Hyperbolic secant

Percentage Accurate: 100.0% → 100.0%
Time: 7.4s
Alternatives: 11
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 11 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: 94.9% accurate, 7.6× speedup?

\[\begin{array}{l} \\ \frac{32}{\left(8 + \left(x \cdot x\right) \cdot \left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right)\right) \cdot \left(4 - x \cdot \left(x \cdot \left(x \cdot x + -2\right)\right)\right)} \end{array} \]
(FPCore (x)
 :precision binary64
 (/
  32.0
  (*
   (+ 8.0 (* (* x x) (* x (* x (* x x)))))
   (- 4.0 (* x (* x (+ (* x x) -2.0)))))))
double code(double x) {
	return 32.0 / ((8.0 + ((x * x) * (x * (x * (x * x))))) * (4.0 - (x * (x * ((x * x) + -2.0)))));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 32.0d0 / ((8.0d0 + ((x * x) * (x * (x * (x * x))))) * (4.0d0 - (x * (x * ((x * x) + (-2.0d0))))))
end function
public static double code(double x) {
	return 32.0 / ((8.0 + ((x * x) * (x * (x * (x * x))))) * (4.0 - (x * (x * ((x * x) + -2.0)))));
}
def code(x):
	return 32.0 / ((8.0 + ((x * x) * (x * (x * (x * x))))) * (4.0 - (x * (x * ((x * x) + -2.0)))))
function code(x)
	return Float64(32.0 / Float64(Float64(8.0 + Float64(Float64(x * x) * Float64(x * Float64(x * Float64(x * x))))) * Float64(4.0 - Float64(x * Float64(x * Float64(Float64(x * x) + -2.0))))))
end
function tmp = code(x)
	tmp = 32.0 / ((8.0 + ((x * x) * (x * (x * (x * x))))) * (4.0 - (x * (x * ((x * x) + -2.0)))));
end
code[x_] := N[(32.0 / N[(N[(8.0 + N[(N[(x * x), $MachinePrecision] * N[(x * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(4.0 - N[(x * N[(x * N[(N[(x * x), $MachinePrecision] + -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{32}{\left(8 + \left(x \cdot x\right) \cdot \left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right)\right) \cdot \left(4 - x \cdot \left(x \cdot \left(x \cdot x + -2\right)\right)\right)}
\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-*.f6477.7%

      \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right) \]
  5. Simplified77.7%

    \[\leadsto \frac{2}{\color{blue}{2 + x \cdot x}} \]
  6. Step-by-step derivation
    1. flip3-+N/A

      \[\leadsto \frac{2}{\frac{{2}^{3} + {\left(x \cdot x\right)}^{3}}{\color{blue}{2 \cdot 2 + \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right) - 2 \cdot \left(x \cdot x\right)\right)}}} \]
    2. associate-/r/N/A

      \[\leadsto \frac{2}{{2}^{3} + {\left(x \cdot x\right)}^{3}} \cdot \color{blue}{\left(2 \cdot 2 + \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right) - 2 \cdot \left(x \cdot x\right)\right)\right)} \]
    3. flip-+N/A

      \[\leadsto \frac{2}{{2}^{3} + {\left(x \cdot x\right)}^{3}} \cdot \frac{\left(2 \cdot 2\right) \cdot \left(2 \cdot 2\right) - \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right) - 2 \cdot \left(x \cdot x\right)\right) \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right) - 2 \cdot \left(x \cdot x\right)\right)}{\color{blue}{2 \cdot 2 - \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right) - 2 \cdot \left(x \cdot x\right)\right)}} \]
    4. frac-timesN/A

      \[\leadsto \frac{2 \cdot \left(\left(2 \cdot 2\right) \cdot \left(2 \cdot 2\right) - \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right) - 2 \cdot \left(x \cdot x\right)\right) \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right) - 2 \cdot \left(x \cdot x\right)\right)\right)}{\color{blue}{\left({2}^{3} + {\left(x \cdot x\right)}^{3}\right) \cdot \left(2 \cdot 2 - \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right) - 2 \cdot \left(x \cdot x\right)\right)\right)}} \]
    5. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\left(2 \cdot \left(\left(2 \cdot 2\right) \cdot \left(2 \cdot 2\right) - \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right) - 2 \cdot \left(x \cdot x\right)\right) \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right) - 2 \cdot \left(x \cdot x\right)\right)\right)\right), \color{blue}{\left(\left({2}^{3} + {\left(x \cdot x\right)}^{3}\right) \cdot \left(2 \cdot 2 - \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right) - 2 \cdot \left(x \cdot x\right)\right)\right)\right)}\right) \]
  7. Applied egg-rr52.4%

    \[\leadsto \color{blue}{\frac{2 \cdot \left(16 - \left(x \cdot x\right) \cdot \left(\left(x \cdot x + -2\right) \cdot \left(x \cdot \left(x \cdot \left(x \cdot x + -2\right)\right)\right)\right)\right)}{\left(8 + \left(x \cdot x\right) \cdot \left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right)\right) \cdot \left(4 - x \cdot \left(x \cdot \left(x \cdot x + -2\right)\right)\right)}} \]
  8. Taylor expanded in x around 0

    \[\leadsto \mathsf{/.f64}\left(\color{blue}{32}, \mathsf{*.f64}\left(\mathsf{+.f64}\left(8, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right)\right)\right)\right), \mathsf{\_.f64}\left(4, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, x\right), -2\right)\right)\right)\right)\right)\right) \]
  9. Step-by-step derivation
    1. Simplified96.9%

      \[\leadsto \frac{\color{blue}{32}}{\left(8 + \left(x \cdot x\right) \cdot \left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right)\right) \cdot \left(4 - x \cdot \left(x \cdot \left(x \cdot x + -2\right)\right)\right)} \]
    2. Add Preprocessing

    Alternative 3: 91.9% accurate, 9.8× speedup?

    \[\begin{array}{l} \\ \frac{2}{2 + \left(x \cdot x\right) \cdot \left(1 + x \cdot \left(x \cdot \left(0.08333333333333333 + \left(x \cdot x\right) \cdot 0.002777777777777778\right)\right)\right)} \end{array} \]
    (FPCore (x)
     :precision binary64
     (/
      2.0
      (+
       2.0
       (*
        (* x x)
        (+
         1.0
         (* x (* x (+ 0.08333333333333333 (* (* x x) 0.002777777777777778)))))))))
    double code(double x) {
    	return 2.0 / (2.0 + ((x * x) * (1.0 + (x * (x * (0.08333333333333333 + ((x * x) * 0.002777777777777778)))))));
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        code = 2.0d0 / (2.0d0 + ((x * x) * (1.0d0 + (x * (x * (0.08333333333333333d0 + ((x * x) * 0.002777777777777778d0)))))))
    end function
    
    public static double code(double x) {
    	return 2.0 / (2.0 + ((x * x) * (1.0 + (x * (x * (0.08333333333333333 + ((x * x) * 0.002777777777777778)))))));
    }
    
    def code(x):
    	return 2.0 / (2.0 + ((x * x) * (1.0 + (x * (x * (0.08333333333333333 + ((x * x) * 0.002777777777777778)))))))
    
    function code(x)
    	return Float64(2.0 / Float64(2.0 + Float64(Float64(x * x) * Float64(1.0 + Float64(x * Float64(x * Float64(0.08333333333333333 + Float64(Float64(x * x) * 0.002777777777777778))))))))
    end
    
    function tmp = code(x)
    	tmp = 2.0 / (2.0 + ((x * x) * (1.0 + (x * (x * (0.08333333333333333 + ((x * x) * 0.002777777777777778)))))));
    end
    
    code[x_] := N[(2.0 / N[(2.0 + N[(N[(x * x), $MachinePrecision] * N[(1.0 + N[(x * N[(x * N[(0.08333333333333333 + N[(N[(x * x), $MachinePrecision] * 0.002777777777777778), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{2}{2 + \left(x \cdot x\right) \cdot \left(1 + x \cdot \left(x \cdot \left(0.08333333333333333 + \left(x \cdot x\right) \cdot 0.002777777777777778\right)\right)\right)}
    \end{array}
    
    Derivation
    1. Initial program 100.0%

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

      \[\leadsto \mathsf{/.f64}\left(2, \color{blue}{\left(2 + {x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right)\right)}\right) \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \color{blue}{\left({x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right)\right)}\right)\right) \]
      2. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\left(1 + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right)}\right)\right)\right) \]
      3. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\left(x \cdot x\right), \left(\color{blue}{1} + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right)\right)\right)\right) \]
      4. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\color{blue}{1} + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right)\right)\right)\right) \]
      5. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \color{blue}{\left({x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right)}\right)\right)\right)\right) \]
      6. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \left(\left(x \cdot x\right) \cdot \left(\color{blue}{\frac{1}{12}} + \frac{1}{360} \cdot {x}^{2}\right)\right)\right)\right)\right)\right) \]
      7. associate-*l*N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \left(x \cdot \color{blue}{\left(x \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right)}\right)\right)\right)\right)\right) \]
      8. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \left(x \cdot \left(\left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right) \cdot \color{blue}{x}\right)\right)\right)\right)\right)\right) \]
      9. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \color{blue}{\left(\left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right) \cdot x\right)}\right)\right)\right)\right)\right) \]
      10. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \left(x \cdot \color{blue}{\left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right)\right) \]
      11. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{\left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right)\right) \]
      12. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{12}, \color{blue}{\left(\frac{1}{360} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right)\right)\right) \]
      13. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{12}, \left({x}^{2} \cdot \color{blue}{\frac{1}{360}}\right)\right)\right)\right)\right)\right)\right)\right) \]
      14. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{12}, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\frac{1}{360}}\right)\right)\right)\right)\right)\right)\right)\right) \]
      15. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{12}, \mathsf{*.f64}\left(\left(x \cdot x\right), \frac{1}{360}\right)\right)\right)\right)\right)\right)\right)\right) \]
      16. *-lowering-*.f6492.6%

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{12}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \frac{1}{360}\right)\right)\right)\right)\right)\right)\right)\right) \]
    5. Simplified92.6%

      \[\leadsto \frac{2}{\color{blue}{2 + \left(x \cdot x\right) \cdot \left(1 + x \cdot \left(x \cdot \left(0.08333333333333333 + \left(x \cdot x\right) \cdot 0.002777777777777778\right)\right)\right)}} \]
    6. Add Preprocessing

    Alternative 4: 91.8% accurate, 10.8× speedup?

    \[\begin{array}{l} \\ \frac{2}{2 + \left(x \cdot x\right) \cdot \left(1 + x \cdot \left(x \cdot \left(\left(x \cdot x\right) \cdot 0.002777777777777778\right)\right)\right)} \end{array} \]
    (FPCore (x)
     :precision binary64
     (/
      2.0
      (+ 2.0 (* (* x x) (+ 1.0 (* x (* x (* (* x x) 0.002777777777777778))))))))
    double code(double x) {
    	return 2.0 / (2.0 + ((x * x) * (1.0 + (x * (x * ((x * x) * 0.002777777777777778))))));
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        code = 2.0d0 / (2.0d0 + ((x * x) * (1.0d0 + (x * (x * ((x * x) * 0.002777777777777778d0))))))
    end function
    
    public static double code(double x) {
    	return 2.0 / (2.0 + ((x * x) * (1.0 + (x * (x * ((x * x) * 0.002777777777777778))))));
    }
    
    def code(x):
    	return 2.0 / (2.0 + ((x * x) * (1.0 + (x * (x * ((x * x) * 0.002777777777777778))))))
    
    function code(x)
    	return Float64(2.0 / Float64(2.0 + Float64(Float64(x * x) * Float64(1.0 + Float64(x * Float64(x * Float64(Float64(x * x) * 0.002777777777777778)))))))
    end
    
    function tmp = code(x)
    	tmp = 2.0 / (2.0 + ((x * x) * (1.0 + (x * (x * ((x * x) * 0.002777777777777778))))));
    end
    
    code[x_] := N[(2.0 / N[(2.0 + N[(N[(x * x), $MachinePrecision] * N[(1.0 + N[(x * N[(x * N[(N[(x * x), $MachinePrecision] * 0.002777777777777778), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{2}{2 + \left(x \cdot x\right) \cdot \left(1 + x \cdot \left(x \cdot \left(\left(x \cdot x\right) \cdot 0.002777777777777778\right)\right)\right)}
    \end{array}
    
    Derivation
    1. Initial program 100.0%

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

      \[\leadsto \mathsf{/.f64}\left(2, \color{blue}{\left(2 + {x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right)\right)}\right) \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \color{blue}{\left({x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right)\right)}\right)\right) \]
      2. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\left(1 + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right)}\right)\right)\right) \]
      3. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\left(x \cdot x\right), \left(\color{blue}{1} + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right)\right)\right)\right) \]
      4. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\color{blue}{1} + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right)\right)\right)\right) \]
      5. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \color{blue}{\left({x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right)}\right)\right)\right)\right) \]
      6. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \left(\left(x \cdot x\right) \cdot \left(\color{blue}{\frac{1}{12}} + \frac{1}{360} \cdot {x}^{2}\right)\right)\right)\right)\right)\right) \]
      7. associate-*l*N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \left(x \cdot \color{blue}{\left(x \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right)}\right)\right)\right)\right)\right) \]
      8. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \left(x \cdot \left(\left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right) \cdot \color{blue}{x}\right)\right)\right)\right)\right)\right) \]
      9. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \color{blue}{\left(\left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right) \cdot x\right)}\right)\right)\right)\right)\right) \]
      10. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \left(x \cdot \color{blue}{\left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right)\right) \]
      11. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{\left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right)\right) \]
      12. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{12}, \color{blue}{\left(\frac{1}{360} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right)\right)\right) \]
      13. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{12}, \left({x}^{2} \cdot \color{blue}{\frac{1}{360}}\right)\right)\right)\right)\right)\right)\right)\right) \]
      14. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{12}, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\frac{1}{360}}\right)\right)\right)\right)\right)\right)\right)\right) \]
      15. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{12}, \mathsf{*.f64}\left(\left(x \cdot x\right), \frac{1}{360}\right)\right)\right)\right)\right)\right)\right)\right) \]
      16. *-lowering-*.f6492.6%

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{12}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \frac{1}{360}\right)\right)\right)\right)\right)\right)\right)\right) \]
    5. Simplified92.6%

      \[\leadsto \frac{2}{\color{blue}{2 + \left(x \cdot x\right) \cdot \left(1 + x \cdot \left(x \cdot \left(0.08333333333333333 + \left(x \cdot x\right) \cdot 0.002777777777777778\right)\right)\right)}} \]
    6. Taylor expanded in x around inf

      \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \color{blue}{\left(\frac{1}{360} \cdot {x}^{3}\right)}\right)\right)\right)\right)\right) \]
    7. Step-by-step derivation
      1. unpow3N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \left(\frac{1}{360} \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{x}\right)\right)\right)\right)\right)\right)\right) \]
      2. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \left(\frac{1}{360} \cdot \left({x}^{2} \cdot x\right)\right)\right)\right)\right)\right)\right) \]
      3. associate-*r*N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \left(\left(\frac{1}{360} \cdot {x}^{2}\right) \cdot \color{blue}{x}\right)\right)\right)\right)\right)\right) \]
      4. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \left(x \cdot \color{blue}{\left(\frac{1}{360} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right)\right) \]
      5. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{\left(\frac{1}{360} \cdot {x}^{2}\right)}\right)\right)\right)\right)\right)\right) \]
      6. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \left({x}^{2} \cdot \color{blue}{\frac{1}{360}}\right)\right)\right)\right)\right)\right)\right) \]
      7. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(\left({x}^{2}\right), \color{blue}{\frac{1}{360}}\right)\right)\right)\right)\right)\right)\right) \]
      8. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(\left(x \cdot x\right), \frac{1}{360}\right)\right)\right)\right)\right)\right)\right) \]
      9. *-lowering-*.f6492.6%

        \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \frac{1}{360}\right)\right)\right)\right)\right)\right)\right) \]
    8. Simplified92.6%

      \[\leadsto \frac{2}{2 + \left(x \cdot x\right) \cdot \left(1 + x \cdot \color{blue}{\left(x \cdot \left(\left(x \cdot x\right) \cdot 0.002777777777777778\right)\right)}\right)} \]
    9. Add Preprocessing

    Alternative 5: 87.6% accurate, 13.7× speedup?

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\left(x \cdot x\right), \frac{1}{24}\right)\right)\right)\right)\right)\right) \]
      12. *-lowering-*.f6488.9%

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \frac{1}{24}\right)\right)\right)\right)\right)\right) \]
    7. Simplified88.9%

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

    Alternative 6: 81.9% accurate, 14.7× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 700:\\ \;\;\;\;\frac{2}{x \cdot x + 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{-4}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= x 700.0) (/ 2.0 (+ (* x x) 2.0)) (/ -4.0 (* x (* x (* x x))))))
    double code(double x) {
    	double tmp;
    	if (x <= 700.0) {
    		tmp = 2.0 / ((x * x) + 2.0);
    	} else {
    		tmp = -4.0 / (x * (x * (x * x)));
    	}
    	return tmp;
    }
    
    real(8) function code(x)
        real(8), intent (in) :: x
        real(8) :: tmp
        if (x <= 700.0d0) then
            tmp = 2.0d0 / ((x * x) + 2.0d0)
        else
            tmp = (-4.0d0) / (x * (x * (x * x)))
        end if
        code = tmp
    end function
    
    public static double code(double x) {
    	double tmp;
    	if (x <= 700.0) {
    		tmp = 2.0 / ((x * x) + 2.0);
    	} else {
    		tmp = -4.0 / (x * (x * (x * x)));
    	}
    	return tmp;
    }
    
    def code(x):
    	tmp = 0
    	if x <= 700.0:
    		tmp = 2.0 / ((x * x) + 2.0)
    	else:
    		tmp = -4.0 / (x * (x * (x * x)))
    	return tmp
    
    function code(x)
    	tmp = 0.0
    	if (x <= 700.0)
    		tmp = Float64(2.0 / Float64(Float64(x * x) + 2.0));
    	else
    		tmp = Float64(-4.0 / Float64(x * Float64(x * Float64(x * x))));
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	tmp = 0.0;
    	if (x <= 700.0)
    		tmp = 2.0 / ((x * x) + 2.0);
    	else
    		tmp = -4.0 / (x * (x * (x * x)));
    	end
    	tmp_2 = tmp;
    end
    
    code[x_] := If[LessEqual[x, 700.0], N[(2.0 / N[(N[(x * x), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], N[(-4.0 / N[(x * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \leq 700:\\
    \;\;\;\;\frac{2}{x \cdot x + 2}\\
    
    \mathbf{else}:\\
    \;\;\;\;\frac{-4}{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 < 700

      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-*.f6483.5%

          \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right) \]
      5. Simplified83.5%

        \[\leadsto \frac{2}{\color{blue}{2 + x \cdot x}} \]

      if 700 < 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-*.f6458.2%

          \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right) \]
      5. Simplified58.2%

        \[\leadsto \frac{2}{\color{blue}{2 + x \cdot x}} \]
      6. Step-by-step derivation
        1. flip-+N/A

          \[\leadsto \frac{2}{\frac{2 \cdot 2 - \left(x \cdot x\right) \cdot \left(x \cdot x\right)}{\color{blue}{2 - x \cdot x}}} \]
        2. associate-/r/N/A

          \[\leadsto \frac{2}{2 \cdot 2 - \left(x \cdot x\right) \cdot \left(x \cdot x\right)} \cdot \color{blue}{\left(2 - x \cdot x\right)} \]
        3. associate-*l/N/A

          \[\leadsto \frac{2 \cdot \left(2 - x \cdot x\right)}{\color{blue}{2 \cdot 2 - \left(x \cdot x\right) \cdot \left(x \cdot x\right)}} \]
        4. sub-negN/A

          \[\leadsto \frac{2 \cdot \left(2 + \left(\mathsf{neg}\left(x \cdot x\right)\right)\right)}{2 \cdot \color{blue}{2} - \left(x \cdot x\right) \cdot \left(x \cdot x\right)} \]
        5. distribute-rgt-inN/A

          \[\leadsto \frac{2 \cdot 2 + \left(\mathsf{neg}\left(x \cdot x\right)\right) \cdot 2}{\color{blue}{2 \cdot 2} - \left(x \cdot x\right) \cdot \left(x \cdot x\right)} \]
        6. cancel-sign-sub-invN/A

          \[\leadsto \frac{2 \cdot 2 - \left(x \cdot x\right) \cdot 2}{\color{blue}{2 \cdot 2} - \left(x \cdot x\right) \cdot \left(x \cdot x\right)} \]
        7. /-lowering-/.f64N/A

          \[\leadsto \mathsf{/.f64}\left(\left(2 \cdot 2 - \left(x \cdot x\right) \cdot 2\right), \color{blue}{\left(2 \cdot 2 - \left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)}\right) \]
        8. *-commutativeN/A

          \[\leadsto \mathsf{/.f64}\left(\left(2 \cdot 2 - 2 \cdot \left(x \cdot x\right)\right), \left(2 \cdot \color{blue}{2} - \left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) \]
        9. sub-negN/A

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

          \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\left(2 \cdot 2\right), \left(\mathsf{neg}\left(2 \cdot \left(x \cdot x\right)\right)\right)\right), \left(\color{blue}{2 \cdot 2} - \left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) \]
        11. metadata-evalN/A

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

          \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(4, \left(\mathsf{neg}\left(\left(x \cdot x\right) \cdot 2\right)\right)\right), \left(2 \cdot 2 - \left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) \]
        13. distribute-rgt-neg-inN/A

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

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

          \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(4, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\mathsf{neg}\left(2\right)\right)\right)\right), \left(2 \cdot 2 - \left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) \]
        16. metadata-evalN/A

          \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(4, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), -2\right)\right), \left(2 \cdot 2 - \left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) \]
        17. --lowering--.f64N/A

          \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(4, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), -2\right)\right), \mathsf{\_.f64}\left(\left(2 \cdot 2\right), \color{blue}{\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)}\right)\right) \]
        18. metadata-evalN/A

          \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(4, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), -2\right)\right), \mathsf{\_.f64}\left(4, \left(\color{blue}{\left(x \cdot x\right)} \cdot \left(x \cdot x\right)\right)\right)\right) \]
        19. associate-*l*N/A

          \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(4, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), -2\right)\right), \mathsf{\_.f64}\left(4, \left(x \cdot \color{blue}{\left(x \cdot \left(x \cdot x\right)\right)}\right)\right)\right) \]
        20. cube-unmultN/A

          \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(4, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), -2\right)\right), \mathsf{\_.f64}\left(4, \left(x \cdot {x}^{\color{blue}{3}}\right)\right)\right) \]
      7. Applied egg-rr26.1%

        \[\leadsto \color{blue}{\frac{4 + \left(x \cdot x\right) \cdot -2}{4 - x \cdot \left(x \cdot \left(x \cdot x\right)\right)}} \]
      8. Taylor expanded in x around 0

        \[\leadsto \mathsf{/.f64}\left(\color{blue}{4}, \mathsf{\_.f64}\left(4, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right)\right)\right)\right) \]
      9. Step-by-step derivation
        1. Simplified82.4%

          \[\leadsto \frac{\color{blue}{4}}{4 - x \cdot \left(x \cdot \left(x \cdot x\right)\right)} \]
        2. Taylor expanded in x around inf

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

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

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

            \[\leadsto \mathsf{/.f64}\left(-4, \left({x}^{3} \cdot \color{blue}{x}\right)\right) \]
          4. *-commutativeN/A

            \[\leadsto \mathsf{/.f64}\left(-4, \left(x \cdot \color{blue}{{x}^{3}}\right)\right) \]
          5. *-lowering-*.f64N/A

            \[\leadsto \mathsf{/.f64}\left(-4, \mathsf{*.f64}\left(x, \color{blue}{\left({x}^{3}\right)}\right)\right) \]
          6. cube-multN/A

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

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

            \[\leadsto \mathsf{/.f64}\left(-4, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{\left({x}^{2}\right)}\right)\right)\right) \]
          9. unpow2N/A

            \[\leadsto \mathsf{/.f64}\left(-4, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \left(x \cdot \color{blue}{x}\right)\right)\right)\right) \]
          10. *-lowering-*.f6482.4%

            \[\leadsto \mathsf{/.f64}\left(-4, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right)\right) \]
        4. Simplified82.4%

          \[\leadsto \color{blue}{\frac{-4}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}} \]
      10. Recombined 2 regimes into one program.
      11. Final simplification83.3%

        \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 700:\\ \;\;\;\;\frac{2}{x \cdot x + 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{-4}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\\ \end{array} \]
      12. Add Preprocessing

      Alternative 7: 62.6% accurate, 17.1× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.25:\\ \;\;\;\;1 + x \cdot \left(x \cdot -0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{2}{x \cdot x}\\ \end{array} \end{array} \]
      (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(x * Float64(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[(x * N[(x * -0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(2.0 / N[(x * x), $MachinePrecision]), $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;x \leq 1.25:\\
      \;\;\;\;1 + x \cdot \left(x \cdot -0.5\right)\\
      
      \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. unpow2N/A

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

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

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

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

            \[\leadsto \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \left(x \cdot \color{blue}{\frac{-1}{2}}\right)\right)\right) \]
          7. *-lowering-*.f6466.6%

            \[\leadsto \mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \color{blue}{\frac{-1}{2}}\right)\right)\right) \]
        5. Simplified66.6%

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

        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-*.f6458.2%

            \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right) \]
        5. Simplified58.2%

          \[\leadsto \frac{2}{\color{blue}{2 + x \cdot x}} \]
        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-*.f6458.2%

            \[\leadsto \mathsf{/.f64}\left(2, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right) \]
        8. Simplified58.2%

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

      Alternative 8: 87.2% accurate, 18.7× speedup?

      \[\begin{array}{l} \\ \frac{4}{4 - x \cdot \left(x \cdot \left(x \cdot x\right)\right)} \end{array} \]
      (FPCore (x) :precision binary64 (/ 4.0 (- 4.0 (* x (* x (* x x))))))
      double code(double x) {
      	return 4.0 / (4.0 - (x * (x * (x * x))));
      }
      
      real(8) function code(x)
          real(8), intent (in) :: x
          code = 4.0d0 / (4.0d0 - (x * (x * (x * x))))
      end function
      
      public static double code(double x) {
      	return 4.0 / (4.0 - (x * (x * (x * x))));
      }
      
      def code(x):
      	return 4.0 / (4.0 - (x * (x * (x * x))))
      
      function code(x)
      	return Float64(4.0 / Float64(4.0 - Float64(x * Float64(x * Float64(x * x)))))
      end
      
      function tmp = code(x)
      	tmp = 4.0 / (4.0 - (x * (x * (x * x))));
      end
      
      code[x_] := N[(4.0 / N[(4.0 - N[(x * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \frac{4}{4 - x \cdot \left(x \cdot \left(x \cdot x\right)\right)}
      \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-*.f6477.7%

          \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right) \]
      5. Simplified77.7%

        \[\leadsto \frac{2}{\color{blue}{2 + x \cdot x}} \]
      6. Step-by-step derivation
        1. flip-+N/A

          \[\leadsto \frac{2}{\frac{2 \cdot 2 - \left(x \cdot x\right) \cdot \left(x \cdot x\right)}{\color{blue}{2 - x \cdot x}}} \]
        2. associate-/r/N/A

          \[\leadsto \frac{2}{2 \cdot 2 - \left(x \cdot x\right) \cdot \left(x \cdot x\right)} \cdot \color{blue}{\left(2 - x \cdot x\right)} \]
        3. associate-*l/N/A

          \[\leadsto \frac{2 \cdot \left(2 - x \cdot x\right)}{\color{blue}{2 \cdot 2 - \left(x \cdot x\right) \cdot \left(x \cdot x\right)}} \]
        4. sub-negN/A

          \[\leadsto \frac{2 \cdot \left(2 + \left(\mathsf{neg}\left(x \cdot x\right)\right)\right)}{2 \cdot \color{blue}{2} - \left(x \cdot x\right) \cdot \left(x \cdot x\right)} \]
        5. distribute-rgt-inN/A

          \[\leadsto \frac{2 \cdot 2 + \left(\mathsf{neg}\left(x \cdot x\right)\right) \cdot 2}{\color{blue}{2 \cdot 2} - \left(x \cdot x\right) \cdot \left(x \cdot x\right)} \]
        6. cancel-sign-sub-invN/A

          \[\leadsto \frac{2 \cdot 2 - \left(x \cdot x\right) \cdot 2}{\color{blue}{2 \cdot 2} - \left(x \cdot x\right) \cdot \left(x \cdot x\right)} \]
        7. /-lowering-/.f64N/A

          \[\leadsto \mathsf{/.f64}\left(\left(2 \cdot 2 - \left(x \cdot x\right) \cdot 2\right), \color{blue}{\left(2 \cdot 2 - \left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)}\right) \]
        8. *-commutativeN/A

          \[\leadsto \mathsf{/.f64}\left(\left(2 \cdot 2 - 2 \cdot \left(x \cdot x\right)\right), \left(2 \cdot \color{blue}{2} - \left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) \]
        9. sub-negN/A

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

          \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\left(2 \cdot 2\right), \left(\mathsf{neg}\left(2 \cdot \left(x \cdot x\right)\right)\right)\right), \left(\color{blue}{2 \cdot 2} - \left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) \]
        11. metadata-evalN/A

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

          \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(4, \left(\mathsf{neg}\left(\left(x \cdot x\right) \cdot 2\right)\right)\right), \left(2 \cdot 2 - \left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) \]
        13. distribute-rgt-neg-inN/A

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

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

          \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(4, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\mathsf{neg}\left(2\right)\right)\right)\right), \left(2 \cdot 2 - \left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) \]
        16. metadata-evalN/A

          \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(4, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), -2\right)\right), \left(2 \cdot 2 - \left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) \]
        17. --lowering--.f64N/A

          \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(4, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), -2\right)\right), \mathsf{\_.f64}\left(\left(2 \cdot 2\right), \color{blue}{\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)}\right)\right) \]
        18. metadata-evalN/A

          \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(4, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), -2\right)\right), \mathsf{\_.f64}\left(4, \left(\color{blue}{\left(x \cdot x\right)} \cdot \left(x \cdot x\right)\right)\right)\right) \]
        19. associate-*l*N/A

          \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(4, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), -2\right)\right), \mathsf{\_.f64}\left(4, \left(x \cdot \color{blue}{\left(x \cdot \left(x \cdot x\right)\right)}\right)\right)\right) \]
        20. cube-unmultN/A

          \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(4, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), -2\right)\right), \mathsf{\_.f64}\left(4, \left(x \cdot {x}^{\color{blue}{3}}\right)\right)\right) \]
      7. Applied egg-rr63.3%

        \[\leadsto \color{blue}{\frac{4 + \left(x \cdot x\right) \cdot -2}{4 - x \cdot \left(x \cdot \left(x \cdot x\right)\right)}} \]
      8. Taylor expanded in x around 0

        \[\leadsto \mathsf{/.f64}\left(\color{blue}{4}, \mathsf{\_.f64}\left(4, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, x\right)\right)\right)\right)\right) \]
      9. Step-by-step derivation
        1. Simplified88.9%

          \[\leadsto \frac{\color{blue}{4}}{4 - x \cdot \left(x \cdot \left(x \cdot x\right)\right)} \]
        2. Add Preprocessing

        Alternative 9: 62.6% 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. Simplified66.6%

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

            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-*.f6458.2%

                \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right) \]
            5. Simplified58.2%

              \[\leadsto \frac{2}{\color{blue}{2 + x \cdot x}} \]
            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-*.f6458.2%

                \[\leadsto \mathsf{/.f64}\left(2, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right) \]
            8. Simplified58.2%

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

          Alternative 10: 75.8% 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-*.f6477.7%

              \[\leadsto \mathsf{/.f64}\left(2, \mathsf{+.f64}\left(2, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right) \]
          5. Simplified77.7%

            \[\leadsto \frac{2}{\color{blue}{2 + x \cdot x}} \]
          6. Final simplification77.7%

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

          Alternative 11: 50.4% 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. Simplified52.0%

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

            Reproduce

            ?
            herbie shell --seed 2024155 
            (FPCore (x)
              :name "Hyperbolic secant"
              :precision binary64
              (/ 2.0 (+ (exp x) (exp (- x)))))