2}}} \]
    2. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \color{blue}{\left(\frac{e^{x} + e^{\mathsf{neg}\left(x\right)}}{2}\right)}\right) \]
    3. cosh-defN/A

      \[\leadsto \mathsf{/.f64}\left(1, \cosh x\right) \]
    4. cosh-lowering-cosh.f64100.0%

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{cosh.f64}\left(x\right)\right) \]
  4. Applied egg-rr100.0%

    \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
  5. Taylor expanded in x around 0

    \[\leadsto \mathsf{/.f64}\left(1, \color{blue}{\left(1 + {x}^{2} \cdot \left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)\right)}\right) \]
  6. Step-by-step derivation
    1. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \color{blue}{\left({x}^{2} \cdot \left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)\right)}\right)\right) \]
    2. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)}\right)\right)\right) \]
    3. unpow2N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\left(x \cdot x\right), \left(\color{blue}{\frac{1}{2}} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)\right)\right)\right) \]
    4. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\color{blue}{\frac{1}{2}} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)\right)\right)\right) \]
    5. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \color{blue}{\left({x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)}\right)\right)\right)\right) \]
    6. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right) \]
    7. unpow2N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left(x \cdot x\right), \left(\color{blue}{\frac{1}{24}} + \frac{1}{720} \cdot {x}^{2}\right)\right)\right)\right)\right)\right) \]
    8. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\color{blue}{\frac{1}{24}} + \frac{1}{720} \cdot {x}^{2}\right)\right)\right)\right)\right)\right) \]
    9. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{24}, \color{blue}{\left(\frac{1}{720} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right)\right) \]
    10. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{24}, \left({x}^{2} \cdot \color{blue}{\frac{1}{720}}\right)\right)\right)\right)\right)\right)\right) \]
    11. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{24}, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\frac{1}{720}}\right)\right)\right)\right)\right)\right)\right) \]
    12. unpow2N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{24}, \mathsf{*.f64}\left(\left(x \cdot x\right), \frac{1}{720}\right)\right)\right)\right)\right)\right)\right) \]
    13. *-lowering-*.f6493.4%

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{24}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \frac{1}{720}\right)\right)\right)\right)\right)\right)\right) \]
  7. Simplified93.4%

    \[\leadsto \frac{1}{\color{blue}{1 + \left(x \cdot x\right) \cdot \left(0.5 + \left(x \cdot x\right) \cdot \left(0.041666666666666664 + \left(x \cdot x\right) \cdot 0.001388888888888889\right)\right)}} \]
  8. Taylor expanded in x around inf

    \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \color{blue}{\left(\frac{1}{720} \cdot {x}^{4}\right)}\right)\right)\right)\right) \]
  9. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \left({x}^{4} \cdot \color{blue}{\frac{1}{720}}\right)\right)\right)\right)\right) \]
    2. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left({x}^{4}\right), \color{blue}{\frac{1}{720}}\right)\right)\right)\right)\right) \]
    3. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left({x}^{\left(3 + 1\right)}\right), \frac{1}{720}\right)\right)\right)\right)\right) \]
    4. pow-plusN/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left({x}^{3} \cdot x\right), \frac{1}{720}\right)\right)\right)\right)\right) \]
    5. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left(x \cdot {x}^{3}\right), \frac{1}{720}\right)\right)\right)\right)\right) \]
    6. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \left({x}^{3}\right)\right), \frac{1}{720}\right)\right)\right)\right)\right) \]
    7. cube-multN/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \left(x \cdot \left(x \cdot x\right)\right)\right), \frac{1}{720}\right)\right)\right)\right)\right) \]
    8. unpow2N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \left(x \cdot {x}^{2}\right)\right), \frac{1}{720}\right)\right)\right)\right)\right) \]
    9. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \left({x}^{2}\right)\right)\right), \frac{1}{720}\right)\right)\right)\right)\right) \]
    10. unpow2N/A

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \left(x \cdot x\right)\right)\right), \frac{1}{720}\right)\right)\right)\right)\right) \]
    11. *-lowering-*.f6493.4%

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right)\right), \frac{1}{720}\right)\right)\right)\right)\right) \]
  10. Simplified93.4%

    \[\leadsto \frac{1}{1 + \left(x \cdot x\right) \cdot \left(0.5 + \color{blue}{\left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right) \cdot 0.001388888888888889}\right)} \]
  11. Final simplification93.4%

    \[\leadsto \frac{1}{1 + \left(x \cdot x\right) \cdot \left(0.5 + 0.001388888888888889 \cdot \left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right)\right)} \]
  12. Add Preprocessing

Alternative 4: 71.7% accurate, 11.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := x \cdot \left(x \cdot x\right)\\ \mathbf{if}\;x \leq 1.4:\\ \;\;\;\;1 + \left(x \cdot x\right) \cdot -0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{720}{t\_0 \cdot t\_0}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (* x (* x x))))
   (if (<= x 1.4) (+ 1.0 (* (* x x) -0.5)) (/ 720.0 (* t_0 t_0)))))
double code(double x) {
	double t_0 = x * (x * x);
	double tmp;
	if (x <= 1.4) {
		tmp = 1.0 + ((x * x) * -0.5);
	} else {
		tmp = 720.0 / (t_0 * t_0);
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: tmp
    t_0 = x * (x * x)
    if (x <= 1.4d0) then
        tmp = 1.0d0 + ((x * x) * (-0.5d0))
    else
        tmp = 720.0d0 / (t_0 * t_0)
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = x * (x * x);
	double tmp;
	if (x <= 1.4) {
		tmp = 1.0 + ((x * x) * -0.5);
	} else {
		tmp = 720.0 / (t_0 * t_0);
	}
	return tmp;
}
def code(x):
	t_0 = x * (x * x)
	tmp = 0
	if x <= 1.4:
		tmp = 1.0 + ((x * x) * -0.5)
	else:
		tmp = 720.0 / (t_0 * t_0)
	return tmp
function code(x)
	t_0 = Float64(x * Float64(x * x))
	tmp = 0.0
	if (x <= 1.4)
		tmp = Float64(1.0 + Float64(Float64(x * x) * -0.5));
	else
		tmp = Float64(720.0 / Float64(t_0 * t_0));
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = x * (x * x);
	tmp = 0.0;
	if (x <= 1.4)
		tmp = 1.0 + ((x * x) * -0.5);
	else
		tmp = 720.0 / (t_0 * t_0);
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[x, 1.4], N[(1.0 + N[(N[(x * x), $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision], N[(720.0 / N[(t$95$0 * t$95$0), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := x \cdot \left(x \cdot x\right)\\
\mathbf{if}\;x \leq 1.4:\\
\;\;\;\;1 + \left(x \cdot x\right) \cdot -0.5\\

\mathbf{else}:\\
\;\;\;\;\frac{720}{t\_0 \cdot t\_0}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.3999999999999999

    1. Initial program 100.0%

      \[\frac{2}{e^{x} + e^{-x}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{1 + \frac{-1}{2} \cdot {x}^{2}} \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(1, \color{blue}{\left(\frac{-1}{2} \cdot {x}^{2}\right)}\right) \]
      2. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\frac{-1}{2}, \color{blue}{\left({x}^{2}\right)}\right)\right) \]
      3. unpow2N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\frac{-1}{2}, \left(x \cdot \color{blue}{x}\right)\right)\right) \]
      4. *-lowering-*.f6470.8%

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right) \]
    5. Simplified70.8%

      \[\leadsto \color{blue}{1 + -0.5 \cdot \left(x \cdot x\right)} \]

    if 1.3999999999999999 < x

    1. Initial program 100.0%

      \[\frac{2}{e^{x} + e^{-x}} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. clear-numN/A

        \[\leadsto \frac{1}{\color{blue}{\frac{e^{x} + e^{\mathsf{neg}\left(x\right)}}{2}}} \]
      2. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \color{blue}{\left(\frac{e^{x} + e^{\mathsf{neg}\left(x\right)}}{2}\right)}\right) \]
      3. cosh-defN/A

        \[\leadsto \mathsf{/.f64}\left(1, \cosh x\right) \]
      4. cosh-lowering-cosh.f64100.0%

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{cosh.f64}\left(x\right)\right) \]
    4. Applied egg-rr100.0%

      \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
    5. Taylor expanded in x around 0

      \[\leadsto \mathsf{/.f64}\left(1, \color{blue}{\left(1 + {x}^{2} \cdot \left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)\right)}\right) \]
    6. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \color{blue}{\left({x}^{2} \cdot \left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)\right)}\right)\right) \]
      2. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)}\right)\right)\right) \]
      3. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\left(x \cdot x\right), \left(\color{blue}{\frac{1}{2}} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)\right)\right)\right) \]
      4. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\color{blue}{\frac{1}{2}} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)\right)\right)\right) \]
      5. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \color{blue}{\left({x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)}\right)\right)\right)\right) \]
      6. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right) \]
      7. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left(x \cdot x\right), \left(\color{blue}{\frac{1}{24}} + \frac{1}{720} \cdot {x}^{2}\right)\right)\right)\right)\right)\right) \]
      8. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\color{blue}{\frac{1}{24}} + \frac{1}{720} \cdot {x}^{2}\right)\right)\right)\right)\right)\right) \]
      9. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{24}, \color{blue}{\left(\frac{1}{720} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right)\right) \]
      10. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{24}, \left({x}^{2} \cdot \color{blue}{\frac{1}{720}}\right)\right)\right)\right)\right)\right)\right) \]
      11. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{24}, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\frac{1}{720}}\right)\right)\right)\right)\right)\right)\right) \]
      12. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{24}, \mathsf{*.f64}\left(\left(x \cdot x\right), \frac{1}{720}\right)\right)\right)\right)\right)\right)\right) \]
      13. *-lowering-*.f6489.0%

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{24}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \frac{1}{720}\right)\right)\right)\right)\right)\right)\right) \]
    7. Simplified89.0%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(x \cdot x\right) \cdot \left(0.5 + \left(x \cdot x\right) \cdot \left(0.041666666666666664 + \left(x \cdot x\right) \cdot 0.001388888888888889\right)\right)}} \]
    8. Taylor expanded in x around inf

      \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \color{blue}{\left(\frac{1}{720} \cdot {x}^{4}\right)}\right)\right)\right)\right) \]
    9. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \left({x}^{4} \cdot \color{blue}{\frac{1}{720}}\right)\right)\right)\right)\right) \]
      2. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left({x}^{4}\right), \color{blue}{\frac{1}{720}}\right)\right)\right)\right)\right) \]
      3. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left({x}^{\left(3 + 1\right)}\right), \frac{1}{720}\right)\right)\right)\right)\right) \]
      4. pow-plusN/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left({x}^{3} \cdot x\right), \frac{1}{720}\right)\right)\right)\right)\right) \]
      5. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left(x \cdot {x}^{3}\right), \frac{1}{720}\right)\right)\right)\right)\right) \]
      6. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \left({x}^{3}\right)\right), \frac{1}{720}\right)\right)\right)\right)\right) \]
      7. cube-multN/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \left(x \cdot \left(x \cdot x\right)\right)\right), \frac{1}{720}\right)\right)\right)\right)\right) \]
      8. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \left(x \cdot {x}^{2}\right)\right), \frac{1}{720}\right)\right)\right)\right)\right) \]
      9. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \left({x}^{2}\right)\right)\right), \frac{1}{720}\right)\right)\right)\right)\right) \]
      10. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \left(x \cdot x\right)\right)\right), \frac{1}{720}\right)\right)\right)\right)\right) \]
      11. *-lowering-*.f6489.0%

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right)\right), \frac{1}{720}\right)\right)\right)\right)\right) \]
    10. Simplified89.0%

      \[\leadsto \frac{1}{1 + \left(x \cdot x\right) \cdot \left(0.5 + \color{blue}{\left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right) \cdot 0.001388888888888889}\right)} \]
    11. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{720}{{x}^{6}}} \]
    12. Step-by-step derivation
      1. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(720, \color{blue}{\left({x}^{6}\right)}\right) \]
      2. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(720, \left({x}^{\left(5 + \color{blue}{1}\right)}\right)\right) \]
      3. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(720, \left({x}^{\left(\left(4 + 1\right) + 1\right)}\right)\right) \]
      4. pow-plusN/A

        \[\leadsto \mathsf{/.f64}\left(720, \left({x}^{\left(4 + 1\right)} \cdot \color{blue}{x}\right)\right) \]
      5. pow-plusN/A

        \[\leadsto \mathsf{/.f64}\left(720, \left(\left({x}^{4} \cdot x\right) \cdot x\right)\right) \]
      6. associate-*r*N/A

        \[\leadsto \mathsf{/.f64}\left(720, \left({x}^{4} \cdot \color{blue}{\left(x \cdot x\right)}\right)\right) \]
      7. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(720, \left({x}^{4} \cdot {x}^{\color{blue}{2}}\right)\right) \]
      8. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(720, \left({x}^{\left(3 + 1\right)} \cdot {x}^{2}\right)\right) \]
      9. pow-plusN/A

        \[\leadsto \mathsf{/.f64}\left(720, \left(\left({x}^{3} \cdot x\right) \cdot {\color{blue}{x}}^{2}\right)\right) \]
      10. associate-*l*N/A

        \[\leadsto \mathsf{/.f64}\left(720, \left({x}^{3} \cdot \color{blue}{\left(x \cdot {x}^{2}\right)}\right)\right) \]
      11. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(720, \left({x}^{3} \cdot \left(x \cdot \left(x \cdot \color{blue}{x}\right)\right)\right)\right) \]
      12. cube-multN/A

        \[\leadsto \mathsf{/.f64}\left(720, \left({x}^{3} \cdot {x}^{\color{blue}{3}}\right)\right) \]
      13. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(720, \mathsf{*.f64}\left(\left({x}^{3}\right), \color{blue}{\left({x}^{3}\right)}\right)\right) \]
      14. cube-multN/A

        \[\leadsto \mathsf{/.f64}\left(720, \mathsf{*.f64}\left(\left(x \cdot \left(x \cdot x\right)\right), \left({\color{blue}{x}}^{3}\right)\right)\right) \]
      15. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(720, \mathsf{*.f64}\left(\left(x \cdot {x}^{2}\right), \left({x}^{3}\right)\right)\right) \]
      16. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(720, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \left({x}^{2}\right)\right), \left({\color{blue}{x}}^{3}\right)\right)\right) \]
      17. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(720, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \left(x \cdot x\right)\right), \left({x}^{3}\right)\right)\right) \]
      18. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(720, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right), \left({x}^{3}\right)\right)\right) \]
      19. cube-multN/A

        \[\leadsto \mathsf{/.f64}\left(720, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right), \left(x \cdot \color{blue}{\left(x \cdot x\right)}\right)\right)\right) \]
      20. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(720, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right), \left(x \cdot {x}^{\color{blue}{2}}\right)\right)\right) \]
      21. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(720, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right), \mathsf{*.f64}\left(x, \color{blue}{\left({x}^{2}\right)}\right)\right)\right) \]
      22. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(720, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right), \mathsf{*.f64}\left(x, \left(x \cdot \color{blue}{x}\right)\right)\right)\right) \]
      23. *-lowering-*.f6489.0%

        \[\leadsto \mathsf{/.f64}\left(720, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right), \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right)\right) \]
    13. Simplified89.0%

      \[\leadsto \color{blue}{\frac{720}{\left(x \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot \left(x \cdot x\right)\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification75.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1.4:\\ \;\;\;\;1 + \left(x \cdot x\right) \cdot -0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{720}{\left(x \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot \left(x \cdot x\right)\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 69.6% accurate, 11.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.2:\\ \;\;\;\;1 + \left(x \cdot x\right) \cdot -0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{2}{x \cdot \left(x \cdot \left(1 + \left(x \cdot x\right) \cdot 0.08333333333333333\right)\right)}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.2)
   (+ 1.0 (* (* x x) -0.5))
   (/ 2.0 (* x (* x (+ 1.0 (* (* x x) 0.08333333333333333)))))))
double code(double x) {
	double tmp;
	if (x <= 1.2) {
		tmp = 1.0 + ((x * x) * -0.5);
	} else {
		tmp = 2.0 / (x * (x * (1.0 + ((x * x) * 0.08333333333333333))));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 1.2d0) then
        tmp = 1.0d0 + ((x * x) * (-0.5d0))
    else
        tmp = 2.0d0 / (x * (x * (1.0d0 + ((x * x) * 0.08333333333333333d0))))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 1.2) {
		tmp = 1.0 + ((x * x) * -0.5);
	} else {
		tmp = 2.0 / (x * (x * (1.0 + ((x * x) * 0.08333333333333333))));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 1.2:
		tmp = 1.0 + ((x * x) * -0.5)
	else:
		tmp = 2.0 / (x * (x * (1.0 + ((x * x) * 0.08333333333333333))))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 1.2)
		tmp = Float64(1.0 + Float64(Float64(x * x) * -0.5));
	else
		tmp = Float64(2.0 / Float64(x * Float64(x * Float64(1.0 + Float64(Float64(x * x) * 0.08333333333333333)))));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 1.2)
		tmp = 1.0 + ((x * x) * -0.5);
	else
		tmp = 2.0 / (x * (x * (1.0 + ((x * x) * 0.08333333333333333))));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 1.2], N[(1.0 + N[(N[(x * x), $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision], N[(2.0 / N[(x * N[(x * N[(1.0 + N[(N[(x * x), $MachinePrecision] * 0.08333333333333333), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.2:\\
\;\;\;\;1 + \left(x \cdot x\right) \cdot -0.5\\

\mathbf{else}:\\
\;\;\;\;\frac{2}{x \cdot \left(x \cdot \left(1 + \left(x \cdot x\right) \cdot 0.08333333333333333\right)\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.19999999999999996

    1. Initial program 100.0%

      \[\frac{2}{e^{x} + e^{-x}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{1 + \frac{-1}{2} \cdot {x}^{2}} \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(1, \color{blue}{\left(\frac{-1}{2} \cdot {x}^{2}\right)}\right) \]
      2. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\frac{-1}{2}, \color{blue}{\left({x}^{2}\right)}\right)\right) \]
      3. unpow2N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\frac{-1}{2}, \left(x \cdot \color{blue}{x}\right)\right)\right) \]
      4. *-lowering-*.f6470.8%

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right) \]
    5. Simplified70.8%

      \[\leadsto \color{blue}{1 + -0.5 \cdot \left(x \cdot x\right)} \]

    if 1.19999999999999996 < x

    1. Initial program 100.0%

      \[\frac{2}{e^{x} + e^{-x}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \mathsf{/.f64}\left(2, \color{blue}{\left(2 + {x}^{2} \cdot \left(1 + \frac{1}{12} \cdot {x}^{2}\right)\right)}\right) \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \color{blue}{\left({x}^{2} \cdot \left(1 + \frac{1}{12} \cdot {x}^{2}\right)\right)}\right)\right) \]
      2. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \left(\left(x \cdot x\right) \cdot \left(\color{blue}{1} + \frac{1}{12} \cdot {x}^{2}\right)\right)\right)\right) \]
      3. associate-*l*N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \left(x \cdot \color{blue}{\left(x \cdot \left(1 + \frac{1}{12} \cdot {x}^{2}\right)\right)}\right)\right)\right) \]
      4. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \left(x \cdot \left(\left(1 + \frac{1}{12} \cdot {x}^{2}\right) \cdot \color{blue}{x}\right)\right)\right)\right) \]
      5. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \color{blue}{\left(\left(1 + \frac{1}{12} \cdot {x}^{2}\right) \cdot x\right)}\right)\right)\right) \]
      6. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \left(x \cdot \color{blue}{\left(1 + \frac{1}{12} \cdot {x}^{2}\right)}\right)\right)\right)\right) \]
      7. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{\left(1 + \frac{1}{12} \cdot {x}^{2}\right)}\right)\right)\right)\right) \]
      8. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \color{blue}{\left(\frac{1}{12} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right) \]
      9. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \left({x}^{2} \cdot \color{blue}{\frac{1}{12}}\right)\right)\right)\right)\right)\right) \]
      10. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\frac{1}{12}}\right)\right)\right)\right)\right)\right) \]
      11. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\left(x \cdot x\right), \frac{1}{12}\right)\right)\right)\right)\right)\right) \]
      12. *-lowering-*.f6475.1%

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \frac{1}{12}\right)\right)\right)\right)\right)\right) \]
    5. Simplified75.1%

      \[\leadsto \frac{2}{\color{blue}{2 + x \cdot \left(x \cdot \left(1 + \left(x \cdot x\right) \cdot 0.08333333333333333\right)\right)}} \]
    6. Taylor expanded in x around inf

      \[\leadsto \mathsf{/.f64}\left(2, \color{blue}{\left({x}^{4} \cdot \left(\frac{1}{12} + \frac{1}{{x}^{2}}\right)\right)}\right) \]
    7. Step-by-step derivation
      1. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(2, \left({x}^{\left(3 + 1\right)} \cdot \left(\frac{1}{12} + \frac{1}{{x}^{2}}\right)\right)\right) \]
      2. pow-plusN/A

        \[\leadsto \mathsf{/.f64}\left(2, \left(\left({x}^{3} \cdot x\right) \cdot \left(\color{blue}{\frac{1}{12}} + \frac{1}{{x}^{2}}\right)\right)\right) \]
      3. unpow3N/A

        \[\leadsto \mathsf{/.f64}\left(2, \left(\left(\left(\left(x \cdot x\right) \cdot x\right) \cdot x\right) \cdot \left(\frac{1}{12} + \frac{1}{{x}^{2}}\right)\right)\right) \]
      4. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(2, \left(\left(\left({x}^{2} \cdot x\right) \cdot x\right) \cdot \left(\frac{1}{12} + \frac{1}{{x}^{2}}\right)\right)\right) \]
      5. associate-*r*N/A

        \[\leadsto \mathsf{/.f64}\left(2, \left(\left({x}^{2} \cdot \left(x \cdot x\right)\right) \cdot \left(\color{blue}{\frac{1}{12}} + \frac{1}{{x}^{2}}\right)\right)\right) \]
      6. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(2, \left(\left({x}^{2} \cdot {x}^{2}\right) \cdot \left(\frac{1}{12} + \frac{1}{{x}^{2}}\right)\right)\right) \]
      7. +-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(2, \left(\left({x}^{2} \cdot {x}^{2}\right) \cdot \left(\frac{1}{{x}^{2}} + \color{blue}{\frac{1}{12}}\right)\right)\right) \]
      8. distribute-rgt-inN/A

        \[\leadsto \mathsf{/.f64}\left(2, \left(\frac{1}{{x}^{2}} \cdot \left({x}^{2} \cdot {x}^{2}\right) + \color{blue}{\frac{1}{12} \cdot \left({x}^{2} \cdot {x}^{2}\right)}\right)\right) \]
    8. Simplified75.1%

      \[\leadsto \frac{2}{\color{blue}{x \cdot \left(x \cdot \left(1 + \left(x \cdot x\right) \cdot 0.08333333333333333\right)\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification71.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1.2:\\ \;\;\;\;1 + \left(x \cdot x\right) \cdot -0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{2}{x \cdot \left(x \cdot \left(1 + \left(x \cdot x\right) \cdot 0.08333333333333333\right)\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 69.6% accurate, 14.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.38:\\ \;\;\;\;1 + \left(x \cdot x\right) \cdot -0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{24}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.38) (+ 1.0 (* (* x x) -0.5)) (/ 24.0 (* x (* x (* x x))))))
double code(double x) {
	double tmp;
	if (x <= 1.38) {
		tmp = 1.0 + ((x * x) * -0.5);
	} else {
		tmp = 24.0 / (x * (x * (x * x)));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 1.38d0) then
        tmp = 1.0d0 + ((x * x) * (-0.5d0))
    else
        tmp = 24.0d0 / (x * (x * (x * x)))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 1.38) {
		tmp = 1.0 + ((x * x) * -0.5);
	} else {
		tmp = 24.0 / (x * (x * (x * x)));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 1.38:
		tmp = 1.0 + ((x * x) * -0.5)
	else:
		tmp = 24.0 / (x * (x * (x * x)))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 1.38)
		tmp = Float64(1.0 + Float64(Float64(x * x) * -0.5));
	else
		tmp = Float64(24.0 / Float64(x * Float64(x * Float64(x * x))));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 1.38)
		tmp = 1.0 + ((x * x) * -0.5);
	else
		tmp = 24.0 / (x * (x * (x * x)));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 1.38], N[(1.0 + N[(N[(x * x), $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision], N[(24.0 / N[(x * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.38:\\
\;\;\;\;1 + \left(x \cdot x\right) \cdot -0.5\\

\mathbf{else}:\\
\;\;\;\;\frac{24}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.3799999999999999

    1. Initial program 100.0%

      \[\frac{2}{e^{x} + e^{-x}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{1 + \frac{-1}{2} \cdot {x}^{2}} \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(1, \color{blue}{\left(\frac{-1}{2} \cdot {x}^{2}\right)}\right) \]
      2. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\frac{-1}{2}, \color{blue}{\left({x}^{2}\right)}\right)\right) \]
      3. unpow2N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\frac{-1}{2}, \left(x \cdot \color{blue}{x}\right)\right)\right) \]
      4. *-lowering-*.f6470.8%

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right) \]
    5. Simplified70.8%

      \[\leadsto \color{blue}{1 + -0.5 \cdot \left(x \cdot x\right)} \]

    if 1.3799999999999999 < x

    1. Initial program 100.0%

      \[\frac{2}{e^{x} + e^{-x}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \mathsf{/.f64}\left(2, \color{blue}{\left(2 + {x}^{2} \cdot \left(1 + \frac{1}{12} \cdot {x}^{2}\right)\right)}\right) \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \color{blue}{\left({x}^{2} \cdot \left(1 + \frac{1}{12} \cdot {x}^{2}\right)\right)}\right)\right) \]
      2. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \left(\left(x \cdot x\right) \cdot \left(\color{blue}{1} + \frac{1}{12} \cdot {x}^{2}\right)\right)\right)\right) \]
      3. associate-*l*N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \left(x \cdot \color{blue}{\left(x \cdot \left(1 + \frac{1}{12} \cdot {x}^{2}\right)\right)}\right)\right)\right) \]
      4. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \left(x \cdot \left(\left(1 + \frac{1}{12} \cdot {x}^{2}\right) \cdot \color{blue}{x}\right)\right)\right)\right) \]
      5. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \color{blue}{\left(\left(1 + \frac{1}{12} \cdot {x}^{2}\right) \cdot x\right)}\right)\right)\right) \]
      6. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \left(x \cdot \color{blue}{\left(1 + \frac{1}{12} \cdot {x}^{2}\right)}\right)\right)\right)\right) \]
      7. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{\left(1 + \frac{1}{12} \cdot {x}^{2}\right)}\right)\right)\right)\right) \]
      8. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \color{blue}{\left(\frac{1}{12} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right) \]
      9. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \left({x}^{2} \cdot \color{blue}{\frac{1}{12}}\right)\right)\right)\right)\right)\right) \]
      10. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\frac{1}{12}}\right)\right)\right)\right)\right)\right) \]
      11. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\left(x \cdot x\right), \frac{1}{12}\right)\right)\right)\right)\right)\right) \]
      12. *-lowering-*.f6475.1%

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \frac{1}{12}\right)\right)\right)\right)\right)\right) \]
    5. Simplified75.1%

      \[\leadsto \frac{2}{\color{blue}{2 + x \cdot \left(x \cdot \left(1 + \left(x \cdot x\right) \cdot 0.08333333333333333\right)\right)}} \]
    6. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{24}{{x}^{4}}} \]
    7. Step-by-step derivation
      1. metadata-evalN/A

        \[\leadsto \frac{24}{{x}^{\left(3 + \color{blue}{1}\right)}} \]
      2. pow-plusN/A

        \[\leadsto \frac{24}{{x}^{3} \cdot \color{blue}{x}} \]
      3. unpow3N/A

        \[\leadsto \frac{24}{\left(\left(x \cdot x\right) \cdot x\right) \cdot x} \]
      4. unpow2N/A

        \[\leadsto \frac{24}{\left({x}^{2} \cdot x\right) \cdot x} \]
      5. associate-*r*N/A

        \[\leadsto \frac{24}{{x}^{2} \cdot \color{blue}{\left(x \cdot x\right)}} \]
      6. unpow2N/A

        \[\leadsto \frac{24}{{x}^{2} \cdot {x}^{\color{blue}{2}}} \]
      7. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(24, \color{blue}{\left({x}^{2} \cdot {x}^{2}\right)}\right) \]
      8. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(24, \left(\left(x \cdot x\right) \cdot {\color{blue}{x}}^{2}\right)\right) \]
      9. associate-*l*N/A

        \[\leadsto \mathsf{/.f64}\left(24, \left(x \cdot \color{blue}{\left(x \cdot {x}^{2}\right)}\right)\right) \]
      10. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(24, \left(x \cdot \left(x \cdot \left(x \cdot \color{blue}{x}\right)\right)\right)\right) \]
      11. cube-multN/A

        \[\leadsto \mathsf{/.f64}\left(24, \left(x \cdot {x}^{\color{blue}{3}}\right)\right) \]
      12. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(24, \mathsf{*.f64}\left(x, \color{blue}{\left({x}^{3}\right)}\right)\right) \]
      13. cube-multN/A

        \[\leadsto \mathsf{/.f64}\left(24, \mathsf{*.f64}\left(x, \left(x \cdot \color{blue}{\left(x \cdot x\right)}\right)\right)\right) \]
      14. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(24, \mathsf{*.f64}\left(x, \left(x \cdot {x}^{\color{blue}{2}}\right)\right)\right) \]
      15. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(24, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{\left({x}^{2}\right)}\right)\right)\right) \]
      16. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(24, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \left(x \cdot \color{blue}{x}\right)\right)\right)\right) \]
      17. *-lowering-*.f6475.1%

        \[\leadsto \mathsf{/.f64}\left(24, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right)\right) \]
    8. Simplified75.1%

      \[\leadsto \color{blue}{\frac{24}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification71.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1.38:\\ \;\;\;\;1 + \left(x \cdot x\right) \cdot -0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{24}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 63.7% accurate, 17.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.25:\\ \;\;\;\;1 + \left(x \cdot x\right) \cdot -0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{2}{x \cdot x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.25) (+ 1.0 (* (* x x) -0.5)) (/ 2.0 (* x x))))
double code(double x) {
	double tmp;
	if (x <= 1.25) {
		tmp = 1.0 + ((x * x) * -0.5);
	} else {
		tmp = 2.0 / (x * x);
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 1.25d0) then
        tmp = 1.0d0 + ((x * x) * (-0.5d0))
    else
        tmp = 2.0d0 / (x * x)
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 1.25) {
		tmp = 1.0 + ((x * x) * -0.5);
	} else {
		tmp = 2.0 / (x * x);
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 1.25:
		tmp = 1.0 + ((x * x) * -0.5)
	else:
		tmp = 2.0 / (x * x)
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 1.25)
		tmp = Float64(1.0 + Float64(Float64(x * x) * -0.5));
	else
		tmp = Float64(2.0 / Float64(x * x));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 1.25)
		tmp = 1.0 + ((x * x) * -0.5);
	else
		tmp = 2.0 / (x * x);
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 1.25], N[(1.0 + N[(N[(x * x), $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision], N[(2.0 / N[(x * x), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.25:\\
\;\;\;\;1 + \left(x \cdot x\right) \cdot -0.5\\

\mathbf{else}:\\
\;\;\;\;\frac{2}{x \cdot x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.25

    1. Initial program 100.0%

      \[\frac{2}{e^{x} + e^{-x}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{1 + \frac{-1}{2} \cdot {x}^{2}} \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(1, \color{blue}{\left(\frac{-1}{2} \cdot {x}^{2}\right)}\right) \]
      2. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\frac{-1}{2}, \color{blue}{\left({x}^{2}\right)}\right)\right) \]
      3. unpow2N/A

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\frac{-1}{2}, \left(x \cdot \color{blue}{x}\right)\right)\right) \]
      4. *-lowering-*.f6470.8%

        \[\leadsto \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\frac{-1}{2}, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right) \]
    5. Simplified70.8%

      \[\leadsto \color{blue}{1 + -0.5 \cdot \left(x \cdot x\right)} \]

    if 1.25 < x

    1. Initial program 100.0%

      \[\frac{2}{e^{x} + e^{-x}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \mathsf{/.f64}\left(2, \color{blue}{\left(2 + {x}^{2}\right)}\right) \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \color{blue}{\left({x}^{2}\right)}\right)\right) \]
      2. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \left(x \cdot \color{blue}{x}\right)\right)\right) \]
      3. *-lowering-*.f6456.9%

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right) \]
    5. Simplified56.9%

      \[\leadsto \frac{2}{\color{blue}{2 + x \cdot x}} \]
    6. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{2}{{x}^{2}}} \]
    7. Step-by-step derivation
      1. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \color{blue}{\left({x}^{2}\right)}\right) \]
      2. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(2, \left(x \cdot \color{blue}{x}\right)\right) \]
      3. *-lowering-*.f6456.9%

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right) \]
    8. Simplified56.9%

      \[\leadsto \color{blue}{\frac{2}{x \cdot x}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification67.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1.25:\\ \;\;\;\;1 + \left(x \cdot x\right) \cdot -0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{2}{x \cdot x}\\ \end{array} \]
  5. Add Preprocessing

Alternative 8: 63.7% accurate, 20.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.4:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;\frac{2}{x \cdot x}\\ \end{array} \end{array} \]
(FPCore (x) :precision binary64 (if (<= x 1.4) 1.0 (/ 2.0 (* x x))))
double code(double x) {
	double tmp;
	if (x <= 1.4) {
		tmp = 1.0;
	} else {
		tmp = 2.0 / (x * x);
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 1.4d0) then
        tmp = 1.0d0
    else
        tmp = 2.0d0 / (x * x)
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 1.4) {
		tmp = 1.0;
	} else {
		tmp = 2.0 / (x * x);
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 1.4:
		tmp = 1.0
	else:
		tmp = 2.0 / (x * x)
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 1.4)
		tmp = 1.0;
	else
		tmp = Float64(2.0 / Float64(x * x));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 1.4)
		tmp = 1.0;
	else
		tmp = 2.0 / (x * x);
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 1.4], 1.0, N[(2.0 / N[(x * x), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.4:\\
\;\;\;\;1\\

\mathbf{else}:\\
\;\;\;\;\frac{2}{x \cdot x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.3999999999999999

    1. Initial program 100.0%

      \[\frac{2}{e^{x} + e^{-x}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{1} \]
    4. Step-by-step derivation
      1. Simplified70.8%

        \[\leadsto \color{blue}{1} \]

      if 1.3999999999999999 < x

      1. Initial program 100.0%

        \[\frac{2}{e^{x} + e^{-x}} \]
      2. Add Preprocessing
      3. Taylor expanded in x around 0

        \[\leadsto \mathsf{/.f64}\left(2, \color{blue}{\left(2 + {x}^{2}\right)}\right) \]
      4. Step-by-step derivation
        1. +-lowering-+.f64N/A

          \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \color{blue}{\left({x}^{2}\right)}\right)\right) \]
        2. unpow2N/A

          \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \left(x \cdot \color{blue}{x}\right)\right)\right) \]
        3. *-lowering-*.f6456.9%

          \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right) \]
      5. Simplified56.9%

        \[\leadsto \frac{2}{\color{blue}{2 + x \cdot x}} \]
      6. Taylor expanded in x around inf

        \[\leadsto \color{blue}{\frac{2}{{x}^{2}}} \]
      7. Step-by-step derivation
        1. /-lowering-/.f64N/A

          \[\leadsto \mathsf{/.f64}\left(2, \color{blue}{\left({x}^{2}\right)}\right) \]
        2. unpow2N/A

          \[\leadsto \mathsf{/.f64}\left(2, \left(x \cdot \color{blue}{x}\right)\right) \]
        3. *-lowering-*.f6456.9%

          \[\leadsto \mathsf{/.f64}\left(2, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right) \]
      8. Simplified56.9%

        \[\leadsto \color{blue}{\frac{2}{x \cdot x}} \]
    5. Recombined 2 regimes into one program.
    6. Add Preprocessing

    Alternative 9: 76.5% accurate, 29.4× speedup?

    \[\begin{array}{l} \\ \frac{2}{x \cdot x + 2} \end{array} \]
    (FPCore (x) :precision binary64 (/ 2.0 (+ (* x x) 2.0)))
    double code(double x) {
    	return 2.0 / ((x * x) + 2.0);
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        code = 2.0d0 / ((x * x) + 2.0d0)
    end function
    
    public static double code(double x) {
    	return 2.0 / ((x * x) + 2.0);
    }
    
    def code(x):
    	return 2.0 / ((x * x) + 2.0)
    
    function code(x)
    	return Float64(2.0 / Float64(Float64(x * x) + 2.0))
    end
    
    function tmp = code(x)
    	tmp = 2.0 / ((x * x) + 2.0);
    end
    
    code[x_] := N[(2.0 / N[(N[(x * x), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{2}{x \cdot x + 2}
    \end{array}
    
    Derivation
    1. Initial program 100.0%

      \[\frac{2}{e^{x} + e^{-x}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \mathsf{/.f64}\left(2, \color{blue}{\left(2 + {x}^{2}\right)}\right) \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \color{blue}{\left({x}^{2}\right)}\right)\right) \]
      2. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \left(x \cdot \color{blue}{x}\right)\right)\right) \]
      3. *-lowering-*.f6479.2%

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right) \]
    5. Simplified79.2%

      \[\leadsto \frac{2}{\color{blue}{2 + x \cdot x}} \]
    6. Final simplification79.2%

      \[\leadsto \frac{2}{x \cdot x + 2} \]
    7. Add Preprocessing

    Alternative 10: 51.3% accurate, 206.0× speedup?

    \[\begin{array}{l} \\ 1 \end{array} \]
    (FPCore (x) :precision binary64 1.0)
    double code(double x) {
    	return 1.0;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        code = 1.0d0
    end function
    
    public static double code(double x) {
    	return 1.0;
    }
    
    def code(x):
    	return 1.0
    
    function code(x)
    	return 1.0
    end
    
    function tmp = code(x)
    	tmp = 1.0;
    end
    
    code[x_] := 1.0
    
    \begin{array}{l}
    
    \\
    1
    \end{array}
    
    Derivation
    1. Initial program 100.0%

      \[\frac{2}{e^{x} + e^{-x}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{1} \]
    4. Step-by-step derivation
      1. Simplified52.8%

        \[\leadsto \color{blue}{1} \]
      2. Add Preprocessing

      Reproduce

      ?
      herbie shell --seed 2024164 
      (FPCore (x)
        :name "Hyperbolic secant"
        :precision binary64
        (/ 2.0 (+ (exp x) (exp (- x)))))