subtraction fraction

Percentage Accurate: 100.0% → 100.0%
Time: 3.4s
Alternatives: 6
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 6 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, 0.7× speedup?

\[\begin{array}{l} \\ \frac{1}{\frac{1}{\frac{n + f}{n - f}}} \end{array} \]
(FPCore (f n) :precision binary64 (/ 1.0 (/ 1.0 (/ (+ n f) (- n f)))))
double code(double f, double n) {
	return 1.0 / (1.0 / ((n + f) / (n - f)));
}
real(8) function code(f, n)
    real(8), intent (in) :: f
    real(8), intent (in) :: n
    code = 1.0d0 / (1.0d0 / ((n + f) / (n - f)))
end function
public static double code(double f, double n) {
	return 1.0 / (1.0 / ((n + f) / (n - f)));
}
def code(f, n):
	return 1.0 / (1.0 / ((n + f) / (n - f)))
function code(f, n)
	return Float64(1.0 / Float64(1.0 / Float64(Float64(n + f) / Float64(n - f))))
end
function tmp = code(f, n)
	tmp = 1.0 / (1.0 / ((n + f) / (n - f)));
end
code[f_, n_] := N[(1.0 / N[(1.0 / N[(N[(n + f), $MachinePrecision] / N[(n - f), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{\frac{1}{\frac{n + f}{n - f}}}
\end{array}
Derivation
  1. Initial program 100.0%

    \[\frac{-\left(f + n\right)}{f - n} \]
  2. Step-by-step derivation
    1. neg-mul-1100.0%

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

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

      \[\leadsto \color{blue}{\frac{f + n}{\frac{f - n}{-1}}} \]
    4. div-sub100.0%

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

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

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

      \[\leadsto \frac{f + n}{\color{blue}{\frac{f \cdot -1}{--1}} - \frac{n}{-1}} \]
    8. *-commutative100.0%

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

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

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

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

      \[\leadsto \frac{f + n}{\frac{-f}{--1} - \color{blue}{\frac{n \cdot -1}{--1}}} \]
    13. *-commutative100.0%

      \[\leadsto \frac{f + n}{\frac{-f}{--1} - \frac{\color{blue}{-1 \cdot n}}{--1}} \]
    14. neg-mul-1100.0%

      \[\leadsto \frac{f + n}{\frac{-f}{--1} - \frac{\color{blue}{-n}}{--1}} \]
    15. div-sub100.0%

      \[\leadsto \frac{f + n}{\color{blue}{\frac{\left(-f\right) - \left(-n\right)}{--1}}} \]
    16. unsub-neg100.0%

      \[\leadsto \frac{f + n}{\frac{\color{blue}{\left(-f\right) + \left(-\left(-n\right)\right)}}{--1}} \]
    17. remove-double-neg100.0%

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

      \[\leadsto \frac{f + n}{\frac{\color{blue}{n + \left(-f\right)}}{--1}} \]
    19. sub-neg100.0%

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

      \[\leadsto \frac{f + n}{\frac{n - f}{\color{blue}{1}}} \]
    21. /-rgt-identity100.0%

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

    \[\leadsto \color{blue}{\frac{f + n}{n - f}} \]
  4. Step-by-step derivation
    1. clear-num100.0%

      \[\leadsto \color{blue}{\frac{1}{\frac{n - f}{f + n}}} \]
    2. associate-/r/99.8%

      \[\leadsto \color{blue}{\frac{1}{n - f} \cdot \left(f + n\right)} \]
  5. Applied egg-rr99.8%

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

      \[\leadsto \color{blue}{\frac{1 \cdot \left(f + n\right)}{n - f}} \]
    2. add-sqr-sqrt46.8%

      \[\leadsto \frac{1 \cdot \left(f + n\right)}{\color{blue}{\sqrt{n - f} \cdot \sqrt{n - f}}} \]
    3. times-frac46.8%

      \[\leadsto \color{blue}{\frac{1}{\sqrt{n - f}} \cdot \frac{f + n}{\sqrt{n - f}}} \]
    4. clear-num46.9%

      \[\leadsto \frac{1}{\sqrt{n - f}} \cdot \color{blue}{\frac{1}{\frac{\sqrt{n - f}}{f + n}}} \]
    5. div-inv46.9%

      \[\leadsto \color{blue}{\frac{\frac{1}{\sqrt{n - f}}}{\frac{\sqrt{n - f}}{f + n}}} \]
    6. clear-num46.8%

      \[\leadsto \color{blue}{\frac{1}{\frac{\frac{\sqrt{n - f}}{f + n}}{\frac{1}{\sqrt{n - f}}}}} \]
    7. clear-num46.8%

      \[\leadsto \frac{1}{\color{blue}{\frac{1}{\frac{\frac{1}{\sqrt{n - f}}}{\frac{\sqrt{n - f}}{f + n}}}}} \]
    8. div-inv46.8%

      \[\leadsto \frac{1}{\frac{1}{\color{blue}{\frac{1}{\sqrt{n - f}} \cdot \frac{1}{\frac{\sqrt{n - f}}{f + n}}}}} \]
    9. clear-num46.7%

      \[\leadsto \frac{1}{\frac{1}{\frac{1}{\sqrt{n - f}} \cdot \color{blue}{\frac{f + n}{\sqrt{n - f}}}}} \]
    10. times-frac46.7%

      \[\leadsto \frac{1}{\frac{1}{\color{blue}{\frac{1 \cdot \left(f + n\right)}{\sqrt{n - f} \cdot \sqrt{n - f}}}}} \]
    11. add-sqr-sqrt100.0%

      \[\leadsto \frac{1}{\frac{1}{\frac{1 \cdot \left(f + n\right)}{\color{blue}{n - f}}}} \]
    12. *-un-lft-identity100.0%

      \[\leadsto \frac{1}{\frac{1}{\frac{\color{blue}{f + n}}{n - f}}} \]
    13. +-commutative100.0%

      \[\leadsto \frac{1}{\frac{1}{\frac{\color{blue}{n + f}}{n - f}}} \]
  7. Applied egg-rr100.0%

    \[\leadsto \color{blue}{\frac{1}{\frac{1}{\frac{n + f}{n - f}}}} \]
  8. Final simplification100.0%

    \[\leadsto \frac{1}{\frac{1}{\frac{n + f}{n - f}}} \]

Alternative 2: 74.4% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;n \leq -2.2 \cdot 10^{-71} \lor \neg \left(n \leq 6 \cdot 10^{+50}\right):\\ \;\;\;\;1 + 2 \cdot \frac{f}{n}\\ \mathbf{else}:\\ \;\;\;\;-1\\ \end{array} \end{array} \]
(FPCore (f n)
 :precision binary64
 (if (or (<= n -2.2e-71) (not (<= n 6e+50))) (+ 1.0 (* 2.0 (/ f n))) -1.0))
double code(double f, double n) {
	double tmp;
	if ((n <= -2.2e-71) || !(n <= 6e+50)) {
		tmp = 1.0 + (2.0 * (f / n));
	} 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 <= (-2.2d-71)) .or. (.not. (n <= 6d+50))) then
        tmp = 1.0d0 + (2.0d0 * (f / n))
    else
        tmp = -1.0d0
    end if
    code = tmp
end function
public static double code(double f, double n) {
	double tmp;
	if ((n <= -2.2e-71) || !(n <= 6e+50)) {
		tmp = 1.0 + (2.0 * (f / n));
	} else {
		tmp = -1.0;
	}
	return tmp;
}
def code(f, n):
	tmp = 0
	if (n <= -2.2e-71) or not (n <= 6e+50):
		tmp = 1.0 + (2.0 * (f / n))
	else:
		tmp = -1.0
	return tmp
function code(f, n)
	tmp = 0.0
	if ((n <= -2.2e-71) || !(n <= 6e+50))
		tmp = Float64(1.0 + Float64(2.0 * Float64(f / n)));
	else
		tmp = -1.0;
	end
	return tmp
end
function tmp_2 = code(f, n)
	tmp = 0.0;
	if ((n <= -2.2e-71) || ~((n <= 6e+50)))
		tmp = 1.0 + (2.0 * (f / n));
	else
		tmp = -1.0;
	end
	tmp_2 = tmp;
end
code[f_, n_] := If[Or[LessEqual[n, -2.2e-71], N[Not[LessEqual[n, 6e+50]], $MachinePrecision]], N[(1.0 + N[(2.0 * N[(f / n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1.0]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;n \leq -2.2 \cdot 10^{-71} \lor \neg \left(n \leq 6 \cdot 10^{+50}\right):\\
\;\;\;\;1 + 2 \cdot \frac{f}{n}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if n < -2.19999999999999997e-71 or 5.9999999999999996e50 < n

    1. Initial program 100.0%

      \[\frac{-\left(f + n\right)}{f - n} \]
    2. Step-by-step derivation
      1. neg-mul-1100.0%

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

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

        \[\leadsto \color{blue}{\frac{f + n}{\frac{f - n}{-1}}} \]
      4. div-sub100.0%

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

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

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

        \[\leadsto \frac{f + n}{\color{blue}{\frac{f \cdot -1}{--1}} - \frac{n}{-1}} \]
      8. *-commutative100.0%

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

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

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

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

        \[\leadsto \frac{f + n}{\frac{-f}{--1} - \color{blue}{\frac{n \cdot -1}{--1}}} \]
      13. *-commutative100.0%

        \[\leadsto \frac{f + n}{\frac{-f}{--1} - \frac{\color{blue}{-1 \cdot n}}{--1}} \]
      14. neg-mul-1100.0%

        \[\leadsto \frac{f + n}{\frac{-f}{--1} - \frac{\color{blue}{-n}}{--1}} \]
      15. div-sub100.0%

        \[\leadsto \frac{f + n}{\color{blue}{\frac{\left(-f\right) - \left(-n\right)}{--1}}} \]
      16. unsub-neg100.0%

        \[\leadsto \frac{f + n}{\frac{\color{blue}{\left(-f\right) + \left(-\left(-n\right)\right)}}{--1}} \]
      17. remove-double-neg100.0%

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

        \[\leadsto \frac{f + n}{\frac{\color{blue}{n + \left(-f\right)}}{--1}} \]
      19. sub-neg100.0%

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

        \[\leadsto \frac{f + n}{\frac{n - f}{\color{blue}{1}}} \]
      21. /-rgt-identity100.0%

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

      \[\leadsto \color{blue}{\frac{f + n}{n - f}} \]
    4. Taylor expanded in f around 0 80.1%

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

    if -2.19999999999999997e-71 < n < 5.9999999999999996e50

    1. Initial program 100.0%

      \[\frac{-\left(f + n\right)}{f - n} \]
    2. Step-by-step derivation
      1. neg-mul-1100.0%

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

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

        \[\leadsto \color{blue}{\frac{f + n}{\frac{f - n}{-1}}} \]
      4. div-sub100.0%

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

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

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

        \[\leadsto \frac{f + n}{\color{blue}{\frac{f \cdot -1}{--1}} - \frac{n}{-1}} \]
      8. *-commutative100.0%

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

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

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

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

        \[\leadsto \frac{f + n}{\frac{-f}{--1} - \color{blue}{\frac{n \cdot -1}{--1}}} \]
      13. *-commutative100.0%

        \[\leadsto \frac{f + n}{\frac{-f}{--1} - \frac{\color{blue}{-1 \cdot n}}{--1}} \]
      14. neg-mul-1100.0%

        \[\leadsto \frac{f + n}{\frac{-f}{--1} - \frac{\color{blue}{-n}}{--1}} \]
      15. div-sub100.0%

        \[\leadsto \frac{f + n}{\color{blue}{\frac{\left(-f\right) - \left(-n\right)}{--1}}} \]
      16. unsub-neg100.0%

        \[\leadsto \frac{f + n}{\frac{\color{blue}{\left(-f\right) + \left(-\left(-n\right)\right)}}{--1}} \]
      17. remove-double-neg100.0%

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

        \[\leadsto \frac{f + n}{\frac{\color{blue}{n + \left(-f\right)}}{--1}} \]
      19. sub-neg100.0%

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

        \[\leadsto \frac{f + n}{\frac{n - f}{\color{blue}{1}}} \]
      21. /-rgt-identity100.0%

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

      \[\leadsto \color{blue}{\frac{f + n}{n - f}} \]
    4. Taylor expanded in f around inf 77.0%

      \[\leadsto \color{blue}{-1} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification78.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;n \leq -2.2 \cdot 10^{-71} \lor \neg \left(n \leq 6 \cdot 10^{+50}\right):\\ \;\;\;\;1 + 2 \cdot \frac{f}{n}\\ \mathbf{else}:\\ \;\;\;\;-1\\ \end{array} \]

Alternative 3: 75.5% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;n \leq -2.05 \cdot 10^{-39} \lor \neg \left(n \leq 8.2 \cdot 10^{+49}\right):\\ \;\;\;\;1 + 2 \cdot \frac{f}{n}\\ \mathbf{else}:\\ \;\;\;\;-2 \cdot \frac{n}{f} + -1\\ \end{array} \end{array} \]
(FPCore (f n)
 :precision binary64
 (if (or (<= n -2.05e-39) (not (<= n 8.2e+49)))
   (+ 1.0 (* 2.0 (/ f n)))
   (+ (* -2.0 (/ n f)) -1.0)))
double code(double f, double n) {
	double tmp;
	if ((n <= -2.05e-39) || !(n <= 8.2e+49)) {
		tmp = 1.0 + (2.0 * (f / n));
	} else {
		tmp = (-2.0 * (n / f)) + -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 <= (-2.05d-39)) .or. (.not. (n <= 8.2d+49))) then
        tmp = 1.0d0 + (2.0d0 * (f / n))
    else
        tmp = ((-2.0d0) * (n / f)) + (-1.0d0)
    end if
    code = tmp
end function
public static double code(double f, double n) {
	double tmp;
	if ((n <= -2.05e-39) || !(n <= 8.2e+49)) {
		tmp = 1.0 + (2.0 * (f / n));
	} else {
		tmp = (-2.0 * (n / f)) + -1.0;
	}
	return tmp;
}
def code(f, n):
	tmp = 0
	if (n <= -2.05e-39) or not (n <= 8.2e+49):
		tmp = 1.0 + (2.0 * (f / n))
	else:
		tmp = (-2.0 * (n / f)) + -1.0
	return tmp
function code(f, n)
	tmp = 0.0
	if ((n <= -2.05e-39) || !(n <= 8.2e+49))
		tmp = Float64(1.0 + Float64(2.0 * Float64(f / n)));
	else
		tmp = Float64(Float64(-2.0 * Float64(n / f)) + -1.0);
	end
	return tmp
end
function tmp_2 = code(f, n)
	tmp = 0.0;
	if ((n <= -2.05e-39) || ~((n <= 8.2e+49)))
		tmp = 1.0 + (2.0 * (f / n));
	else
		tmp = (-2.0 * (n / f)) + -1.0;
	end
	tmp_2 = tmp;
end
code[f_, n_] := If[Or[LessEqual[n, -2.05e-39], N[Not[LessEqual[n, 8.2e+49]], $MachinePrecision]], N[(1.0 + N[(2.0 * N[(f / n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(-2.0 * N[(n / f), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;n \leq -2.05 \cdot 10^{-39} \lor \neg \left(n \leq 8.2 \cdot 10^{+49}\right):\\
\;\;\;\;1 + 2 \cdot \frac{f}{n}\\

\mathbf{else}:\\
\;\;\;\;-2 \cdot \frac{n}{f} + -1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if n < -2.05e-39 or 8.2e49 < n

    1. Initial program 100.0%

      \[\frac{-\left(f + n\right)}{f - n} \]
    2. Step-by-step derivation
      1. neg-mul-1100.0%

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

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

        \[\leadsto \color{blue}{\frac{f + n}{\frac{f - n}{-1}}} \]
      4. div-sub100.0%

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

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

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

        \[\leadsto \frac{f + n}{\color{blue}{\frac{f \cdot -1}{--1}} - \frac{n}{-1}} \]
      8. *-commutative100.0%

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

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

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

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

        \[\leadsto \frac{f + n}{\frac{-f}{--1} - \color{blue}{\frac{n \cdot -1}{--1}}} \]
      13. *-commutative100.0%

        \[\leadsto \frac{f + n}{\frac{-f}{--1} - \frac{\color{blue}{-1 \cdot n}}{--1}} \]
      14. neg-mul-1100.0%

        \[\leadsto \frac{f + n}{\frac{-f}{--1} - \frac{\color{blue}{-n}}{--1}} \]
      15. div-sub100.0%

        \[\leadsto \frac{f + n}{\color{blue}{\frac{\left(-f\right) - \left(-n\right)}{--1}}} \]
      16. unsub-neg100.0%

        \[\leadsto \frac{f + n}{\frac{\color{blue}{\left(-f\right) + \left(-\left(-n\right)\right)}}{--1}} \]
      17. remove-double-neg100.0%

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

        \[\leadsto \frac{f + n}{\frac{\color{blue}{n + \left(-f\right)}}{--1}} \]
      19. sub-neg100.0%

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

        \[\leadsto \frac{f + n}{\frac{n - f}{\color{blue}{1}}} \]
      21. /-rgt-identity100.0%

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

      \[\leadsto \color{blue}{\frac{f + n}{n - f}} \]
    4. Taylor expanded in f around 0 82.1%

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

    if -2.05e-39 < n < 8.2e49

    1. Initial program 100.0%

      \[\frac{-\left(f + n\right)}{f - n} \]
    2. Step-by-step derivation
      1. neg-mul-1100.0%

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

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

        \[\leadsto \color{blue}{\frac{f + n}{\frac{f - n}{-1}}} \]
      4. div-sub100.0%

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

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

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

        \[\leadsto \frac{f + n}{\color{blue}{\frac{f \cdot -1}{--1}} - \frac{n}{-1}} \]
      8. *-commutative100.0%

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

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

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

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

        \[\leadsto \frac{f + n}{\frac{-f}{--1} - \color{blue}{\frac{n \cdot -1}{--1}}} \]
      13. *-commutative100.0%

        \[\leadsto \frac{f + n}{\frac{-f}{--1} - \frac{\color{blue}{-1 \cdot n}}{--1}} \]
      14. neg-mul-1100.0%

        \[\leadsto \frac{f + n}{\frac{-f}{--1} - \frac{\color{blue}{-n}}{--1}} \]
      15. div-sub100.0%

        \[\leadsto \frac{f + n}{\color{blue}{\frac{\left(-f\right) - \left(-n\right)}{--1}}} \]
      16. unsub-neg100.0%

        \[\leadsto \frac{f + n}{\frac{\color{blue}{\left(-f\right) + \left(-\left(-n\right)\right)}}{--1}} \]
      17. remove-double-neg100.0%

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

        \[\leadsto \frac{f + n}{\frac{\color{blue}{n + \left(-f\right)}}{--1}} \]
      19. sub-neg100.0%

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

        \[\leadsto \frac{f + n}{\frac{n - f}{\color{blue}{1}}} \]
      21. /-rgt-identity100.0%

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

      \[\leadsto \color{blue}{\frac{f + n}{n - f}} \]
    4. Taylor expanded in n around 0 76.4%

      \[\leadsto \color{blue}{-2 \cdot \frac{n}{f} - 1} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification79.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;n \leq -2.05 \cdot 10^{-39} \lor \neg \left(n \leq 8.2 \cdot 10^{+49}\right):\\ \;\;\;\;1 + 2 \cdot \frac{f}{n}\\ \mathbf{else}:\\ \;\;\;\;-2 \cdot \frac{n}{f} + -1\\ \end{array} \]

Alternative 4: 100.0% accurate, 1.1× speedup?

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

\\
\frac{n + f}{n - f}
\end{array}
Derivation
  1. Initial program 100.0%

    \[\frac{-\left(f + n\right)}{f - n} \]
  2. Step-by-step derivation
    1. neg-mul-1100.0%

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

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

      \[\leadsto \color{blue}{\frac{f + n}{\frac{f - n}{-1}}} \]
    4. div-sub100.0%

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

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

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

      \[\leadsto \frac{f + n}{\color{blue}{\frac{f \cdot -1}{--1}} - \frac{n}{-1}} \]
    8. *-commutative100.0%

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

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

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

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

      \[\leadsto \frac{f + n}{\frac{-f}{--1} - \color{blue}{\frac{n \cdot -1}{--1}}} \]
    13. *-commutative100.0%

      \[\leadsto \frac{f + n}{\frac{-f}{--1} - \frac{\color{blue}{-1 \cdot n}}{--1}} \]
    14. neg-mul-1100.0%

      \[\leadsto \frac{f + n}{\frac{-f}{--1} - \frac{\color{blue}{-n}}{--1}} \]
    15. div-sub100.0%

      \[\leadsto \frac{f + n}{\color{blue}{\frac{\left(-f\right) - \left(-n\right)}{--1}}} \]
    16. unsub-neg100.0%

      \[\leadsto \frac{f + n}{\frac{\color{blue}{\left(-f\right) + \left(-\left(-n\right)\right)}}{--1}} \]
    17. remove-double-neg100.0%

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

      \[\leadsto \frac{f + n}{\frac{\color{blue}{n + \left(-f\right)}}{--1}} \]
    19. sub-neg100.0%

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

      \[\leadsto \frac{f + n}{\frac{n - f}{\color{blue}{1}}} \]
    21. /-rgt-identity100.0%

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

    \[\leadsto \color{blue}{\frac{f + n}{n - f}} \]
  4. Final simplification100.0%

    \[\leadsto \frac{n + f}{n - f} \]

Alternative 5: 73.0% accurate, 1.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;n \leq -1.86 \cdot 10^{-93}:\\ \;\;\;\;1\\ \mathbf{elif}\;n \leq 5 \cdot 10^{+49}:\\ \;\;\;\;-1\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
(FPCore (f n)
 :precision binary64
 (if (<= n -1.86e-93) 1.0 (if (<= n 5e+49) -1.0 1.0)))
double code(double f, double n) {
	double tmp;
	if (n <= -1.86e-93) {
		tmp = 1.0;
	} else if (n <= 5e+49) {
		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 <= (-1.86d-93)) then
        tmp = 1.0d0
    else if (n <= 5d+49) 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 <= -1.86e-93) {
		tmp = 1.0;
	} else if (n <= 5e+49) {
		tmp = -1.0;
	} else {
		tmp = 1.0;
	}
	return tmp;
}
def code(f, n):
	tmp = 0
	if n <= -1.86e-93:
		tmp = 1.0
	elif n <= 5e+49:
		tmp = -1.0
	else:
		tmp = 1.0
	return tmp
function code(f, n)
	tmp = 0.0
	if (n <= -1.86e-93)
		tmp = 1.0;
	elseif (n <= 5e+49)
		tmp = -1.0;
	else
		tmp = 1.0;
	end
	return tmp
end
function tmp_2 = code(f, n)
	tmp = 0.0;
	if (n <= -1.86e-93)
		tmp = 1.0;
	elseif (n <= 5e+49)
		tmp = -1.0;
	else
		tmp = 1.0;
	end
	tmp_2 = tmp;
end
code[f_, n_] := If[LessEqual[n, -1.86e-93], 1.0, If[LessEqual[n, 5e+49], -1.0, 1.0]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;n \leq -1.86 \cdot 10^{-93}:\\
\;\;\;\;1\\

\mathbf{elif}\;n \leq 5 \cdot 10^{+49}:\\
\;\;\;\;-1\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if n < -1.8600000000000001e-93 or 5.0000000000000004e49 < n

    1. Initial program 100.0%

      \[\frac{-\left(f + n\right)}{f - n} \]
    2. Step-by-step derivation
      1. neg-mul-1100.0%

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

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

        \[\leadsto \color{blue}{\frac{f + n}{\frac{f - n}{-1}}} \]
      4. div-sub100.0%

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

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

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

        \[\leadsto \frac{f + n}{\color{blue}{\frac{f \cdot -1}{--1}} - \frac{n}{-1}} \]
      8. *-commutative100.0%

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

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

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

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

        \[\leadsto \frac{f + n}{\frac{-f}{--1} - \color{blue}{\frac{n \cdot -1}{--1}}} \]
      13. *-commutative100.0%

        \[\leadsto \frac{f + n}{\frac{-f}{--1} - \frac{\color{blue}{-1 \cdot n}}{--1}} \]
      14. neg-mul-1100.0%

        \[\leadsto \frac{f + n}{\frac{-f}{--1} - \frac{\color{blue}{-n}}{--1}} \]
      15. div-sub100.0%

        \[\leadsto \frac{f + n}{\color{blue}{\frac{\left(-f\right) - \left(-n\right)}{--1}}} \]
      16. unsub-neg100.0%

        \[\leadsto \frac{f + n}{\frac{\color{blue}{\left(-f\right) + \left(-\left(-n\right)\right)}}{--1}} \]
      17. remove-double-neg100.0%

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

        \[\leadsto \frac{f + n}{\frac{\color{blue}{n + \left(-f\right)}}{--1}} \]
      19. sub-neg100.0%

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

        \[\leadsto \frac{f + n}{\frac{n - f}{\color{blue}{1}}} \]
      21. /-rgt-identity100.0%

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

      \[\leadsto \color{blue}{\frac{f + n}{n - f}} \]
    4. Taylor expanded in f around 0 78.5%

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

    if -1.8600000000000001e-93 < n < 5.0000000000000004e49

    1. Initial program 100.0%

      \[\frac{-\left(f + n\right)}{f - n} \]
    2. Step-by-step derivation
      1. neg-mul-1100.0%

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

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

        \[\leadsto \color{blue}{\frac{f + n}{\frac{f - n}{-1}}} \]
      4. div-sub100.0%

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

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

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

        \[\leadsto \frac{f + n}{\color{blue}{\frac{f \cdot -1}{--1}} - \frac{n}{-1}} \]
      8. *-commutative100.0%

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

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

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

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

        \[\leadsto \frac{f + n}{\frac{-f}{--1} - \color{blue}{\frac{n \cdot -1}{--1}}} \]
      13. *-commutative100.0%

        \[\leadsto \frac{f + n}{\frac{-f}{--1} - \frac{\color{blue}{-1 \cdot n}}{--1}} \]
      14. neg-mul-1100.0%

        \[\leadsto \frac{f + n}{\frac{-f}{--1} - \frac{\color{blue}{-n}}{--1}} \]
      15. div-sub100.0%

        \[\leadsto \frac{f + n}{\color{blue}{\frac{\left(-f\right) - \left(-n\right)}{--1}}} \]
      16. unsub-neg100.0%

        \[\leadsto \frac{f + n}{\frac{\color{blue}{\left(-f\right) + \left(-\left(-n\right)\right)}}{--1}} \]
      17. remove-double-neg100.0%

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

        \[\leadsto \frac{f + n}{\frac{\color{blue}{n + \left(-f\right)}}{--1}} \]
      19. sub-neg100.0%

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

        \[\leadsto \frac{f + n}{\frac{n - f}{\color{blue}{1}}} \]
      21. /-rgt-identity100.0%

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

      \[\leadsto \color{blue}{\frac{f + n}{n - f}} \]
    4. Taylor expanded in f around inf 77.8%

      \[\leadsto \color{blue}{-1} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification78.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;n \leq -1.86 \cdot 10^{-93}:\\ \;\;\;\;1\\ \mathbf{elif}\;n \leq 5 \cdot 10^{+49}:\\ \;\;\;\;-1\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]

Alternative 6: 50.8% 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 100.0%

    \[\frac{-\left(f + n\right)}{f - n} \]
  2. Step-by-step derivation
    1. neg-mul-1100.0%

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

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

      \[\leadsto \color{blue}{\frac{f + n}{\frac{f - n}{-1}}} \]
    4. div-sub100.0%

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

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

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

      \[\leadsto \frac{f + n}{\color{blue}{\frac{f \cdot -1}{--1}} - \frac{n}{-1}} \]
    8. *-commutative100.0%

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

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

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

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

      \[\leadsto \frac{f + n}{\frac{-f}{--1} - \color{blue}{\frac{n \cdot -1}{--1}}} \]
    13. *-commutative100.0%

      \[\leadsto \frac{f + n}{\frac{-f}{--1} - \frac{\color{blue}{-1 \cdot n}}{--1}} \]
    14. neg-mul-1100.0%

      \[\leadsto \frac{f + n}{\frac{-f}{--1} - \frac{\color{blue}{-n}}{--1}} \]
    15. div-sub100.0%

      \[\leadsto \frac{f + n}{\color{blue}{\frac{\left(-f\right) - \left(-n\right)}{--1}}} \]
    16. unsub-neg100.0%

      \[\leadsto \frac{f + n}{\frac{\color{blue}{\left(-f\right) + \left(-\left(-n\right)\right)}}{--1}} \]
    17. remove-double-neg100.0%

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

      \[\leadsto \frac{f + n}{\frac{\color{blue}{n + \left(-f\right)}}{--1}} \]
    19. sub-neg100.0%

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

      \[\leadsto \frac{f + n}{\frac{n - f}{\color{blue}{1}}} \]
    21. /-rgt-identity100.0%

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

    \[\leadsto \color{blue}{\frac{f + n}{n - f}} \]
  4. Taylor expanded in f around inf 49.0%

    \[\leadsto \color{blue}{-1} \]
  5. Final simplification49.0%

    \[\leadsto -1 \]

Reproduce

?
herbie shell --seed 2023217 
(FPCore (f n)
  :name "subtraction fraction"
  :precision binary64
  (/ (- (+ f n)) (- f n)))