subtraction fraction

Percentage Accurate: 100.0% → 100.0%
Time: 3.2s
Alternatives: 5
Speedup: 1.1×

Specification

?
\[\begin{array}{l} \\ \frac{-\left(f + n\right)}{f - n} \end{array} \]
(FPCore (f n) :precision binary64 (/ (- (+ f n)) (- f n)))
double code(double f, double n) {
	return -(f + n) / (f - n);
}
real(8) function code(f, n)
    real(8), intent (in) :: f
    real(8), intent (in) :: n
    code = -(f + n) / (f - n)
end function
public static double code(double f, double n) {
	return -(f + n) / (f - n);
}
def code(f, n):
	return -(f + n) / (f - n)
function code(f, n)
	return Float64(Float64(-Float64(f + n)) / Float64(f - n))
end
function tmp = code(f, n)
	tmp = -(f + n) / (f - n);
end
code[f_, n_] := N[((-N[(f + n), $MachinePrecision]) / N[(f - n), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-\left(f + n\right)}{f - n}
\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 5 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?

\[\begin{array}{l} \\ \frac{-\left(f + n\right)}{f - n} \end{array} \]
(FPCore (f n) :precision binary64 (/ (- (+ f n)) (- f n)))
double code(double f, double n) {
	return -(f + n) / (f - n);
}
real(8) function code(f, n)
    real(8), intent (in) :: f
    real(8), intent (in) :: n
    code = -(f + n) / (f - n)
end function
public static double code(double f, double n) {
	return -(f + n) / (f - n);
}
def code(f, n):
	return -(f + n) / (f - n)
function code(f, n)
	return Float64(Float64(-Float64(f + n)) / Float64(f - n))
end
function tmp = code(f, n)
	tmp = -(f + n) / (f - n);
end
code[f_, n_] := N[((-N[(f + n), $MachinePrecision]) / N[(f - n), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-\left(f + n\right)}{f - n}
\end{array}

Alternative 1: 100.0% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \frac{f + n}{n - f} \end{array} \]
(FPCore (f n) :precision binary64 (/ (+ f n) (- n f)))
double code(double f, double n) {
	return (f + n) / (n - f);
}
real(8) function code(f, n)
    real(8), intent (in) :: f
    real(8), intent (in) :: n
    code = (f + n) / (n - f)
end function
public static double code(double f, double n) {
	return (f + n) / (n - f);
}
def code(f, n):
	return (f + n) / (n - f)
function code(f, n)
	return Float64(Float64(f + n) / Float64(n - f))
end
function tmp = code(f, n)
	tmp = (f + n) / (n - f);
end
code[f_, n_] := N[(N[(f + n), $MachinePrecision] / N[(n - f), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{f + n}{n - f}
\end{array}
Derivation
  1. Initial program 99.9%

    \[\frac{-\left(f + n\right)}{f - n} \]
  2. Step-by-step derivation
    1. /-rgt-identity99.9%

      \[\leadsto \frac{\color{blue}{\frac{-\left(f + n\right)}{1}}}{f - n} \]
    2. metadata-eval99.9%

      \[\leadsto \frac{\frac{-\left(f + n\right)}{\color{blue}{\frac{-1}{-1}}}}{f - n} \]
    3. neg-mul-199.9%

      \[\leadsto \frac{\frac{\color{blue}{-1 \cdot \left(f + n\right)}}{\frac{-1}{-1}}}{f - n} \]
    4. *-commutative99.9%

      \[\leadsto \frac{\frac{\color{blue}{\left(f + n\right) \cdot -1}}{\frac{-1}{-1}}}{f - n} \]
    5. associate-/l*99.9%

      \[\leadsto \frac{\color{blue}{\frac{f + n}{\frac{\frac{-1}{-1}}{-1}}}}{f - n} \]
    6. metadata-eval99.9%

      \[\leadsto \frac{\frac{f + n}{\frac{\color{blue}{1}}{-1}}}{f - n} \]
    7. metadata-eval99.9%

      \[\leadsto \frac{\frac{f + n}{\color{blue}{-1}}}{f - n} \]
    8. associate-/r*99.9%

      \[\leadsto \color{blue}{\frac{f + n}{-1 \cdot \left(f - n\right)}} \]
    9. neg-mul-199.9%

      \[\leadsto \frac{f + n}{\color{blue}{-\left(f - n\right)}} \]
    10. sub-neg99.9%

      \[\leadsto \frac{f + n}{-\color{blue}{\left(f + \left(-n\right)\right)}} \]
    11. +-commutative99.9%

      \[\leadsto \frac{f + n}{-\color{blue}{\left(\left(-n\right) + f\right)}} \]
    12. distribute-neg-in99.9%

      \[\leadsto \frac{f + n}{\color{blue}{\left(-\left(-n\right)\right) + \left(-f\right)}} \]
    13. remove-double-neg99.9%

      \[\leadsto \frac{f + n}{\color{blue}{n} + \left(-f\right)} \]
    14. sub-neg99.9%

      \[\leadsto \frac{f + n}{\color{blue}{n - f}} \]
  3. Simplified99.9%

    \[\leadsto \color{blue}{\frac{f + n}{n - f}} \]
  4. Add Preprocessing
  5. Final simplification99.9%

    \[\leadsto \frac{f + n}{n - f} \]
  6. Add Preprocessing

Alternative 2: 72.8% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 1 + 2 \cdot \frac{f}{n}\\ \mathbf{if}\;n \leq -2.9 \cdot 10^{+125}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;n \leq -6.4 \cdot 10^{+113}:\\ \;\;\;\;-1\\ \mathbf{elif}\;n \leq -3.6 \cdot 10^{-37}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;n \leq 9.2 \cdot 10^{+40}:\\ \;\;\;\;-1\\ \mathbf{elif}\;n \leq 4 \cdot 10^{+65}:\\ \;\;\;\;1\\ \mathbf{elif}\;n \leq 5.6 \cdot 10^{+135}:\\ \;\;\;\;-1\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (f n)
 :precision binary64
 (let* ((t_0 (+ 1.0 (* 2.0 (/ f n)))))
   (if (<= n -2.9e+125)
     t_0
     (if (<= n -6.4e+113)
       -1.0
       (if (<= n -3.6e-37)
         t_0
         (if (<= n 9.2e+40)
           -1.0
           (if (<= n 4e+65) 1.0 (if (<= n 5.6e+135) -1.0 t_0))))))))
double code(double f, double n) {
	double t_0 = 1.0 + (2.0 * (f / n));
	double tmp;
	if (n <= -2.9e+125) {
		tmp = t_0;
	} else if (n <= -6.4e+113) {
		tmp = -1.0;
	} else if (n <= -3.6e-37) {
		tmp = t_0;
	} else if (n <= 9.2e+40) {
		tmp = -1.0;
	} else if (n <= 4e+65) {
		tmp = 1.0;
	} else if (n <= 5.6e+135) {
		tmp = -1.0;
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(f, n)
    real(8), intent (in) :: f
    real(8), intent (in) :: n
    real(8) :: t_0
    real(8) :: tmp
    t_0 = 1.0d0 + (2.0d0 * (f / n))
    if (n <= (-2.9d+125)) then
        tmp = t_0
    else if (n <= (-6.4d+113)) then
        tmp = -1.0d0
    else if (n <= (-3.6d-37)) then
        tmp = t_0
    else if (n <= 9.2d+40) then
        tmp = -1.0d0
    else if (n <= 4d+65) then
        tmp = 1.0d0
    else if (n <= 5.6d+135) then
        tmp = -1.0d0
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double f, double n) {
	double t_0 = 1.0 + (2.0 * (f / n));
	double tmp;
	if (n <= -2.9e+125) {
		tmp = t_0;
	} else if (n <= -6.4e+113) {
		tmp = -1.0;
	} else if (n <= -3.6e-37) {
		tmp = t_0;
	} else if (n <= 9.2e+40) {
		tmp = -1.0;
	} else if (n <= 4e+65) {
		tmp = 1.0;
	} else if (n <= 5.6e+135) {
		tmp = -1.0;
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(f, n):
	t_0 = 1.0 + (2.0 * (f / n))
	tmp = 0
	if n <= -2.9e+125:
		tmp = t_0
	elif n <= -6.4e+113:
		tmp = -1.0
	elif n <= -3.6e-37:
		tmp = t_0
	elif n <= 9.2e+40:
		tmp = -1.0
	elif n <= 4e+65:
		tmp = 1.0
	elif n <= 5.6e+135:
		tmp = -1.0
	else:
		tmp = t_0
	return tmp
function code(f, n)
	t_0 = Float64(1.0 + Float64(2.0 * Float64(f / n)))
	tmp = 0.0
	if (n <= -2.9e+125)
		tmp = t_0;
	elseif (n <= -6.4e+113)
		tmp = -1.0;
	elseif (n <= -3.6e-37)
		tmp = t_0;
	elseif (n <= 9.2e+40)
		tmp = -1.0;
	elseif (n <= 4e+65)
		tmp = 1.0;
	elseif (n <= 5.6e+135)
		tmp = -1.0;
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(f, n)
	t_0 = 1.0 + (2.0 * (f / n));
	tmp = 0.0;
	if (n <= -2.9e+125)
		tmp = t_0;
	elseif (n <= -6.4e+113)
		tmp = -1.0;
	elseif (n <= -3.6e-37)
		tmp = t_0;
	elseif (n <= 9.2e+40)
		tmp = -1.0;
	elseif (n <= 4e+65)
		tmp = 1.0;
	elseif (n <= 5.6e+135)
		tmp = -1.0;
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[f_, n_] := Block[{t$95$0 = N[(1.0 + N[(2.0 * N[(f / n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[n, -2.9e+125], t$95$0, If[LessEqual[n, -6.4e+113], -1.0, If[LessEqual[n, -3.6e-37], t$95$0, If[LessEqual[n, 9.2e+40], -1.0, If[LessEqual[n, 4e+65], 1.0, If[LessEqual[n, 5.6e+135], -1.0, t$95$0]]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := 1 + 2 \cdot \frac{f}{n}\\
\mathbf{if}\;n \leq -2.9 \cdot 10^{+125}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;n \leq -6.4 \cdot 10^{+113}:\\
\;\;\;\;-1\\

\mathbf{elif}\;n \leq -3.6 \cdot 10^{-37}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;n \leq 9.2 \cdot 10^{+40}:\\
\;\;\;\;-1\\

\mathbf{elif}\;n \leq 4 \cdot 10^{+65}:\\
\;\;\;\;1\\

\mathbf{elif}\;n \leq 5.6 \cdot 10^{+135}:\\
\;\;\;\;-1\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if n < -2.89999999999999993e125 or -6.3999999999999996e113 < n < -3.60000000000000007e-37 or 5.60000000000000004e135 < n

    1. Initial program 99.9%

      \[\frac{-\left(f + n\right)}{f - n} \]
    2. Step-by-step derivation
      1. /-rgt-identity99.9%

        \[\leadsto \frac{\color{blue}{\frac{-\left(f + n\right)}{1}}}{f - n} \]
      2. metadata-eval99.9%

        \[\leadsto \frac{\frac{-\left(f + n\right)}{\color{blue}{\frac{-1}{-1}}}}{f - n} \]
      3. neg-mul-199.9%

        \[\leadsto \frac{\frac{\color{blue}{-1 \cdot \left(f + n\right)}}{\frac{-1}{-1}}}{f - n} \]
      4. *-commutative99.9%

        \[\leadsto \frac{\frac{\color{blue}{\left(f + n\right) \cdot -1}}{\frac{-1}{-1}}}{f - n} \]
      5. associate-/l*99.9%

        \[\leadsto \frac{\color{blue}{\frac{f + n}{\frac{\frac{-1}{-1}}{-1}}}}{f - n} \]
      6. metadata-eval99.9%

        \[\leadsto \frac{\frac{f + n}{\frac{\color{blue}{1}}{-1}}}{f - n} \]
      7. metadata-eval99.9%

        \[\leadsto \frac{\frac{f + n}{\color{blue}{-1}}}{f - n} \]
      8. associate-/r*99.9%

        \[\leadsto \color{blue}{\frac{f + n}{-1 \cdot \left(f - n\right)}} \]
      9. neg-mul-199.9%

        \[\leadsto \frac{f + n}{\color{blue}{-\left(f - n\right)}} \]
      10. sub-neg99.9%

        \[\leadsto \frac{f + n}{-\color{blue}{\left(f + \left(-n\right)\right)}} \]
      11. +-commutative99.9%

        \[\leadsto \frac{f + n}{-\color{blue}{\left(\left(-n\right) + f\right)}} \]
      12. distribute-neg-in99.9%

        \[\leadsto \frac{f + n}{\color{blue}{\left(-\left(-n\right)\right) + \left(-f\right)}} \]
      13. remove-double-neg99.9%

        \[\leadsto \frac{f + n}{\color{blue}{n} + \left(-f\right)} \]
      14. sub-neg99.9%

        \[\leadsto \frac{f + n}{\color{blue}{n - f}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{f + n}{n - f}} \]
    4. Add Preprocessing
    5. Taylor expanded in f around 0 87.4%

      \[\leadsto \color{blue}{1 + 2 \cdot \frac{f}{n}} \]

    if -2.89999999999999993e125 < n < -6.3999999999999996e113 or -3.60000000000000007e-37 < n < 9.19999999999999975e40 or 4e65 < n < 5.60000000000000004e135

    1. Initial program 99.9%

      \[\frac{-\left(f + n\right)}{f - n} \]
    2. Step-by-step derivation
      1. /-rgt-identity99.9%

        \[\leadsto \frac{\color{blue}{\frac{-\left(f + n\right)}{1}}}{f - n} \]
      2. metadata-eval99.9%

        \[\leadsto \frac{\frac{-\left(f + n\right)}{\color{blue}{\frac{-1}{-1}}}}{f - n} \]
      3. neg-mul-199.9%

        \[\leadsto \frac{\frac{\color{blue}{-1 \cdot \left(f + n\right)}}{\frac{-1}{-1}}}{f - n} \]
      4. *-commutative99.9%

        \[\leadsto \frac{\frac{\color{blue}{\left(f + n\right) \cdot -1}}{\frac{-1}{-1}}}{f - n} \]
      5. associate-/l*99.9%

        \[\leadsto \frac{\color{blue}{\frac{f + n}{\frac{\frac{-1}{-1}}{-1}}}}{f - n} \]
      6. metadata-eval99.9%

        \[\leadsto \frac{\frac{f + n}{\frac{\color{blue}{1}}{-1}}}{f - n} \]
      7. metadata-eval99.9%

        \[\leadsto \frac{\frac{f + n}{\color{blue}{-1}}}{f - n} \]
      8. associate-/r*99.9%

        \[\leadsto \color{blue}{\frac{f + n}{-1 \cdot \left(f - n\right)}} \]
      9. neg-mul-199.9%

        \[\leadsto \frac{f + n}{\color{blue}{-\left(f - n\right)}} \]
      10. sub-neg99.9%

        \[\leadsto \frac{f + n}{-\color{blue}{\left(f + \left(-n\right)\right)}} \]
      11. +-commutative99.9%

        \[\leadsto \frac{f + n}{-\color{blue}{\left(\left(-n\right) + f\right)}} \]
      12. distribute-neg-in99.9%

        \[\leadsto \frac{f + n}{\color{blue}{\left(-\left(-n\right)\right) + \left(-f\right)}} \]
      13. remove-double-neg99.9%

        \[\leadsto \frac{f + n}{\color{blue}{n} + \left(-f\right)} \]
      14. sub-neg99.9%

        \[\leadsto \frac{f + n}{\color{blue}{n - f}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{f + n}{n - f}} \]
    4. Add Preprocessing
    5. Taylor expanded in f around inf 82.1%

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

    if 9.19999999999999975e40 < n < 4e65

    1. Initial program 100.0%

      \[\frac{-\left(f + n\right)}{f - n} \]
    2. Step-by-step derivation
      1. /-rgt-identity100.0%

        \[\leadsto \frac{\color{blue}{\frac{-\left(f + n\right)}{1}}}{f - n} \]
      2. metadata-eval100.0%

        \[\leadsto \frac{\frac{-\left(f + n\right)}{\color{blue}{\frac{-1}{-1}}}}{f - n} \]
      3. neg-mul-1100.0%

        \[\leadsto \frac{\frac{\color{blue}{-1 \cdot \left(f + n\right)}}{\frac{-1}{-1}}}{f - n} \]
      4. *-commutative100.0%

        \[\leadsto \frac{\frac{\color{blue}{\left(f + n\right) \cdot -1}}{\frac{-1}{-1}}}{f - n} \]
      5. associate-/l*100.0%

        \[\leadsto \frac{\color{blue}{\frac{f + n}{\frac{\frac{-1}{-1}}{-1}}}}{f - n} \]
      6. metadata-eval100.0%

        \[\leadsto \frac{\frac{f + n}{\frac{\color{blue}{1}}{-1}}}{f - n} \]
      7. metadata-eval100.0%

        \[\leadsto \frac{\frac{f + n}{\color{blue}{-1}}}{f - n} \]
      8. associate-/r*100.0%

        \[\leadsto \color{blue}{\frac{f + n}{-1 \cdot \left(f - n\right)}} \]
      9. neg-mul-1100.0%

        \[\leadsto \frac{f + n}{\color{blue}{-\left(f - n\right)}} \]
      10. sub-neg100.0%

        \[\leadsto \frac{f + n}{-\color{blue}{\left(f + \left(-n\right)\right)}} \]
      11. +-commutative100.0%

        \[\leadsto \frac{f + n}{-\color{blue}{\left(\left(-n\right) + f\right)}} \]
      12. distribute-neg-in100.0%

        \[\leadsto \frac{f + n}{\color{blue}{\left(-\left(-n\right)\right) + \left(-f\right)}} \]
      13. remove-double-neg100.0%

        \[\leadsto \frac{f + n}{\color{blue}{n} + \left(-f\right)} \]
      14. sub-neg100.0%

        \[\leadsto \frac{f + n}{\color{blue}{n - f}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{f + n}{n - f}} \]
    4. Add Preprocessing
    5. Taylor expanded in f around 0 100.0%

      \[\leadsto \color{blue}{1} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification84.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;n \leq -2.9 \cdot 10^{+125}:\\ \;\;\;\;1 + 2 \cdot \frac{f}{n}\\ \mathbf{elif}\;n \leq -6.4 \cdot 10^{+113}:\\ \;\;\;\;-1\\ \mathbf{elif}\;n \leq -3.6 \cdot 10^{-37}:\\ \;\;\;\;1 + 2 \cdot \frac{f}{n}\\ \mathbf{elif}\;n \leq 9.2 \cdot 10^{+40}:\\ \;\;\;\;-1\\ \mathbf{elif}\;n \leq 4 \cdot 10^{+65}:\\ \;\;\;\;1\\ \mathbf{elif}\;n \leq 5.6 \cdot 10^{+135}:\\ \;\;\;\;-1\\ \mathbf{else}:\\ \;\;\;\;1 + 2 \cdot \frac{f}{n}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 73.9% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 1 + 2 \cdot \frac{f}{n}\\ t_1 := -2 \cdot \frac{n}{f} + -1\\ \mathbf{if}\;n \leq -1.25 \cdot 10^{+124}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;n \leq -6.4 \cdot 10^{+113}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;n \leq -28000000000000:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;n \leq 1.95 \cdot 10^{+42}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;n \leq 1.45 \cdot 10^{+70}:\\ \;\;\;\;1\\ \mathbf{elif}\;n \leq 1.65 \cdot 10^{+131}:\\ \;\;\;\;t\_1\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (f n)
 :precision binary64
 (let* ((t_0 (+ 1.0 (* 2.0 (/ f n)))) (t_1 (+ (* -2.0 (/ n f)) -1.0)))
   (if (<= n -1.25e+124)
     t_0
     (if (<= n -6.4e+113)
       t_1
       (if (<= n -28000000000000.0)
         t_0
         (if (<= n 1.95e+42)
           t_1
           (if (<= n 1.45e+70) 1.0 (if (<= n 1.65e+131) t_1 t_0))))))))
double code(double f, double n) {
	double t_0 = 1.0 + (2.0 * (f / n));
	double t_1 = (-2.0 * (n / f)) + -1.0;
	double tmp;
	if (n <= -1.25e+124) {
		tmp = t_0;
	} else if (n <= -6.4e+113) {
		tmp = t_1;
	} else if (n <= -28000000000000.0) {
		tmp = t_0;
	} else if (n <= 1.95e+42) {
		tmp = t_1;
	} else if (n <= 1.45e+70) {
		tmp = 1.0;
	} else if (n <= 1.65e+131) {
		tmp = t_1;
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(f, n)
    real(8), intent (in) :: f
    real(8), intent (in) :: n
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = 1.0d0 + (2.0d0 * (f / n))
    t_1 = ((-2.0d0) * (n / f)) + (-1.0d0)
    if (n <= (-1.25d+124)) then
        tmp = t_0
    else if (n <= (-6.4d+113)) then
        tmp = t_1
    else if (n <= (-28000000000000.0d0)) then
        tmp = t_0
    else if (n <= 1.95d+42) then
        tmp = t_1
    else if (n <= 1.45d+70) then
        tmp = 1.0d0
    else if (n <= 1.65d+131) then
        tmp = t_1
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double f, double n) {
	double t_0 = 1.0 + (2.0 * (f / n));
	double t_1 = (-2.0 * (n / f)) + -1.0;
	double tmp;
	if (n <= -1.25e+124) {
		tmp = t_0;
	} else if (n <= -6.4e+113) {
		tmp = t_1;
	} else if (n <= -28000000000000.0) {
		tmp = t_0;
	} else if (n <= 1.95e+42) {
		tmp = t_1;
	} else if (n <= 1.45e+70) {
		tmp = 1.0;
	} else if (n <= 1.65e+131) {
		tmp = t_1;
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(f, n):
	t_0 = 1.0 + (2.0 * (f / n))
	t_1 = (-2.0 * (n / f)) + -1.0
	tmp = 0
	if n <= -1.25e+124:
		tmp = t_0
	elif n <= -6.4e+113:
		tmp = t_1
	elif n <= -28000000000000.0:
		tmp = t_0
	elif n <= 1.95e+42:
		tmp = t_1
	elif n <= 1.45e+70:
		tmp = 1.0
	elif n <= 1.65e+131:
		tmp = t_1
	else:
		tmp = t_0
	return tmp
function code(f, n)
	t_0 = Float64(1.0 + Float64(2.0 * Float64(f / n)))
	t_1 = Float64(Float64(-2.0 * Float64(n / f)) + -1.0)
	tmp = 0.0
	if (n <= -1.25e+124)
		tmp = t_0;
	elseif (n <= -6.4e+113)
		tmp = t_1;
	elseif (n <= -28000000000000.0)
		tmp = t_0;
	elseif (n <= 1.95e+42)
		tmp = t_1;
	elseif (n <= 1.45e+70)
		tmp = 1.0;
	elseif (n <= 1.65e+131)
		tmp = t_1;
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(f, n)
	t_0 = 1.0 + (2.0 * (f / n));
	t_1 = (-2.0 * (n / f)) + -1.0;
	tmp = 0.0;
	if (n <= -1.25e+124)
		tmp = t_0;
	elseif (n <= -6.4e+113)
		tmp = t_1;
	elseif (n <= -28000000000000.0)
		tmp = t_0;
	elseif (n <= 1.95e+42)
		tmp = t_1;
	elseif (n <= 1.45e+70)
		tmp = 1.0;
	elseif (n <= 1.65e+131)
		tmp = t_1;
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[f_, n_] := Block[{t$95$0 = N[(1.0 + N[(2.0 * N[(f / n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(-2.0 * N[(n / f), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]}, If[LessEqual[n, -1.25e+124], t$95$0, If[LessEqual[n, -6.4e+113], t$95$1, If[LessEqual[n, -28000000000000.0], t$95$0, If[LessEqual[n, 1.95e+42], t$95$1, If[LessEqual[n, 1.45e+70], 1.0, If[LessEqual[n, 1.65e+131], t$95$1, t$95$0]]]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := 1 + 2 \cdot \frac{f}{n}\\
t_1 := -2 \cdot \frac{n}{f} + -1\\
\mathbf{if}\;n \leq -1.25 \cdot 10^{+124}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;n \leq -6.4 \cdot 10^{+113}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;n \leq -28000000000000:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;n \leq 1.95 \cdot 10^{+42}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;n \leq 1.45 \cdot 10^{+70}:\\
\;\;\;\;1\\

\mathbf{elif}\;n \leq 1.65 \cdot 10^{+131}:\\
\;\;\;\;t\_1\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if n < -1.2499999999999999e124 or -6.3999999999999996e113 < n < -2.8e13 or 1.6499999999999999e131 < n

    1. Initial program 99.9%

      \[\frac{-\left(f + n\right)}{f - n} \]
    2. Step-by-step derivation
      1. /-rgt-identity99.9%

        \[\leadsto \frac{\color{blue}{\frac{-\left(f + n\right)}{1}}}{f - n} \]
      2. metadata-eval99.9%

        \[\leadsto \frac{\frac{-\left(f + n\right)}{\color{blue}{\frac{-1}{-1}}}}{f - n} \]
      3. neg-mul-199.9%

        \[\leadsto \frac{\frac{\color{blue}{-1 \cdot \left(f + n\right)}}{\frac{-1}{-1}}}{f - n} \]
      4. *-commutative99.9%

        \[\leadsto \frac{\frac{\color{blue}{\left(f + n\right) \cdot -1}}{\frac{-1}{-1}}}{f - n} \]
      5. associate-/l*99.9%

        \[\leadsto \frac{\color{blue}{\frac{f + n}{\frac{\frac{-1}{-1}}{-1}}}}{f - n} \]
      6. metadata-eval99.9%

        \[\leadsto \frac{\frac{f + n}{\frac{\color{blue}{1}}{-1}}}{f - n} \]
      7. metadata-eval99.9%

        \[\leadsto \frac{\frac{f + n}{\color{blue}{-1}}}{f - n} \]
      8. associate-/r*99.9%

        \[\leadsto \color{blue}{\frac{f + n}{-1 \cdot \left(f - n\right)}} \]
      9. neg-mul-199.9%

        \[\leadsto \frac{f + n}{\color{blue}{-\left(f - n\right)}} \]
      10. sub-neg99.9%

        \[\leadsto \frac{f + n}{-\color{blue}{\left(f + \left(-n\right)\right)}} \]
      11. +-commutative99.9%

        \[\leadsto \frac{f + n}{-\color{blue}{\left(\left(-n\right) + f\right)}} \]
      12. distribute-neg-in99.9%

        \[\leadsto \frac{f + n}{\color{blue}{\left(-\left(-n\right)\right) + \left(-f\right)}} \]
      13. remove-double-neg99.9%

        \[\leadsto \frac{f + n}{\color{blue}{n} + \left(-f\right)} \]
      14. sub-neg99.9%

        \[\leadsto \frac{f + n}{\color{blue}{n - f}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{f + n}{n - f}} \]
    4. Add Preprocessing
    5. Taylor expanded in f around 0 89.4%

      \[\leadsto \color{blue}{1 + 2 \cdot \frac{f}{n}} \]

    if -1.2499999999999999e124 < n < -6.3999999999999996e113 or -2.8e13 < n < 1.94999999999999985e42 or 1.4499999999999999e70 < n < 1.6499999999999999e131

    1. Initial program 99.9%

      \[\frac{-\left(f + n\right)}{f - n} \]
    2. Step-by-step derivation
      1. /-rgt-identity99.9%

        \[\leadsto \frac{\color{blue}{\frac{-\left(f + n\right)}{1}}}{f - n} \]
      2. metadata-eval99.9%

        \[\leadsto \frac{\frac{-\left(f + n\right)}{\color{blue}{\frac{-1}{-1}}}}{f - n} \]
      3. neg-mul-199.9%

        \[\leadsto \frac{\frac{\color{blue}{-1 \cdot \left(f + n\right)}}{\frac{-1}{-1}}}{f - n} \]
      4. *-commutative99.9%

        \[\leadsto \frac{\frac{\color{blue}{\left(f + n\right) \cdot -1}}{\frac{-1}{-1}}}{f - n} \]
      5. associate-/l*99.9%

        \[\leadsto \frac{\color{blue}{\frac{f + n}{\frac{\frac{-1}{-1}}{-1}}}}{f - n} \]
      6. metadata-eval99.9%

        \[\leadsto \frac{\frac{f + n}{\frac{\color{blue}{1}}{-1}}}{f - n} \]
      7. metadata-eval99.9%

        \[\leadsto \frac{\frac{f + n}{\color{blue}{-1}}}{f - n} \]
      8. associate-/r*99.9%

        \[\leadsto \color{blue}{\frac{f + n}{-1 \cdot \left(f - n\right)}} \]
      9. neg-mul-199.9%

        \[\leadsto \frac{f + n}{\color{blue}{-\left(f - n\right)}} \]
      10. sub-neg99.9%

        \[\leadsto \frac{f + n}{-\color{blue}{\left(f + \left(-n\right)\right)}} \]
      11. +-commutative99.9%

        \[\leadsto \frac{f + n}{-\color{blue}{\left(\left(-n\right) + f\right)}} \]
      12. distribute-neg-in99.9%

        \[\leadsto \frac{f + n}{\color{blue}{\left(-\left(-n\right)\right) + \left(-f\right)}} \]
      13. remove-double-neg99.9%

        \[\leadsto \frac{f + n}{\color{blue}{n} + \left(-f\right)} \]
      14. sub-neg99.9%

        \[\leadsto \frac{f + n}{\color{blue}{n - f}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{f + n}{n - f}} \]
    4. Add Preprocessing
    5. Taylor expanded in n around 0 82.2%

      \[\leadsto \color{blue}{-2 \cdot \frac{n}{f} - 1} \]

    if 1.94999999999999985e42 < n < 1.4499999999999999e70

    1. Initial program 100.0%

      \[\frac{-\left(f + n\right)}{f - n} \]
    2. Step-by-step derivation
      1. /-rgt-identity100.0%

        \[\leadsto \frac{\color{blue}{\frac{-\left(f + n\right)}{1}}}{f - n} \]
      2. metadata-eval100.0%

        \[\leadsto \frac{\frac{-\left(f + n\right)}{\color{blue}{\frac{-1}{-1}}}}{f - n} \]
      3. neg-mul-1100.0%

        \[\leadsto \frac{\frac{\color{blue}{-1 \cdot \left(f + n\right)}}{\frac{-1}{-1}}}{f - n} \]
      4. *-commutative100.0%

        \[\leadsto \frac{\frac{\color{blue}{\left(f + n\right) \cdot -1}}{\frac{-1}{-1}}}{f - n} \]
      5. associate-/l*100.0%

        \[\leadsto \frac{\color{blue}{\frac{f + n}{\frac{\frac{-1}{-1}}{-1}}}}{f - n} \]
      6. metadata-eval100.0%

        \[\leadsto \frac{\frac{f + n}{\frac{\color{blue}{1}}{-1}}}{f - n} \]
      7. metadata-eval100.0%

        \[\leadsto \frac{\frac{f + n}{\color{blue}{-1}}}{f - n} \]
      8. associate-/r*100.0%

        \[\leadsto \color{blue}{\frac{f + n}{-1 \cdot \left(f - n\right)}} \]
      9. neg-mul-1100.0%

        \[\leadsto \frac{f + n}{\color{blue}{-\left(f - n\right)}} \]
      10. sub-neg100.0%

        \[\leadsto \frac{f + n}{-\color{blue}{\left(f + \left(-n\right)\right)}} \]
      11. +-commutative100.0%

        \[\leadsto \frac{f + n}{-\color{blue}{\left(\left(-n\right) + f\right)}} \]
      12. distribute-neg-in100.0%

        \[\leadsto \frac{f + n}{\color{blue}{\left(-\left(-n\right)\right) + \left(-f\right)}} \]
      13. remove-double-neg100.0%

        \[\leadsto \frac{f + n}{\color{blue}{n} + \left(-f\right)} \]
      14. sub-neg100.0%

        \[\leadsto \frac{f + n}{\color{blue}{n - f}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{f + n}{n - f}} \]
    4. Add Preprocessing
    5. Taylor expanded in f around 0 100.0%

      \[\leadsto \color{blue}{1} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification85.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;n \leq -1.25 \cdot 10^{+124}:\\ \;\;\;\;1 + 2 \cdot \frac{f}{n}\\ \mathbf{elif}\;n \leq -6.4 \cdot 10^{+113}:\\ \;\;\;\;-2 \cdot \frac{n}{f} + -1\\ \mathbf{elif}\;n \leq -28000000000000:\\ \;\;\;\;1 + 2 \cdot \frac{f}{n}\\ \mathbf{elif}\;n \leq 1.95 \cdot 10^{+42}:\\ \;\;\;\;-2 \cdot \frac{n}{f} + -1\\ \mathbf{elif}\;n \leq 1.45 \cdot 10^{+70}:\\ \;\;\;\;1\\ \mathbf{elif}\;n \leq 1.65 \cdot 10^{+131}:\\ \;\;\;\;-2 \cdot \frac{n}{f} + -1\\ \mathbf{else}:\\ \;\;\;\;1 + 2 \cdot \frac{f}{n}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 72.7% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;n \leq -1.25 \cdot 10^{+124}:\\ \;\;\;\;1\\ \mathbf{elif}\;n \leq -5 \cdot 10^{+111}:\\ \;\;\;\;-1\\ \mathbf{elif}\;n \leq -3.6 \cdot 10^{-37}:\\ \;\;\;\;1\\ \mathbf{elif}\;n \leq 2.5 \cdot 10^{+41}:\\ \;\;\;\;-1\\ \mathbf{elif}\;n \leq 10^{+68}:\\ \;\;\;\;1\\ \mathbf{elif}\;n \leq 1.65 \cdot 10^{+131}:\\ \;\;\;\;-1\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
(FPCore (f n)
 :precision binary64
 (if (<= n -1.25e+124)
   1.0
   (if (<= n -5e+111)
     -1.0
     (if (<= n -3.6e-37)
       1.0
       (if (<= n 2.5e+41)
         -1.0
         (if (<= n 1e+68) 1.0 (if (<= n 1.65e+131) -1.0 1.0)))))))
double code(double f, double n) {
	double tmp;
	if (n <= -1.25e+124) {
		tmp = 1.0;
	} else if (n <= -5e+111) {
		tmp = -1.0;
	} else if (n <= -3.6e-37) {
		tmp = 1.0;
	} else if (n <= 2.5e+41) {
		tmp = -1.0;
	} else if (n <= 1e+68) {
		tmp = 1.0;
	} else if (n <= 1.65e+131) {
		tmp = -1.0;
	} else {
		tmp = 1.0;
	}
	return tmp;
}
real(8) function code(f, n)
    real(8), intent (in) :: f
    real(8), intent (in) :: n
    real(8) :: tmp
    if (n <= (-1.25d+124)) then
        tmp = 1.0d0
    else if (n <= (-5d+111)) then
        tmp = -1.0d0
    else if (n <= (-3.6d-37)) then
        tmp = 1.0d0
    else if (n <= 2.5d+41) then
        tmp = -1.0d0
    else if (n <= 1d+68) then
        tmp = 1.0d0
    else if (n <= 1.65d+131) then
        tmp = -1.0d0
    else
        tmp = 1.0d0
    end if
    code = tmp
end function
public static double code(double f, double n) {
	double tmp;
	if (n <= -1.25e+124) {
		tmp = 1.0;
	} else if (n <= -5e+111) {
		tmp = -1.0;
	} else if (n <= -3.6e-37) {
		tmp = 1.0;
	} else if (n <= 2.5e+41) {
		tmp = -1.0;
	} else if (n <= 1e+68) {
		tmp = 1.0;
	} else if (n <= 1.65e+131) {
		tmp = -1.0;
	} else {
		tmp = 1.0;
	}
	return tmp;
}
def code(f, n):
	tmp = 0
	if n <= -1.25e+124:
		tmp = 1.0
	elif n <= -5e+111:
		tmp = -1.0
	elif n <= -3.6e-37:
		tmp = 1.0
	elif n <= 2.5e+41:
		tmp = -1.0
	elif n <= 1e+68:
		tmp = 1.0
	elif n <= 1.65e+131:
		tmp = -1.0
	else:
		tmp = 1.0
	return tmp
function code(f, n)
	tmp = 0.0
	if (n <= -1.25e+124)
		tmp = 1.0;
	elseif (n <= -5e+111)
		tmp = -1.0;
	elseif (n <= -3.6e-37)
		tmp = 1.0;
	elseif (n <= 2.5e+41)
		tmp = -1.0;
	elseif (n <= 1e+68)
		tmp = 1.0;
	elseif (n <= 1.65e+131)
		tmp = -1.0;
	else
		tmp = 1.0;
	end
	return tmp
end
function tmp_2 = code(f, n)
	tmp = 0.0;
	if (n <= -1.25e+124)
		tmp = 1.0;
	elseif (n <= -5e+111)
		tmp = -1.0;
	elseif (n <= -3.6e-37)
		tmp = 1.0;
	elseif (n <= 2.5e+41)
		tmp = -1.0;
	elseif (n <= 1e+68)
		tmp = 1.0;
	elseif (n <= 1.65e+131)
		tmp = -1.0;
	else
		tmp = 1.0;
	end
	tmp_2 = tmp;
end
code[f_, n_] := If[LessEqual[n, -1.25e+124], 1.0, If[LessEqual[n, -5e+111], -1.0, If[LessEqual[n, -3.6e-37], 1.0, If[LessEqual[n, 2.5e+41], -1.0, If[LessEqual[n, 1e+68], 1.0, If[LessEqual[n, 1.65e+131], -1.0, 1.0]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;n \leq -1.25 \cdot 10^{+124}:\\
\;\;\;\;1\\

\mathbf{elif}\;n \leq -5 \cdot 10^{+111}:\\
\;\;\;\;-1\\

\mathbf{elif}\;n \leq -3.6 \cdot 10^{-37}:\\
\;\;\;\;1\\

\mathbf{elif}\;n \leq 2.5 \cdot 10^{+41}:\\
\;\;\;\;-1\\

\mathbf{elif}\;n \leq 10^{+68}:\\
\;\;\;\;1\\

\mathbf{elif}\;n \leq 1.65 \cdot 10^{+131}:\\
\;\;\;\;-1\\

\mathbf{else}:\\
\;\;\;\;1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if n < -1.2499999999999999e124 or -4.9999999999999997e111 < n < -3.60000000000000007e-37 or 2.50000000000000011e41 < n < 9.99999999999999953e67 or 1.6499999999999999e131 < n

    1. Initial program 99.9%

      \[\frac{-\left(f + n\right)}{f - n} \]
    2. Step-by-step derivation
      1. /-rgt-identity99.9%

        \[\leadsto \frac{\color{blue}{\frac{-\left(f + n\right)}{1}}}{f - n} \]
      2. metadata-eval99.9%

        \[\leadsto \frac{\frac{-\left(f + n\right)}{\color{blue}{\frac{-1}{-1}}}}{f - n} \]
      3. neg-mul-199.9%

        \[\leadsto \frac{\frac{\color{blue}{-1 \cdot \left(f + n\right)}}{\frac{-1}{-1}}}{f - n} \]
      4. *-commutative99.9%

        \[\leadsto \frac{\frac{\color{blue}{\left(f + n\right) \cdot -1}}{\frac{-1}{-1}}}{f - n} \]
      5. associate-/l*99.9%

        \[\leadsto \frac{\color{blue}{\frac{f + n}{\frac{\frac{-1}{-1}}{-1}}}}{f - n} \]
      6. metadata-eval99.9%

        \[\leadsto \frac{\frac{f + n}{\frac{\color{blue}{1}}{-1}}}{f - n} \]
      7. metadata-eval99.9%

        \[\leadsto \frac{\frac{f + n}{\color{blue}{-1}}}{f - n} \]
      8. associate-/r*99.9%

        \[\leadsto \color{blue}{\frac{f + n}{-1 \cdot \left(f - n\right)}} \]
      9. neg-mul-199.9%

        \[\leadsto \frac{f + n}{\color{blue}{-\left(f - n\right)}} \]
      10. sub-neg99.9%

        \[\leadsto \frac{f + n}{-\color{blue}{\left(f + \left(-n\right)\right)}} \]
      11. +-commutative99.9%

        \[\leadsto \frac{f + n}{-\color{blue}{\left(\left(-n\right) + f\right)}} \]
      12. distribute-neg-in99.9%

        \[\leadsto \frac{f + n}{\color{blue}{\left(-\left(-n\right)\right) + \left(-f\right)}} \]
      13. remove-double-neg99.9%

        \[\leadsto \frac{f + n}{\color{blue}{n} + \left(-f\right)} \]
      14. sub-neg99.9%

        \[\leadsto \frac{f + n}{\color{blue}{n - f}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{f + n}{n - f}} \]
    4. Add Preprocessing
    5. Taylor expanded in f around 0 86.7%

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

    if -1.2499999999999999e124 < n < -4.9999999999999997e111 or -3.60000000000000007e-37 < n < 2.50000000000000011e41 or 9.99999999999999953e67 < n < 1.6499999999999999e131

    1. Initial program 99.9%

      \[\frac{-\left(f + n\right)}{f - n} \]
    2. Step-by-step derivation
      1. /-rgt-identity99.9%

        \[\leadsto \frac{\color{blue}{\frac{-\left(f + n\right)}{1}}}{f - n} \]
      2. metadata-eval99.9%

        \[\leadsto \frac{\frac{-\left(f + n\right)}{\color{blue}{\frac{-1}{-1}}}}{f - n} \]
      3. neg-mul-199.9%

        \[\leadsto \frac{\frac{\color{blue}{-1 \cdot \left(f + n\right)}}{\frac{-1}{-1}}}{f - n} \]
      4. *-commutative99.9%

        \[\leadsto \frac{\frac{\color{blue}{\left(f + n\right) \cdot -1}}{\frac{-1}{-1}}}{f - n} \]
      5. associate-/l*99.9%

        \[\leadsto \frac{\color{blue}{\frac{f + n}{\frac{\frac{-1}{-1}}{-1}}}}{f - n} \]
      6. metadata-eval99.9%

        \[\leadsto \frac{\frac{f + n}{\frac{\color{blue}{1}}{-1}}}{f - n} \]
      7. metadata-eval99.9%

        \[\leadsto \frac{\frac{f + n}{\color{blue}{-1}}}{f - n} \]
      8. associate-/r*99.9%

        \[\leadsto \color{blue}{\frac{f + n}{-1 \cdot \left(f - n\right)}} \]
      9. neg-mul-199.9%

        \[\leadsto \frac{f + n}{\color{blue}{-\left(f - n\right)}} \]
      10. sub-neg99.9%

        \[\leadsto \frac{f + n}{-\color{blue}{\left(f + \left(-n\right)\right)}} \]
      11. +-commutative99.9%

        \[\leadsto \frac{f + n}{-\color{blue}{\left(\left(-n\right) + f\right)}} \]
      12. distribute-neg-in99.9%

        \[\leadsto \frac{f + n}{\color{blue}{\left(-\left(-n\right)\right) + \left(-f\right)}} \]
      13. remove-double-neg99.9%

        \[\leadsto \frac{f + n}{\color{blue}{n} + \left(-f\right)} \]
      14. sub-neg99.9%

        \[\leadsto \frac{f + n}{\color{blue}{n - f}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{f + n}{n - f}} \]
    4. Add Preprocessing
    5. Taylor expanded in f around inf 82.5%

      \[\leadsto \color{blue}{-1} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification84.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;n \leq -1.25 \cdot 10^{+124}:\\ \;\;\;\;1\\ \mathbf{elif}\;n \leq -5 \cdot 10^{+111}:\\ \;\;\;\;-1\\ \mathbf{elif}\;n \leq -3.6 \cdot 10^{-37}:\\ \;\;\;\;1\\ \mathbf{elif}\;n \leq 2.5 \cdot 10^{+41}:\\ \;\;\;\;-1\\ \mathbf{elif}\;n \leq 10^{+68}:\\ \;\;\;\;1\\ \mathbf{elif}\;n \leq 1.65 \cdot 10^{+131}:\\ \;\;\;\;-1\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 49.9% accurate, 8.0× speedup?

\[\begin{array}{l} \\ -1 \end{array} \]
(FPCore (f n) :precision binary64 -1.0)
double code(double f, double n) {
	return -1.0;
}
real(8) function code(f, n)
    real(8), intent (in) :: f
    real(8), intent (in) :: n
    code = -1.0d0
end function
public static double code(double f, double n) {
	return -1.0;
}
def code(f, n):
	return -1.0
function code(f, n)
	return -1.0
end
function tmp = code(f, n)
	tmp = -1.0;
end
code[f_, n_] := -1.0
\begin{array}{l}

\\
-1
\end{array}
Derivation
  1. Initial program 99.9%

    \[\frac{-\left(f + n\right)}{f - n} \]
  2. Step-by-step derivation
    1. /-rgt-identity99.9%

      \[\leadsto \frac{\color{blue}{\frac{-\left(f + n\right)}{1}}}{f - n} \]
    2. metadata-eval99.9%

      \[\leadsto \frac{\frac{-\left(f + n\right)}{\color{blue}{\frac{-1}{-1}}}}{f - n} \]
    3. neg-mul-199.9%

      \[\leadsto \frac{\frac{\color{blue}{-1 \cdot \left(f + n\right)}}{\frac{-1}{-1}}}{f - n} \]
    4. *-commutative99.9%

      \[\leadsto \frac{\frac{\color{blue}{\left(f + n\right) \cdot -1}}{\frac{-1}{-1}}}{f - n} \]
    5. associate-/l*99.9%

      \[\leadsto \frac{\color{blue}{\frac{f + n}{\frac{\frac{-1}{-1}}{-1}}}}{f - n} \]
    6. metadata-eval99.9%

      \[\leadsto \frac{\frac{f + n}{\frac{\color{blue}{1}}{-1}}}{f - n} \]
    7. metadata-eval99.9%

      \[\leadsto \frac{\frac{f + n}{\color{blue}{-1}}}{f - n} \]
    8. associate-/r*99.9%

      \[\leadsto \color{blue}{\frac{f + n}{-1 \cdot \left(f - n\right)}} \]
    9. neg-mul-199.9%

      \[\leadsto \frac{f + n}{\color{blue}{-\left(f - n\right)}} \]
    10. sub-neg99.9%

      \[\leadsto \frac{f + n}{-\color{blue}{\left(f + \left(-n\right)\right)}} \]
    11. +-commutative99.9%

      \[\leadsto \frac{f + n}{-\color{blue}{\left(\left(-n\right) + f\right)}} \]
    12. distribute-neg-in99.9%

      \[\leadsto \frac{f + n}{\color{blue}{\left(-\left(-n\right)\right) + \left(-f\right)}} \]
    13. remove-double-neg99.9%

      \[\leadsto \frac{f + n}{\color{blue}{n} + \left(-f\right)} \]
    14. sub-neg99.9%

      \[\leadsto \frac{f + n}{\color{blue}{n - f}} \]
  3. Simplified99.9%

    \[\leadsto \color{blue}{\frac{f + n}{n - f}} \]
  4. Add Preprocessing
  5. Taylor expanded in f around inf 50.9%

    \[\leadsto \color{blue}{-1} \]
  6. Final simplification50.9%

    \[\leadsto -1 \]
  7. Add Preprocessing

Reproduce

?
herbie shell --seed 2024027 
(FPCore (f n)
  :name "subtraction fraction"
  :precision binary64
  (/ (- (+ f n)) (- f n)))