2log (problem 3.3.6)

Percentage Accurate: 23.7% → 99.3%
Time: 9.4s
Alternatives: 10
Speedup: 68.3×

Specification

?
\[N > 1 \land N < 10^{+40}\]
\[\begin{array}{l} \\ \log \left(N + 1\right) - \log N \end{array} \]
(FPCore (N) :precision binary64 (- (log (+ N 1.0)) (log N)))
double code(double N) {
	return log((N + 1.0)) - log(N);
}
real(8) function code(n)
    real(8), intent (in) :: n
    code = log((n + 1.0d0)) - log(n)
end function
public static double code(double N) {
	return Math.log((N + 1.0)) - Math.log(N);
}
def code(N):
	return math.log((N + 1.0)) - math.log(N)
function code(N)
	return Float64(log(Float64(N + 1.0)) - log(N))
end
function tmp = code(N)
	tmp = log((N + 1.0)) - log(N);
end
code[N_] := N[(N[Log[N[(N + 1.0), $MachinePrecision]], $MachinePrecision] - N[Log[N], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\log \left(N + 1\right) - \log 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 10 alternatives:

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

Initial Program: 23.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \log \left(N + 1\right) - \log N \end{array} \]
(FPCore (N) :precision binary64 (- (log (+ N 1.0)) (log N)))
double code(double N) {
	return log((N + 1.0)) - log(N);
}
real(8) function code(n)
    real(8), intent (in) :: n
    code = log((n + 1.0d0)) - log(n)
end function
public static double code(double N) {
	return Math.log((N + 1.0)) - Math.log(N);
}
def code(N):
	return math.log((N + 1.0)) - math.log(N)
function code(N)
	return Float64(log(Float64(N + 1.0)) - log(N))
end
function tmp = code(N)
	tmp = log((N + 1.0)) - log(N);
end
code[N_] := N[(N[Log[N[(N + 1.0), $MachinePrecision]], $MachinePrecision] - N[Log[N], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\log \left(N + 1\right) - \log N
\end{array}

Alternative 1: 99.3% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\log \left(N + 1\right) - \log N \leq 0.001:\\ \;\;\;\;\frac{1}{N \cdot \left(\frac{0.041666666666666664}{{N}^{3}} - \left(-1 + \frac{\frac{0.08333333333333333}{N} + -0.5}{N}\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\log \left(\frac{N + 1}{N}\right)\\ \end{array} \end{array} \]
(FPCore (N)
 :precision binary64
 (if (<= (- (log (+ N 1.0)) (log N)) 0.001)
   (/
    1.0
    (*
     N
     (-
      (/ 0.041666666666666664 (pow N 3.0))
      (+ -1.0 (/ (+ (/ 0.08333333333333333 N) -0.5) N)))))
   (log (/ (+ N 1.0) N))))
double code(double N) {
	double tmp;
	if ((log((N + 1.0)) - log(N)) <= 0.001) {
		tmp = 1.0 / (N * ((0.041666666666666664 / pow(N, 3.0)) - (-1.0 + (((0.08333333333333333 / N) + -0.5) / N))));
	} else {
		tmp = log(((N + 1.0) / N));
	}
	return tmp;
}
real(8) function code(n)
    real(8), intent (in) :: n
    real(8) :: tmp
    if ((log((n + 1.0d0)) - log(n)) <= 0.001d0) then
        tmp = 1.0d0 / (n * ((0.041666666666666664d0 / (n ** 3.0d0)) - ((-1.0d0) + (((0.08333333333333333d0 / n) + (-0.5d0)) / n))))
    else
        tmp = log(((n + 1.0d0) / n))
    end if
    code = tmp
end function
public static double code(double N) {
	double tmp;
	if ((Math.log((N + 1.0)) - Math.log(N)) <= 0.001) {
		tmp = 1.0 / (N * ((0.041666666666666664 / Math.pow(N, 3.0)) - (-1.0 + (((0.08333333333333333 / N) + -0.5) / N))));
	} else {
		tmp = Math.log(((N + 1.0) / N));
	}
	return tmp;
}
def code(N):
	tmp = 0
	if (math.log((N + 1.0)) - math.log(N)) <= 0.001:
		tmp = 1.0 / (N * ((0.041666666666666664 / math.pow(N, 3.0)) - (-1.0 + (((0.08333333333333333 / N) + -0.5) / N))))
	else:
		tmp = math.log(((N + 1.0) / N))
	return tmp
function code(N)
	tmp = 0.0
	if (Float64(log(Float64(N + 1.0)) - log(N)) <= 0.001)
		tmp = Float64(1.0 / Float64(N * Float64(Float64(0.041666666666666664 / (N ^ 3.0)) - Float64(-1.0 + Float64(Float64(Float64(0.08333333333333333 / N) + -0.5) / N)))));
	else
		tmp = log(Float64(Float64(N + 1.0) / N));
	end
	return tmp
end
function tmp_2 = code(N)
	tmp = 0.0;
	if ((log((N + 1.0)) - log(N)) <= 0.001)
		tmp = 1.0 / (N * ((0.041666666666666664 / (N ^ 3.0)) - (-1.0 + (((0.08333333333333333 / N) + -0.5) / N))));
	else
		tmp = log(((N + 1.0) / N));
	end
	tmp_2 = tmp;
end
code[N_] := If[LessEqual[N[(N[Log[N[(N + 1.0), $MachinePrecision]], $MachinePrecision] - N[Log[N], $MachinePrecision]), $MachinePrecision], 0.001], N[(1.0 / N[(N * N[(N[(0.041666666666666664 / N[Power[N, 3.0], $MachinePrecision]), $MachinePrecision] - N[(-1.0 + N[(N[(N[(0.08333333333333333 / N), $MachinePrecision] + -0.5), $MachinePrecision] / N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[Log[N[(N[(N + 1.0), $MachinePrecision] / N), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\log \left(N + 1\right) - \log N \leq 0.001:\\
\;\;\;\;\frac{1}{N \cdot \left(\frac{0.041666666666666664}{{N}^{3}} - \left(-1 + \frac{\frac{0.08333333333333333}{N} + -0.5}{N}\right)\right)}\\

\mathbf{else}:\\
\;\;\;\;\log \left(\frac{N + 1}{N}\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (log.f64 (+.f64 N #s(literal 1 binary64))) (log.f64 N)) < 1e-3

    1. Initial program 17.1%

      \[\log \left(N + 1\right) - \log N \]
    2. Step-by-step derivation
      1. +-commutative17.1%

        \[\leadsto \log \color{blue}{\left(1 + N\right)} - \log N \]
      2. log1p-define17.1%

        \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right)} - \log N \]
    3. Simplified17.1%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right) - \log N} \]
    4. Add Preprocessing
    5. Taylor expanded in N around inf 99.6%

      \[\leadsto \color{blue}{\frac{\left(1 + \frac{0.3333333333333333}{{N}^{2}}\right) - \left(0.5 \cdot \frac{1}{N} + 0.25 \cdot \frac{1}{{N}^{3}}\right)}{N}} \]
    6. Simplified99.6%

      \[\leadsto \color{blue}{\frac{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}{N}} \]
    7. Step-by-step derivation
      1. clear-num99.7%

        \[\leadsto \color{blue}{\frac{1}{\frac{N}{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}}} \]
      2. inv-pow99.7%

        \[\leadsto \color{blue}{{\left(\frac{N}{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}\right)}^{-1}} \]
      3. associate--l+99.7%

        \[\leadsto {\left(\frac{N}{\color{blue}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - \frac{0.25}{{N}^{3}}\right)}}\right)}^{-1} \]
      4. div-inv99.7%

        \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - \color{blue}{0.25 \cdot \frac{1}{{N}^{3}}}\right)}\right)}^{-1} \]
      5. pow-flip99.7%

        \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot \color{blue}{{N}^{\left(-3\right)}}\right)}\right)}^{-1} \]
      6. metadata-eval99.7%

        \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{\color{blue}{-3}}\right)}\right)}^{-1} \]
    8. Applied egg-rr99.7%

      \[\leadsto \color{blue}{{\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right)}\right)}^{-1}} \]
    9. Step-by-step derivation
      1. unpow-199.7%

        \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right)}}} \]
      2. +-commutative99.7%

        \[\leadsto \frac{1}{\frac{N}{\color{blue}{\left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right) + 1}}} \]
      3. sub-neg99.7%

        \[\leadsto \frac{1}{\frac{N}{\color{blue}{\left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} + \left(-0.25 \cdot {N}^{-3}\right)\right)} + 1}} \]
      4. associate-+l+99.7%

        \[\leadsto \frac{1}{\frac{N}{\color{blue}{\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} + \left(\left(-0.25 \cdot {N}^{-3}\right) + 1\right)}}} \]
      5. +-commutative99.7%

        \[\leadsto \frac{1}{\frac{N}{\frac{\color{blue}{\frac{0.3333333333333333}{N} + -0.5}}{N} + \left(\left(-0.25 \cdot {N}^{-3}\right) + 1\right)}} \]
      6. distribute-lft-neg-in99.7%

        \[\leadsto \frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(\color{blue}{\left(-0.25\right) \cdot {N}^{-3}} + 1\right)}} \]
      7. metadata-eval99.7%

        \[\leadsto \frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(\color{blue}{-0.25} \cdot {N}^{-3} + 1\right)}} \]
    10. Simplified99.7%

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(-0.25 \cdot {N}^{-3} + 1\right)}}} \]
    11. Taylor expanded in N around -inf 99.7%

      \[\leadsto \frac{1}{\color{blue}{-1 \cdot \left(N \cdot \left(-1 \cdot \frac{0.5 + -1 \cdot \frac{0.08333333333333333 - 0.041666666666666664 \cdot \frac{1}{N}}{N}}{N} - 1\right)\right)}} \]
    12. Taylor expanded in N around inf 99.7%

      \[\leadsto \frac{1}{-1 \cdot \color{blue}{\left(N \cdot \left(\frac{0.08333333333333333}{{N}^{2}} - \left(1 + \left(0.5 \cdot \frac{1}{N} + 0.041666666666666664 \cdot \frac{1}{{N}^{3}}\right)\right)\right)\right)}} \]
    13. Step-by-step derivation
      1. associate-+r+99.7%

        \[\leadsto \frac{1}{-1 \cdot \left(N \cdot \left(\frac{0.08333333333333333}{{N}^{2}} - \color{blue}{\left(\left(1 + 0.5 \cdot \frac{1}{N}\right) + 0.041666666666666664 \cdot \frac{1}{{N}^{3}}\right)}\right)\right)} \]
      2. associate--r+99.7%

        \[\leadsto \frac{1}{-1 \cdot \left(N \cdot \color{blue}{\left(\left(\frac{0.08333333333333333}{{N}^{2}} - \left(1 + 0.5 \cdot \frac{1}{N}\right)\right) - 0.041666666666666664 \cdot \frac{1}{{N}^{3}}\right)}\right)} \]
    14. Simplified99.7%

      \[\leadsto \frac{1}{-1 \cdot \color{blue}{\left(N \cdot \left(\left(\frac{\frac{0.08333333333333333}{N} + -0.5}{N} - 1\right) - \frac{0.041666666666666664}{{N}^{3}}\right)\right)}} \]

    if 1e-3 < (-.f64 (log.f64 (+.f64 N #s(literal 1 binary64))) (log.f64 N))

    1. Initial program 90.7%

      \[\log \left(N + 1\right) - \log N \]
    2. Step-by-step derivation
      1. +-commutative90.7%

        \[\leadsto \log \color{blue}{\left(1 + N\right)} - \log N \]
      2. log1p-define91.0%

        \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right)} - \log N \]
    3. Simplified91.0%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right) - \log N} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. add-log-exp91.0%

        \[\leadsto \color{blue}{\log \left(e^{\mathsf{log1p}\left(N\right)}\right)} - \log N \]
      2. log1p-expm1-u90.8%

        \[\leadsto \log \left(e^{\mathsf{log1p}\left(N\right)}\right) - \color{blue}{\mathsf{log1p}\left(\mathsf{expm1}\left(\log N\right)\right)} \]
      3. log1p-undefine91.0%

        \[\leadsto \log \left(e^{\mathsf{log1p}\left(N\right)}\right) - \color{blue}{\log \left(1 + \mathsf{expm1}\left(\log N\right)\right)} \]
      4. diff-log90.6%

        \[\leadsto \color{blue}{\log \left(\frac{e^{\mathsf{log1p}\left(N\right)}}{1 + \mathsf{expm1}\left(\log N\right)}\right)} \]
      5. log1p-undefine90.3%

        \[\leadsto \log \left(\frac{e^{\color{blue}{\log \left(1 + N\right)}}}{1 + \mathsf{expm1}\left(\log N\right)}\right) \]
      6. rem-exp-log91.3%

        \[\leadsto \log \left(\frac{\color{blue}{1 + N}}{1 + \mathsf{expm1}\left(\log N\right)}\right) \]
      7. +-commutative91.3%

        \[\leadsto \log \left(\frac{\color{blue}{N + 1}}{1 + \mathsf{expm1}\left(\log N\right)}\right) \]
      8. add-exp-log91.6%

        \[\leadsto \log \left(\frac{N + 1}{\color{blue}{e^{\log \left(1 + \mathsf{expm1}\left(\log N\right)\right)}}}\right) \]
      9. log1p-undefine91.2%

        \[\leadsto \log \left(\frac{N + 1}{e^{\color{blue}{\mathsf{log1p}\left(\mathsf{expm1}\left(\log N\right)\right)}}}\right) \]
      10. log1p-expm1-u91.6%

        \[\leadsto \log \left(\frac{N + 1}{e^{\color{blue}{\log N}}}\right) \]
      11. add-exp-log94.2%

        \[\leadsto \log \left(\frac{N + 1}{\color{blue}{N}}\right) \]
    6. Applied egg-rr94.2%

      \[\leadsto \color{blue}{\log \left(\frac{N + 1}{N}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\log \left(N + 1\right) - \log N \leq 0.001:\\ \;\;\;\;\frac{1}{N \cdot \left(\frac{0.041666666666666664}{{N}^{3}} - \left(-1 + \frac{\frac{0.08333333333333333}{N} + -0.5}{N}\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\log \left(\frac{N + 1}{N}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 99.3% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;N \leq 920:\\ \;\;\;\;\log \left(\frac{N + 1}{N}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{-1}{N \cdot \left(-1 - \frac{\frac{\frac{0.041666666666666664}{N} + -0.08333333333333333}{N} + 0.5}{N}\right)}\\ \end{array} \end{array} \]
(FPCore (N)
 :precision binary64
 (if (<= N 920.0)
   (log (/ (+ N 1.0) N))
   (/
    -1.0
    (*
     N
     (-
      -1.0
      (/
       (+ (/ (+ (/ 0.041666666666666664 N) -0.08333333333333333) N) 0.5)
       N))))))
double code(double N) {
	double tmp;
	if (N <= 920.0) {
		tmp = log(((N + 1.0) / N));
	} else {
		tmp = -1.0 / (N * (-1.0 - (((((0.041666666666666664 / N) + -0.08333333333333333) / N) + 0.5) / N)));
	}
	return tmp;
}
real(8) function code(n)
    real(8), intent (in) :: n
    real(8) :: tmp
    if (n <= 920.0d0) then
        tmp = log(((n + 1.0d0) / n))
    else
        tmp = (-1.0d0) / (n * ((-1.0d0) - (((((0.041666666666666664d0 / n) + (-0.08333333333333333d0)) / n) + 0.5d0) / n)))
    end if
    code = tmp
end function
public static double code(double N) {
	double tmp;
	if (N <= 920.0) {
		tmp = Math.log(((N + 1.0) / N));
	} else {
		tmp = -1.0 / (N * (-1.0 - (((((0.041666666666666664 / N) + -0.08333333333333333) / N) + 0.5) / N)));
	}
	return tmp;
}
def code(N):
	tmp = 0
	if N <= 920.0:
		tmp = math.log(((N + 1.0) / N))
	else:
		tmp = -1.0 / (N * (-1.0 - (((((0.041666666666666664 / N) + -0.08333333333333333) / N) + 0.5) / N)))
	return tmp
function code(N)
	tmp = 0.0
	if (N <= 920.0)
		tmp = log(Float64(Float64(N + 1.0) / N));
	else
		tmp = Float64(-1.0 / Float64(N * Float64(-1.0 - Float64(Float64(Float64(Float64(Float64(0.041666666666666664 / N) + -0.08333333333333333) / N) + 0.5) / N))));
	end
	return tmp
end
function tmp_2 = code(N)
	tmp = 0.0;
	if (N <= 920.0)
		tmp = log(((N + 1.0) / N));
	else
		tmp = -1.0 / (N * (-1.0 - (((((0.041666666666666664 / N) + -0.08333333333333333) / N) + 0.5) / N)));
	end
	tmp_2 = tmp;
end
code[N_] := If[LessEqual[N, 920.0], N[Log[N[(N[(N + 1.0), $MachinePrecision] / N), $MachinePrecision]], $MachinePrecision], N[(-1.0 / N[(N * N[(-1.0 - N[(N[(N[(N[(N[(0.041666666666666664 / N), $MachinePrecision] + -0.08333333333333333), $MachinePrecision] / N), $MachinePrecision] + 0.5), $MachinePrecision] / N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;N \leq 920:\\
\;\;\;\;\log \left(\frac{N + 1}{N}\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{-1}{N \cdot \left(-1 - \frac{\frac{\frac{0.041666666666666664}{N} + -0.08333333333333333}{N} + 0.5}{N}\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if N < 920

    1. Initial program 90.7%

      \[\log \left(N + 1\right) - \log N \]
    2. Step-by-step derivation
      1. +-commutative90.7%

        \[\leadsto \log \color{blue}{\left(1 + N\right)} - \log N \]
      2. log1p-define91.0%

        \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right)} - \log N \]
    3. Simplified91.0%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right) - \log N} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. add-log-exp91.0%

        \[\leadsto \color{blue}{\log \left(e^{\mathsf{log1p}\left(N\right)}\right)} - \log N \]
      2. log1p-expm1-u90.8%

        \[\leadsto \log \left(e^{\mathsf{log1p}\left(N\right)}\right) - \color{blue}{\mathsf{log1p}\left(\mathsf{expm1}\left(\log N\right)\right)} \]
      3. log1p-undefine91.0%

        \[\leadsto \log \left(e^{\mathsf{log1p}\left(N\right)}\right) - \color{blue}{\log \left(1 + \mathsf{expm1}\left(\log N\right)\right)} \]
      4. diff-log90.6%

        \[\leadsto \color{blue}{\log \left(\frac{e^{\mathsf{log1p}\left(N\right)}}{1 + \mathsf{expm1}\left(\log N\right)}\right)} \]
      5. log1p-undefine90.3%

        \[\leadsto \log \left(\frac{e^{\color{blue}{\log \left(1 + N\right)}}}{1 + \mathsf{expm1}\left(\log N\right)}\right) \]
      6. rem-exp-log91.3%

        \[\leadsto \log \left(\frac{\color{blue}{1 + N}}{1 + \mathsf{expm1}\left(\log N\right)}\right) \]
      7. +-commutative91.3%

        \[\leadsto \log \left(\frac{\color{blue}{N + 1}}{1 + \mathsf{expm1}\left(\log N\right)}\right) \]
      8. add-exp-log91.6%

        \[\leadsto \log \left(\frac{N + 1}{\color{blue}{e^{\log \left(1 + \mathsf{expm1}\left(\log N\right)\right)}}}\right) \]
      9. log1p-undefine91.2%

        \[\leadsto \log \left(\frac{N + 1}{e^{\color{blue}{\mathsf{log1p}\left(\mathsf{expm1}\left(\log N\right)\right)}}}\right) \]
      10. log1p-expm1-u91.6%

        \[\leadsto \log \left(\frac{N + 1}{e^{\color{blue}{\log N}}}\right) \]
      11. add-exp-log94.2%

        \[\leadsto \log \left(\frac{N + 1}{\color{blue}{N}}\right) \]
    6. Applied egg-rr94.2%

      \[\leadsto \color{blue}{\log \left(\frac{N + 1}{N}\right)} \]

    if 920 < N

    1. Initial program 17.1%

      \[\log \left(N + 1\right) - \log N \]
    2. Step-by-step derivation
      1. +-commutative17.1%

        \[\leadsto \log \color{blue}{\left(1 + N\right)} - \log N \]
      2. log1p-define17.1%

        \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right)} - \log N \]
    3. Simplified17.1%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right) - \log N} \]
    4. Add Preprocessing
    5. Taylor expanded in N around inf 99.6%

      \[\leadsto \color{blue}{\frac{\left(1 + \frac{0.3333333333333333}{{N}^{2}}\right) - \left(0.5 \cdot \frac{1}{N} + 0.25 \cdot \frac{1}{{N}^{3}}\right)}{N}} \]
    6. Simplified99.6%

      \[\leadsto \color{blue}{\frac{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}{N}} \]
    7. Step-by-step derivation
      1. clear-num99.7%

        \[\leadsto \color{blue}{\frac{1}{\frac{N}{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}}} \]
      2. inv-pow99.7%

        \[\leadsto \color{blue}{{\left(\frac{N}{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}\right)}^{-1}} \]
      3. associate--l+99.7%

        \[\leadsto {\left(\frac{N}{\color{blue}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - \frac{0.25}{{N}^{3}}\right)}}\right)}^{-1} \]
      4. div-inv99.7%

        \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - \color{blue}{0.25 \cdot \frac{1}{{N}^{3}}}\right)}\right)}^{-1} \]
      5. pow-flip99.7%

        \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot \color{blue}{{N}^{\left(-3\right)}}\right)}\right)}^{-1} \]
      6. metadata-eval99.7%

        \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{\color{blue}{-3}}\right)}\right)}^{-1} \]
    8. Applied egg-rr99.7%

      \[\leadsto \color{blue}{{\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right)}\right)}^{-1}} \]
    9. Step-by-step derivation
      1. unpow-199.7%

        \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right)}}} \]
      2. +-commutative99.7%

        \[\leadsto \frac{1}{\frac{N}{\color{blue}{\left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right) + 1}}} \]
      3. sub-neg99.7%

        \[\leadsto \frac{1}{\frac{N}{\color{blue}{\left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} + \left(-0.25 \cdot {N}^{-3}\right)\right)} + 1}} \]
      4. associate-+l+99.7%

        \[\leadsto \frac{1}{\frac{N}{\color{blue}{\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} + \left(\left(-0.25 \cdot {N}^{-3}\right) + 1\right)}}} \]
      5. +-commutative99.7%

        \[\leadsto \frac{1}{\frac{N}{\frac{\color{blue}{\frac{0.3333333333333333}{N} + -0.5}}{N} + \left(\left(-0.25 \cdot {N}^{-3}\right) + 1\right)}} \]
      6. distribute-lft-neg-in99.7%

        \[\leadsto \frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(\color{blue}{\left(-0.25\right) \cdot {N}^{-3}} + 1\right)}} \]
      7. metadata-eval99.7%

        \[\leadsto \frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(\color{blue}{-0.25} \cdot {N}^{-3} + 1\right)}} \]
    10. Simplified99.7%

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(-0.25 \cdot {N}^{-3} + 1\right)}}} \]
    11. Taylor expanded in N around -inf 99.7%

      \[\leadsto \frac{1}{\color{blue}{-1 \cdot \left(N \cdot \left(-1 \cdot \frac{0.5 + -1 \cdot \frac{0.08333333333333333 - 0.041666666666666664 \cdot \frac{1}{N}}{N}}{N} - 1\right)\right)}} \]
    12. Taylor expanded in N around -inf 99.7%

      \[\leadsto \frac{1}{-1 \cdot \color{blue}{\left(-1 \cdot \left(N \cdot \left(1 + -1 \cdot \frac{-1 \cdot \frac{0.041666666666666664 \cdot \frac{1}{N} - 0.08333333333333333}{N} - 0.5}{N}\right)\right)\right)}} \]
    13. Step-by-step derivation
      1. associate-*r*99.7%

        \[\leadsto \frac{1}{-1 \cdot \color{blue}{\left(\left(-1 \cdot N\right) \cdot \left(1 + -1 \cdot \frac{-1 \cdot \frac{0.041666666666666664 \cdot \frac{1}{N} - 0.08333333333333333}{N} - 0.5}{N}\right)\right)}} \]
      2. neg-mul-199.7%

        \[\leadsto \frac{1}{-1 \cdot \left(\color{blue}{\left(-N\right)} \cdot \left(1 + -1 \cdot \frac{-1 \cdot \frac{0.041666666666666664 \cdot \frac{1}{N} - 0.08333333333333333}{N} - 0.5}{N}\right)\right)} \]
      3. associate-*r/99.7%

        \[\leadsto \frac{1}{-1 \cdot \left(\left(-N\right) \cdot \left(1 + \color{blue}{\frac{-1 \cdot \left(-1 \cdot \frac{0.041666666666666664 \cdot \frac{1}{N} - 0.08333333333333333}{N} - 0.5\right)}{N}}\right)\right)} \]
    14. Simplified99.7%

      \[\leadsto \frac{1}{-1 \cdot \color{blue}{\left(\left(-N\right) \cdot \left(1 + \frac{\frac{\frac{0.041666666666666664}{N} + -0.08333333333333333}{N} + 0.5}{N}\right)\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;N \leq 920:\\ \;\;\;\;\log \left(\frac{N + 1}{N}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{-1}{N \cdot \left(-1 - \frac{\frac{\frac{0.041666666666666664}{N} + -0.08333333333333333}{N} + 0.5}{N}\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 96.6% accurate, 10.8× speedup?

\[\begin{array}{l} \\ \frac{1}{N \cdot \left(1 + \frac{0.5 + \left(\frac{\frac{0.041666666666666664}{N}}{N} - \frac{0.08333333333333333}{N}\right)}{N}\right)} \end{array} \]
(FPCore (N)
 :precision binary64
 (/
  1.0
  (*
   N
   (+
    1.0
    (/
     (+ 0.5 (- (/ (/ 0.041666666666666664 N) N) (/ 0.08333333333333333 N)))
     N)))))
double code(double N) {
	return 1.0 / (N * (1.0 + ((0.5 + (((0.041666666666666664 / N) / N) - (0.08333333333333333 / N))) / N)));
}
real(8) function code(n)
    real(8), intent (in) :: n
    code = 1.0d0 / (n * (1.0d0 + ((0.5d0 + (((0.041666666666666664d0 / n) / n) - (0.08333333333333333d0 / n))) / n)))
end function
public static double code(double N) {
	return 1.0 / (N * (1.0 + ((0.5 + (((0.041666666666666664 / N) / N) - (0.08333333333333333 / N))) / N)));
}
def code(N):
	return 1.0 / (N * (1.0 + ((0.5 + (((0.041666666666666664 / N) / N) - (0.08333333333333333 / N))) / N)))
function code(N)
	return Float64(1.0 / Float64(N * Float64(1.0 + Float64(Float64(0.5 + Float64(Float64(Float64(0.041666666666666664 / N) / N) - Float64(0.08333333333333333 / N))) / N))))
end
function tmp = code(N)
	tmp = 1.0 / (N * (1.0 + ((0.5 + (((0.041666666666666664 / N) / N) - (0.08333333333333333 / N))) / N)));
end
code[N_] := N[(1.0 / N[(N * N[(1.0 + N[(N[(0.5 + N[(N[(N[(0.041666666666666664 / N), $MachinePrecision] / N), $MachinePrecision] - N[(0.08333333333333333 / N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{N \cdot \left(1 + \frac{0.5 + \left(\frac{\frac{0.041666666666666664}{N}}{N} - \frac{0.08333333333333333}{N}\right)}{N}\right)}
\end{array}
Derivation
  1. Initial program 23.4%

    \[\log \left(N + 1\right) - \log N \]
  2. Step-by-step derivation
    1. +-commutative23.4%

      \[\leadsto \log \color{blue}{\left(1 + N\right)} - \log N \]
    2. log1p-define23.4%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right)} - \log N \]
  3. Simplified23.4%

    \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right) - \log N} \]
  4. Add Preprocessing
  5. Taylor expanded in N around inf 96.0%

    \[\leadsto \color{blue}{\frac{\left(1 + \frac{0.3333333333333333}{{N}^{2}}\right) - \left(0.5 \cdot \frac{1}{N} + 0.25 \cdot \frac{1}{{N}^{3}}\right)}{N}} \]
  6. Simplified96.1%

    \[\leadsto \color{blue}{\frac{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}{N}} \]
  7. Step-by-step derivation
    1. clear-num96.1%

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}}} \]
    2. inv-pow96.1%

      \[\leadsto \color{blue}{{\left(\frac{N}{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}\right)}^{-1}} \]
    3. associate--l+96.1%

      \[\leadsto {\left(\frac{N}{\color{blue}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - \frac{0.25}{{N}^{3}}\right)}}\right)}^{-1} \]
    4. div-inv96.1%

      \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - \color{blue}{0.25 \cdot \frac{1}{{N}^{3}}}\right)}\right)}^{-1} \]
    5. pow-flip96.1%

      \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot \color{blue}{{N}^{\left(-3\right)}}\right)}\right)}^{-1} \]
    6. metadata-eval96.1%

      \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{\color{blue}{-3}}\right)}\right)}^{-1} \]
  8. Applied egg-rr96.1%

    \[\leadsto \color{blue}{{\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right)}\right)}^{-1}} \]
  9. Step-by-step derivation
    1. unpow-196.1%

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right)}}} \]
    2. +-commutative96.1%

      \[\leadsto \frac{1}{\frac{N}{\color{blue}{\left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right) + 1}}} \]
    3. sub-neg96.1%

      \[\leadsto \frac{1}{\frac{N}{\color{blue}{\left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} + \left(-0.25 \cdot {N}^{-3}\right)\right)} + 1}} \]
    4. associate-+l+96.1%

      \[\leadsto \frac{1}{\frac{N}{\color{blue}{\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} + \left(\left(-0.25 \cdot {N}^{-3}\right) + 1\right)}}} \]
    5. +-commutative96.1%

      \[\leadsto \frac{1}{\frac{N}{\frac{\color{blue}{\frac{0.3333333333333333}{N} + -0.5}}{N} + \left(\left(-0.25 \cdot {N}^{-3}\right) + 1\right)}} \]
    6. distribute-lft-neg-in96.1%

      \[\leadsto \frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(\color{blue}{\left(-0.25\right) \cdot {N}^{-3}} + 1\right)}} \]
    7. metadata-eval96.1%

      \[\leadsto \frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(\color{blue}{-0.25} \cdot {N}^{-3} + 1\right)}} \]
  10. Simplified96.1%

    \[\leadsto \color{blue}{\frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(-0.25 \cdot {N}^{-3} + 1\right)}}} \]
  11. Taylor expanded in N around -inf 96.5%

    \[\leadsto \frac{1}{\color{blue}{-1 \cdot \left(N \cdot \left(-1 \cdot \frac{0.5 + -1 \cdot \frac{0.08333333333333333 - 0.041666666666666664 \cdot \frac{1}{N}}{N}}{N} - 1\right)\right)}} \]
  12. Step-by-step derivation
    1. div-sub96.5%

      \[\leadsto \frac{1}{-1 \cdot \left(N \cdot \left(-1 \cdot \frac{0.5 + -1 \cdot \color{blue}{\left(\frac{0.08333333333333333}{N} - \frac{0.041666666666666664 \cdot \frac{1}{N}}{N}\right)}}{N} - 1\right)\right)} \]
    2. un-div-inv96.5%

      \[\leadsto \frac{1}{-1 \cdot \left(N \cdot \left(-1 \cdot \frac{0.5 + -1 \cdot \left(\frac{0.08333333333333333}{N} - \frac{\color{blue}{\frac{0.041666666666666664}{N}}}{N}\right)}{N} - 1\right)\right)} \]
  13. Applied egg-rr96.5%

    \[\leadsto \frac{1}{-1 \cdot \left(N \cdot \left(-1 \cdot \frac{0.5 + -1 \cdot \color{blue}{\left(\frac{0.08333333333333333}{N} - \frac{\frac{0.041666666666666664}{N}}{N}\right)}}{N} - 1\right)\right)} \]
  14. Final simplification96.5%

    \[\leadsto \frac{1}{N \cdot \left(1 + \frac{0.5 + \left(\frac{\frac{0.041666666666666664}{N}}{N} - \frac{0.08333333333333333}{N}\right)}{N}\right)} \]
  15. Add Preprocessing

Alternative 4: 96.6% accurate, 12.1× speedup?

\[\begin{array}{l} \\ \frac{-1}{N \cdot \left(-1 - \frac{\frac{\frac{0.041666666666666664}{N} + -0.08333333333333333}{N} + 0.5}{N}\right)} \end{array} \]
(FPCore (N)
 :precision binary64
 (/
  -1.0
  (*
   N
   (-
    -1.0
    (/ (+ (/ (+ (/ 0.041666666666666664 N) -0.08333333333333333) N) 0.5) N)))))
double code(double N) {
	return -1.0 / (N * (-1.0 - (((((0.041666666666666664 / N) + -0.08333333333333333) / N) + 0.5) / N)));
}
real(8) function code(n)
    real(8), intent (in) :: n
    code = (-1.0d0) / (n * ((-1.0d0) - (((((0.041666666666666664d0 / n) + (-0.08333333333333333d0)) / n) + 0.5d0) / n)))
end function
public static double code(double N) {
	return -1.0 / (N * (-1.0 - (((((0.041666666666666664 / N) + -0.08333333333333333) / N) + 0.5) / N)));
}
def code(N):
	return -1.0 / (N * (-1.0 - (((((0.041666666666666664 / N) + -0.08333333333333333) / N) + 0.5) / N)))
function code(N)
	return Float64(-1.0 / Float64(N * Float64(-1.0 - Float64(Float64(Float64(Float64(Float64(0.041666666666666664 / N) + -0.08333333333333333) / N) + 0.5) / N))))
end
function tmp = code(N)
	tmp = -1.0 / (N * (-1.0 - (((((0.041666666666666664 / N) + -0.08333333333333333) / N) + 0.5) / N)));
end
code[N_] := N[(-1.0 / N[(N * N[(-1.0 - N[(N[(N[(N[(N[(0.041666666666666664 / N), $MachinePrecision] + -0.08333333333333333), $MachinePrecision] / N), $MachinePrecision] + 0.5), $MachinePrecision] / N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-1}{N \cdot \left(-1 - \frac{\frac{\frac{0.041666666666666664}{N} + -0.08333333333333333}{N} + 0.5}{N}\right)}
\end{array}
Derivation
  1. Initial program 23.4%

    \[\log \left(N + 1\right) - \log N \]
  2. Step-by-step derivation
    1. +-commutative23.4%

      \[\leadsto \log \color{blue}{\left(1 + N\right)} - \log N \]
    2. log1p-define23.4%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right)} - \log N \]
  3. Simplified23.4%

    \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right) - \log N} \]
  4. Add Preprocessing
  5. Taylor expanded in N around inf 96.0%

    \[\leadsto \color{blue}{\frac{\left(1 + \frac{0.3333333333333333}{{N}^{2}}\right) - \left(0.5 \cdot \frac{1}{N} + 0.25 \cdot \frac{1}{{N}^{3}}\right)}{N}} \]
  6. Simplified96.1%

    \[\leadsto \color{blue}{\frac{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}{N}} \]
  7. Step-by-step derivation
    1. clear-num96.1%

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}}} \]
    2. inv-pow96.1%

      \[\leadsto \color{blue}{{\left(\frac{N}{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}\right)}^{-1}} \]
    3. associate--l+96.1%

      \[\leadsto {\left(\frac{N}{\color{blue}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - \frac{0.25}{{N}^{3}}\right)}}\right)}^{-1} \]
    4. div-inv96.1%

      \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - \color{blue}{0.25 \cdot \frac{1}{{N}^{3}}}\right)}\right)}^{-1} \]
    5. pow-flip96.1%

      \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot \color{blue}{{N}^{\left(-3\right)}}\right)}\right)}^{-1} \]
    6. metadata-eval96.1%

      \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{\color{blue}{-3}}\right)}\right)}^{-1} \]
  8. Applied egg-rr96.1%

    \[\leadsto \color{blue}{{\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right)}\right)}^{-1}} \]
  9. Step-by-step derivation
    1. unpow-196.1%

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right)}}} \]
    2. +-commutative96.1%

      \[\leadsto \frac{1}{\frac{N}{\color{blue}{\left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right) + 1}}} \]
    3. sub-neg96.1%

      \[\leadsto \frac{1}{\frac{N}{\color{blue}{\left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} + \left(-0.25 \cdot {N}^{-3}\right)\right)} + 1}} \]
    4. associate-+l+96.1%

      \[\leadsto \frac{1}{\frac{N}{\color{blue}{\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} + \left(\left(-0.25 \cdot {N}^{-3}\right) + 1\right)}}} \]
    5. +-commutative96.1%

      \[\leadsto \frac{1}{\frac{N}{\frac{\color{blue}{\frac{0.3333333333333333}{N} + -0.5}}{N} + \left(\left(-0.25 \cdot {N}^{-3}\right) + 1\right)}} \]
    6. distribute-lft-neg-in96.1%

      \[\leadsto \frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(\color{blue}{\left(-0.25\right) \cdot {N}^{-3}} + 1\right)}} \]
    7. metadata-eval96.1%

      \[\leadsto \frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(\color{blue}{-0.25} \cdot {N}^{-3} + 1\right)}} \]
  10. Simplified96.1%

    \[\leadsto \color{blue}{\frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(-0.25 \cdot {N}^{-3} + 1\right)}}} \]
  11. Taylor expanded in N around -inf 96.5%

    \[\leadsto \frac{1}{\color{blue}{-1 \cdot \left(N \cdot \left(-1 \cdot \frac{0.5 + -1 \cdot \frac{0.08333333333333333 - 0.041666666666666664 \cdot \frac{1}{N}}{N}}{N} - 1\right)\right)}} \]
  12. Taylor expanded in N around -inf 96.5%

    \[\leadsto \frac{1}{-1 \cdot \color{blue}{\left(-1 \cdot \left(N \cdot \left(1 + -1 \cdot \frac{-1 \cdot \frac{0.041666666666666664 \cdot \frac{1}{N} - 0.08333333333333333}{N} - 0.5}{N}\right)\right)\right)}} \]
  13. Step-by-step derivation
    1. associate-*r*96.5%

      \[\leadsto \frac{1}{-1 \cdot \color{blue}{\left(\left(-1 \cdot N\right) \cdot \left(1 + -1 \cdot \frac{-1 \cdot \frac{0.041666666666666664 \cdot \frac{1}{N} - 0.08333333333333333}{N} - 0.5}{N}\right)\right)}} \]
    2. neg-mul-196.5%

      \[\leadsto \frac{1}{-1 \cdot \left(\color{blue}{\left(-N\right)} \cdot \left(1 + -1 \cdot \frac{-1 \cdot \frac{0.041666666666666664 \cdot \frac{1}{N} - 0.08333333333333333}{N} - 0.5}{N}\right)\right)} \]
    3. associate-*r/96.5%

      \[\leadsto \frac{1}{-1 \cdot \left(\left(-N\right) \cdot \left(1 + \color{blue}{\frac{-1 \cdot \left(-1 \cdot \frac{0.041666666666666664 \cdot \frac{1}{N} - 0.08333333333333333}{N} - 0.5\right)}{N}}\right)\right)} \]
  14. Simplified96.5%

    \[\leadsto \frac{1}{-1 \cdot \color{blue}{\left(\left(-N\right) \cdot \left(1 + \frac{\frac{\frac{0.041666666666666664}{N} + -0.08333333333333333}{N} + 0.5}{N}\right)\right)}} \]
  15. Final simplification96.5%

    \[\leadsto \frac{-1}{N \cdot \left(-1 - \frac{\frac{\frac{0.041666666666666664}{N} + -0.08333333333333333}{N} + 0.5}{N}\right)} \]
  16. Add Preprocessing

Alternative 5: 96.2% accurate, 13.7× speedup?

\[\begin{array}{l} \\ \frac{\frac{-0.5 + \frac{0.3333333333333333 + \frac{-0.25}{N}}{N}}{N} - -1}{N} \end{array} \]
(FPCore (N)
 :precision binary64
 (/ (- (/ (+ -0.5 (/ (+ 0.3333333333333333 (/ -0.25 N)) N)) N) -1.0) N))
double code(double N) {
	return (((-0.5 + ((0.3333333333333333 + (-0.25 / N)) / N)) / N) - -1.0) / N;
}
real(8) function code(n)
    real(8), intent (in) :: n
    code = ((((-0.5d0) + ((0.3333333333333333d0 + ((-0.25d0) / n)) / n)) / n) - (-1.0d0)) / n
end function
public static double code(double N) {
	return (((-0.5 + ((0.3333333333333333 + (-0.25 / N)) / N)) / N) - -1.0) / N;
}
def code(N):
	return (((-0.5 + ((0.3333333333333333 + (-0.25 / N)) / N)) / N) - -1.0) / N
function code(N)
	return Float64(Float64(Float64(Float64(-0.5 + Float64(Float64(0.3333333333333333 + Float64(-0.25 / N)) / N)) / N) - -1.0) / N)
end
function tmp = code(N)
	tmp = (((-0.5 + ((0.3333333333333333 + (-0.25 / N)) / N)) / N) - -1.0) / N;
end
code[N_] := N[(N[(N[(N[(-0.5 + N[(N[(0.3333333333333333 + N[(-0.25 / N), $MachinePrecision]), $MachinePrecision] / N), $MachinePrecision]), $MachinePrecision] / N), $MachinePrecision] - -1.0), $MachinePrecision] / N), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{-0.5 + \frac{0.3333333333333333 + \frac{-0.25}{N}}{N}}{N} - -1}{N}
\end{array}
Derivation
  1. Initial program 23.4%

    \[\log \left(N + 1\right) - \log N \]
  2. Step-by-step derivation
    1. +-commutative23.4%

      \[\leadsto \log \color{blue}{\left(1 + N\right)} - \log N \]
    2. log1p-define23.4%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right)} - \log N \]
  3. Simplified23.4%

    \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right) - \log N} \]
  4. Add Preprocessing
  5. Taylor expanded in N around -inf 96.1%

    \[\leadsto \color{blue}{-1 \cdot \frac{-1 \cdot \frac{-1 \cdot \frac{0.25 \cdot \frac{1}{N} - 0.3333333333333333}{N} - 0.5}{N} - 1}{N}} \]
  6. Step-by-step derivation
    1. mul-1-neg96.1%

      \[\leadsto \color{blue}{-\frac{-1 \cdot \frac{-1 \cdot \frac{0.25 \cdot \frac{1}{N} - 0.3333333333333333}{N} - 0.5}{N} - 1}{N}} \]
    2. distribute-neg-frac296.1%

      \[\leadsto \color{blue}{\frac{-1 \cdot \frac{-1 \cdot \frac{0.25 \cdot \frac{1}{N} - 0.3333333333333333}{N} - 0.5}{N} - 1}{-N}} \]
  7. Simplified96.1%

    \[\leadsto \color{blue}{\frac{-1 - \frac{-0.5 + \frac{0.3333333333333333 + \frac{-0.25}{N}}{N}}{N}}{-N}} \]
  8. Final simplification96.1%

    \[\leadsto \frac{\frac{-0.5 + \frac{0.3333333333333333 + \frac{-0.25}{N}}{N}}{N} - -1}{N} \]
  9. Add Preprocessing

Alternative 6: 95.4% accurate, 15.8× speedup?

\[\begin{array}{l} \\ \frac{-1}{N \cdot \left(-1 + \frac{\frac{0.08333333333333333}{N} + -0.5}{N}\right)} \end{array} \]
(FPCore (N)
 :precision binary64
 (/ -1.0 (* N (+ -1.0 (/ (+ (/ 0.08333333333333333 N) -0.5) N)))))
double code(double N) {
	return -1.0 / (N * (-1.0 + (((0.08333333333333333 / N) + -0.5) / N)));
}
real(8) function code(n)
    real(8), intent (in) :: n
    code = (-1.0d0) / (n * ((-1.0d0) + (((0.08333333333333333d0 / n) + (-0.5d0)) / n)))
end function
public static double code(double N) {
	return -1.0 / (N * (-1.0 + (((0.08333333333333333 / N) + -0.5) / N)));
}
def code(N):
	return -1.0 / (N * (-1.0 + (((0.08333333333333333 / N) + -0.5) / N)))
function code(N)
	return Float64(-1.0 / Float64(N * Float64(-1.0 + Float64(Float64(Float64(0.08333333333333333 / N) + -0.5) / N))))
end
function tmp = code(N)
	tmp = -1.0 / (N * (-1.0 + (((0.08333333333333333 / N) + -0.5) / N)));
end
code[N_] := N[(-1.0 / N[(N * N[(-1.0 + N[(N[(N[(0.08333333333333333 / N), $MachinePrecision] + -0.5), $MachinePrecision] / N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-1}{N \cdot \left(-1 + \frac{\frac{0.08333333333333333}{N} + -0.5}{N}\right)}
\end{array}
Derivation
  1. Initial program 23.4%

    \[\log \left(N + 1\right) - \log N \]
  2. Step-by-step derivation
    1. +-commutative23.4%

      \[\leadsto \log \color{blue}{\left(1 + N\right)} - \log N \]
    2. log1p-define23.4%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right)} - \log N \]
  3. Simplified23.4%

    \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right) - \log N} \]
  4. Add Preprocessing
  5. Taylor expanded in N around inf 96.0%

    \[\leadsto \color{blue}{\frac{\left(1 + \frac{0.3333333333333333}{{N}^{2}}\right) - \left(0.5 \cdot \frac{1}{N} + 0.25 \cdot \frac{1}{{N}^{3}}\right)}{N}} \]
  6. Simplified96.1%

    \[\leadsto \color{blue}{\frac{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}{N}} \]
  7. Step-by-step derivation
    1. clear-num96.1%

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}}} \]
    2. inv-pow96.1%

      \[\leadsto \color{blue}{{\left(\frac{N}{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}\right)}^{-1}} \]
    3. associate--l+96.1%

      \[\leadsto {\left(\frac{N}{\color{blue}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - \frac{0.25}{{N}^{3}}\right)}}\right)}^{-1} \]
    4. div-inv96.1%

      \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - \color{blue}{0.25 \cdot \frac{1}{{N}^{3}}}\right)}\right)}^{-1} \]
    5. pow-flip96.1%

      \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot \color{blue}{{N}^{\left(-3\right)}}\right)}\right)}^{-1} \]
    6. metadata-eval96.1%

      \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{\color{blue}{-3}}\right)}\right)}^{-1} \]
  8. Applied egg-rr96.1%

    \[\leadsto \color{blue}{{\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right)}\right)}^{-1}} \]
  9. Step-by-step derivation
    1. unpow-196.1%

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right)}}} \]
    2. +-commutative96.1%

      \[\leadsto \frac{1}{\frac{N}{\color{blue}{\left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right) + 1}}} \]
    3. sub-neg96.1%

      \[\leadsto \frac{1}{\frac{N}{\color{blue}{\left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} + \left(-0.25 \cdot {N}^{-3}\right)\right)} + 1}} \]
    4. associate-+l+96.1%

      \[\leadsto \frac{1}{\frac{N}{\color{blue}{\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} + \left(\left(-0.25 \cdot {N}^{-3}\right) + 1\right)}}} \]
    5. +-commutative96.1%

      \[\leadsto \frac{1}{\frac{N}{\frac{\color{blue}{\frac{0.3333333333333333}{N} + -0.5}}{N} + \left(\left(-0.25 \cdot {N}^{-3}\right) + 1\right)}} \]
    6. distribute-lft-neg-in96.1%

      \[\leadsto \frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(\color{blue}{\left(-0.25\right) \cdot {N}^{-3}} + 1\right)}} \]
    7. metadata-eval96.1%

      \[\leadsto \frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(\color{blue}{-0.25} \cdot {N}^{-3} + 1\right)}} \]
  10. Simplified96.1%

    \[\leadsto \color{blue}{\frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(-0.25 \cdot {N}^{-3} + 1\right)}}} \]
  11. Taylor expanded in N around -inf 96.5%

    \[\leadsto \frac{1}{\color{blue}{-1 \cdot \left(N \cdot \left(-1 \cdot \frac{0.5 + -1 \cdot \frac{0.08333333333333333 - 0.041666666666666664 \cdot \frac{1}{N}}{N}}{N} - 1\right)\right)}} \]
  12. Taylor expanded in N around inf 94.9%

    \[\leadsto \frac{1}{-1 \cdot \color{blue}{\left(N \cdot \left(\frac{0.08333333333333333}{{N}^{2}} - \left(1 + 0.5 \cdot \frac{1}{N}\right)\right)\right)}} \]
  13. Step-by-step derivation
    1. +-commutative94.9%

      \[\leadsto \frac{1}{-1 \cdot \left(N \cdot \left(\frac{0.08333333333333333}{{N}^{2}} - \color{blue}{\left(0.5 \cdot \frac{1}{N} + 1\right)}\right)\right)} \]
    2. associate--r+94.9%

      \[\leadsto \frac{1}{-1 \cdot \left(N \cdot \color{blue}{\left(\left(\frac{0.08333333333333333}{{N}^{2}} - 0.5 \cdot \frac{1}{N}\right) - 1\right)}\right)} \]
    3. unpow294.9%

      \[\leadsto \frac{1}{-1 \cdot \left(N \cdot \left(\left(\frac{0.08333333333333333}{\color{blue}{N \cdot N}} - 0.5 \cdot \frac{1}{N}\right) - 1\right)\right)} \]
    4. associate-/r*94.9%

      \[\leadsto \frac{1}{-1 \cdot \left(N \cdot \left(\left(\color{blue}{\frac{\frac{0.08333333333333333}{N}}{N}} - 0.5 \cdot \frac{1}{N}\right) - 1\right)\right)} \]
    5. metadata-eval94.9%

      \[\leadsto \frac{1}{-1 \cdot \left(N \cdot \left(\left(\frac{\frac{\color{blue}{0.08333333333333333 \cdot 1}}{N}}{N} - 0.5 \cdot \frac{1}{N}\right) - 1\right)\right)} \]
    6. associate-*r/94.9%

      \[\leadsto \frac{1}{-1 \cdot \left(N \cdot \left(\left(\frac{\color{blue}{0.08333333333333333 \cdot \frac{1}{N}}}{N} - 0.5 \cdot \frac{1}{N}\right) - 1\right)\right)} \]
    7. associate-*r/94.9%

      \[\leadsto \frac{1}{-1 \cdot \left(N \cdot \left(\left(\frac{0.08333333333333333 \cdot \frac{1}{N}}{N} - \color{blue}{\frac{0.5 \cdot 1}{N}}\right) - 1\right)\right)} \]
    8. metadata-eval94.9%

      \[\leadsto \frac{1}{-1 \cdot \left(N \cdot \left(\left(\frac{0.08333333333333333 \cdot \frac{1}{N}}{N} - \frac{\color{blue}{0.5}}{N}\right) - 1\right)\right)} \]
    9. div-sub94.9%

      \[\leadsto \frac{1}{-1 \cdot \left(N \cdot \left(\color{blue}{\frac{0.08333333333333333 \cdot \frac{1}{N} - 0.5}{N}} - 1\right)\right)} \]
    10. sub-neg94.9%

      \[\leadsto \frac{1}{-1 \cdot \left(N \cdot \left(\frac{\color{blue}{0.08333333333333333 \cdot \frac{1}{N} + \left(-0.5\right)}}{N} - 1\right)\right)} \]
    11. associate-*r/94.9%

      \[\leadsto \frac{1}{-1 \cdot \left(N \cdot \left(\frac{\color{blue}{\frac{0.08333333333333333 \cdot 1}{N}} + \left(-0.5\right)}{N} - 1\right)\right)} \]
    12. metadata-eval94.9%

      \[\leadsto \frac{1}{-1 \cdot \left(N \cdot \left(\frac{\frac{\color{blue}{0.08333333333333333}}{N} + \left(-0.5\right)}{N} - 1\right)\right)} \]
    13. metadata-eval94.9%

      \[\leadsto \frac{1}{-1 \cdot \left(N \cdot \left(\frac{\frac{0.08333333333333333}{N} + \color{blue}{-0.5}}{N} - 1\right)\right)} \]
  14. Simplified94.9%

    \[\leadsto \frac{1}{-1 \cdot \color{blue}{\left(N \cdot \left(\frac{\frac{0.08333333333333333}{N} + -0.5}{N} - 1\right)\right)}} \]
  15. Final simplification94.9%

    \[\leadsto \frac{-1}{N \cdot \left(-1 + \frac{\frac{0.08333333333333333}{N} + -0.5}{N}\right)} \]
  16. Add Preprocessing

Alternative 7: 94.9% accurate, 18.6× speedup?

\[\begin{array}{l} \\ \frac{1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}}{N} \end{array} \]
(FPCore (N)
 :precision binary64
 (/ (+ 1.0 (/ (+ -0.5 (/ 0.3333333333333333 N)) N)) N))
double code(double N) {
	return (1.0 + ((-0.5 + (0.3333333333333333 / N)) / N)) / N;
}
real(8) function code(n)
    real(8), intent (in) :: n
    code = (1.0d0 + (((-0.5d0) + (0.3333333333333333d0 / n)) / n)) / n
end function
public static double code(double N) {
	return (1.0 + ((-0.5 + (0.3333333333333333 / N)) / N)) / N;
}
def code(N):
	return (1.0 + ((-0.5 + (0.3333333333333333 / N)) / N)) / N
function code(N)
	return Float64(Float64(1.0 + Float64(Float64(-0.5 + Float64(0.3333333333333333 / N)) / N)) / N)
end
function tmp = code(N)
	tmp = (1.0 + ((-0.5 + (0.3333333333333333 / N)) / N)) / N;
end
code[N_] := N[(N[(1.0 + N[(N[(-0.5 + N[(0.3333333333333333 / N), $MachinePrecision]), $MachinePrecision] / N), $MachinePrecision]), $MachinePrecision] / N), $MachinePrecision]
\begin{array}{l}

\\
\frac{1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}}{N}
\end{array}
Derivation
  1. Initial program 23.4%

    \[\log \left(N + 1\right) - \log N \]
  2. Step-by-step derivation
    1. +-commutative23.4%

      \[\leadsto \log \color{blue}{\left(1 + N\right)} - \log N \]
    2. log1p-define23.4%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right)} - \log N \]
  3. Simplified23.4%

    \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right) - \log N} \]
  4. Add Preprocessing
  5. Taylor expanded in N around inf 94.4%

    \[\leadsto \color{blue}{\frac{\left(1 + \frac{0.3333333333333333}{{N}^{2}}\right) - 0.5 \cdot \frac{1}{N}}{N}} \]
  6. Step-by-step derivation
    1. associate--l+94.4%

      \[\leadsto \frac{\color{blue}{1 + \left(\frac{0.3333333333333333}{{N}^{2}} - 0.5 \cdot \frac{1}{N}\right)}}{N} \]
    2. unpow294.4%

      \[\leadsto \frac{1 + \left(\frac{0.3333333333333333}{\color{blue}{N \cdot N}} - 0.5 \cdot \frac{1}{N}\right)}{N} \]
    3. associate-/r*94.4%

      \[\leadsto \frac{1 + \left(\color{blue}{\frac{\frac{0.3333333333333333}{N}}{N}} - 0.5 \cdot \frac{1}{N}\right)}{N} \]
    4. metadata-eval94.4%

      \[\leadsto \frac{1 + \left(\frac{\frac{\color{blue}{0.3333333333333333 \cdot 1}}{N}}{N} - 0.5 \cdot \frac{1}{N}\right)}{N} \]
    5. associate-*r/94.4%

      \[\leadsto \frac{1 + \left(\frac{\color{blue}{0.3333333333333333 \cdot \frac{1}{N}}}{N} - 0.5 \cdot \frac{1}{N}\right)}{N} \]
    6. associate-*r/94.4%

      \[\leadsto \frac{1 + \left(\frac{0.3333333333333333 \cdot \frac{1}{N}}{N} - \color{blue}{\frac{0.5 \cdot 1}{N}}\right)}{N} \]
    7. metadata-eval94.4%

      \[\leadsto \frac{1 + \left(\frac{0.3333333333333333 \cdot \frac{1}{N}}{N} - \frac{\color{blue}{0.5}}{N}\right)}{N} \]
    8. div-sub94.4%

      \[\leadsto \frac{1 + \color{blue}{\frac{0.3333333333333333 \cdot \frac{1}{N} - 0.5}{N}}}{N} \]
    9. sub-neg94.4%

      \[\leadsto \frac{1 + \frac{\color{blue}{0.3333333333333333 \cdot \frac{1}{N} + \left(-0.5\right)}}{N}}{N} \]
    10. metadata-eval94.4%

      \[\leadsto \frac{1 + \frac{0.3333333333333333 \cdot \frac{1}{N} + \color{blue}{-0.5}}{N}}{N} \]
    11. +-commutative94.4%

      \[\leadsto \frac{1 + \frac{\color{blue}{-0.5 + 0.3333333333333333 \cdot \frac{1}{N}}}{N}}{N} \]
    12. associate-*r/94.4%

      \[\leadsto \frac{1 + \frac{-0.5 + \color{blue}{\frac{0.3333333333333333 \cdot 1}{N}}}{N}}{N} \]
    13. metadata-eval94.4%

      \[\leadsto \frac{1 + \frac{-0.5 + \frac{\color{blue}{0.3333333333333333}}{N}}{N}}{N} \]
  7. Simplified94.4%

    \[\leadsto \color{blue}{\frac{1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}}{N}} \]
  8. Final simplification94.4%

    \[\leadsto \frac{1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}}{N} \]
  9. Add Preprocessing

Alternative 8: 92.9% accurate, 41.0× speedup?

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

\\
\frac{1}{N + 0.5}
\end{array}
Derivation
  1. Initial program 23.4%

    \[\log \left(N + 1\right) - \log N \]
  2. Step-by-step derivation
    1. +-commutative23.4%

      \[\leadsto \log \color{blue}{\left(1 + N\right)} - \log N \]
    2. log1p-define23.4%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right)} - \log N \]
  3. Simplified23.4%

    \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right) - \log N} \]
  4. Add Preprocessing
  5. Taylor expanded in N around inf 96.0%

    \[\leadsto \color{blue}{\frac{\left(1 + \frac{0.3333333333333333}{{N}^{2}}\right) - \left(0.5 \cdot \frac{1}{N} + 0.25 \cdot \frac{1}{{N}^{3}}\right)}{N}} \]
  6. Simplified96.1%

    \[\leadsto \color{blue}{\frac{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}{N}} \]
  7. Step-by-step derivation
    1. clear-num96.1%

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}}} \]
    2. inv-pow96.1%

      \[\leadsto \color{blue}{{\left(\frac{N}{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}\right)}^{-1}} \]
    3. associate--l+96.1%

      \[\leadsto {\left(\frac{N}{\color{blue}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - \frac{0.25}{{N}^{3}}\right)}}\right)}^{-1} \]
    4. div-inv96.1%

      \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - \color{blue}{0.25 \cdot \frac{1}{{N}^{3}}}\right)}\right)}^{-1} \]
    5. pow-flip96.1%

      \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot \color{blue}{{N}^{\left(-3\right)}}\right)}\right)}^{-1} \]
    6. metadata-eval96.1%

      \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{\color{blue}{-3}}\right)}\right)}^{-1} \]
  8. Applied egg-rr96.1%

    \[\leadsto \color{blue}{{\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right)}\right)}^{-1}} \]
  9. Step-by-step derivation
    1. unpow-196.1%

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right)}}} \]
    2. +-commutative96.1%

      \[\leadsto \frac{1}{\frac{N}{\color{blue}{\left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right) + 1}}} \]
    3. sub-neg96.1%

      \[\leadsto \frac{1}{\frac{N}{\color{blue}{\left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} + \left(-0.25 \cdot {N}^{-3}\right)\right)} + 1}} \]
    4. associate-+l+96.1%

      \[\leadsto \frac{1}{\frac{N}{\color{blue}{\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} + \left(\left(-0.25 \cdot {N}^{-3}\right) + 1\right)}}} \]
    5. +-commutative96.1%

      \[\leadsto \frac{1}{\frac{N}{\frac{\color{blue}{\frac{0.3333333333333333}{N} + -0.5}}{N} + \left(\left(-0.25 \cdot {N}^{-3}\right) + 1\right)}} \]
    6. distribute-lft-neg-in96.1%

      \[\leadsto \frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(\color{blue}{\left(-0.25\right) \cdot {N}^{-3}} + 1\right)}} \]
    7. metadata-eval96.1%

      \[\leadsto \frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(\color{blue}{-0.25} \cdot {N}^{-3} + 1\right)}} \]
  10. Simplified96.1%

    \[\leadsto \color{blue}{\frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(-0.25 \cdot {N}^{-3} + 1\right)}}} \]
  11. Taylor expanded in N around inf 92.3%

    \[\leadsto \frac{1}{\color{blue}{N \cdot \left(1 + 0.5 \cdot \frac{1}{N}\right)}} \]
  12. Step-by-step derivation
    1. distribute-lft-in92.4%

      \[\leadsto \frac{1}{\color{blue}{N \cdot 1 + N \cdot \left(0.5 \cdot \frac{1}{N}\right)}} \]
    2. *-rgt-identity92.4%

      \[\leadsto \frac{1}{\color{blue}{N} + N \cdot \left(0.5 \cdot \frac{1}{N}\right)} \]
    3. associate-*r/92.4%

      \[\leadsto \frac{1}{N + N \cdot \color{blue}{\frac{0.5 \cdot 1}{N}}} \]
    4. metadata-eval92.4%

      \[\leadsto \frac{1}{N + N \cdot \frac{\color{blue}{0.5}}{N}} \]
    5. associate-*r/92.4%

      \[\leadsto \frac{1}{N + \color{blue}{\frac{N \cdot 0.5}{N}}} \]
    6. *-commutative92.4%

      \[\leadsto \frac{1}{N + \frac{\color{blue}{0.5 \cdot N}}{N}} \]
    7. associate-*r/92.4%

      \[\leadsto \frac{1}{N + \color{blue}{0.5 \cdot \frac{N}{N}}} \]
    8. *-inverses92.4%

      \[\leadsto \frac{1}{N + 0.5 \cdot \color{blue}{1}} \]
    9. metadata-eval92.4%

      \[\leadsto \frac{1}{N + \color{blue}{0.5}} \]
  13. Simplified92.4%

    \[\leadsto \frac{1}{\color{blue}{N + 0.5}} \]
  14. Final simplification92.4%

    \[\leadsto \frac{1}{N + 0.5} \]
  15. Add Preprocessing

Alternative 9: 84.6% accurate, 68.3× speedup?

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

\\
\frac{1}{N}
\end{array}
Derivation
  1. Initial program 23.4%

    \[\log \left(N + 1\right) - \log N \]
  2. Step-by-step derivation
    1. +-commutative23.4%

      \[\leadsto \log \color{blue}{\left(1 + N\right)} - \log N \]
    2. log1p-define23.4%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right)} - \log N \]
  3. Simplified23.4%

    \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right) - \log N} \]
  4. Add Preprocessing
  5. Taylor expanded in N around inf 85.0%

    \[\leadsto \color{blue}{\frac{1}{N}} \]
  6. Final simplification85.0%

    \[\leadsto \frac{1}{N} \]
  7. Add Preprocessing

Alternative 10: 9.9% accurate, 205.0× speedup?

\[\begin{array}{l} \\ 2 \end{array} \]
(FPCore (N) :precision binary64 2.0)
double code(double N) {
	return 2.0;
}
real(8) function code(n)
    real(8), intent (in) :: n
    code = 2.0d0
end function
public static double code(double N) {
	return 2.0;
}
def code(N):
	return 2.0
function code(N)
	return 2.0
end
function tmp = code(N)
	tmp = 2.0;
end
code[N_] := 2.0
\begin{array}{l}

\\
2
\end{array}
Derivation
  1. Initial program 23.4%

    \[\log \left(N + 1\right) - \log N \]
  2. Step-by-step derivation
    1. +-commutative23.4%

      \[\leadsto \log \color{blue}{\left(1 + N\right)} - \log N \]
    2. log1p-define23.4%

      \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right)} - \log N \]
  3. Simplified23.4%

    \[\leadsto \color{blue}{\mathsf{log1p}\left(N\right) - \log N} \]
  4. Add Preprocessing
  5. Taylor expanded in N around inf 96.0%

    \[\leadsto \color{blue}{\frac{\left(1 + \frac{0.3333333333333333}{{N}^{2}}\right) - \left(0.5 \cdot \frac{1}{N} + 0.25 \cdot \frac{1}{{N}^{3}}\right)}{N}} \]
  6. Simplified96.1%

    \[\leadsto \color{blue}{\frac{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}{N}} \]
  7. Step-by-step derivation
    1. clear-num96.1%

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}}} \]
    2. inv-pow96.1%

      \[\leadsto \color{blue}{{\left(\frac{N}{\left(1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}\right) - \frac{0.25}{{N}^{3}}}\right)}^{-1}} \]
    3. associate--l+96.1%

      \[\leadsto {\left(\frac{N}{\color{blue}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - \frac{0.25}{{N}^{3}}\right)}}\right)}^{-1} \]
    4. div-inv96.1%

      \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - \color{blue}{0.25 \cdot \frac{1}{{N}^{3}}}\right)}\right)}^{-1} \]
    5. pow-flip96.1%

      \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot \color{blue}{{N}^{\left(-3\right)}}\right)}\right)}^{-1} \]
    6. metadata-eval96.1%

      \[\leadsto {\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{\color{blue}{-3}}\right)}\right)}^{-1} \]
  8. Applied egg-rr96.1%

    \[\leadsto \color{blue}{{\left(\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right)}\right)}^{-1}} \]
  9. Step-by-step derivation
    1. unpow-196.1%

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right)}}} \]
    2. +-commutative96.1%

      \[\leadsto \frac{1}{\frac{N}{\color{blue}{\left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} - 0.25 \cdot {N}^{-3}\right) + 1}}} \]
    3. sub-neg96.1%

      \[\leadsto \frac{1}{\frac{N}{\color{blue}{\left(\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} + \left(-0.25 \cdot {N}^{-3}\right)\right)} + 1}} \]
    4. associate-+l+96.1%

      \[\leadsto \frac{1}{\frac{N}{\color{blue}{\frac{-0.5 + \frac{0.3333333333333333}{N}}{N} + \left(\left(-0.25 \cdot {N}^{-3}\right) + 1\right)}}} \]
    5. +-commutative96.1%

      \[\leadsto \frac{1}{\frac{N}{\frac{\color{blue}{\frac{0.3333333333333333}{N} + -0.5}}{N} + \left(\left(-0.25 \cdot {N}^{-3}\right) + 1\right)}} \]
    6. distribute-lft-neg-in96.1%

      \[\leadsto \frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(\color{blue}{\left(-0.25\right) \cdot {N}^{-3}} + 1\right)}} \]
    7. metadata-eval96.1%

      \[\leadsto \frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(\color{blue}{-0.25} \cdot {N}^{-3} + 1\right)}} \]
  10. Simplified96.1%

    \[\leadsto \color{blue}{\frac{1}{\frac{N}{\frac{\frac{0.3333333333333333}{N} + -0.5}{N} + \left(-0.25 \cdot {N}^{-3} + 1\right)}}} \]
  11. Taylor expanded in N around inf 92.3%

    \[\leadsto \frac{1}{\color{blue}{N \cdot \left(1 + 0.5 \cdot \frac{1}{N}\right)}} \]
  12. Step-by-step derivation
    1. distribute-lft-in92.4%

      \[\leadsto \frac{1}{\color{blue}{N \cdot 1 + N \cdot \left(0.5 \cdot \frac{1}{N}\right)}} \]
    2. *-rgt-identity92.4%

      \[\leadsto \frac{1}{\color{blue}{N} + N \cdot \left(0.5 \cdot \frac{1}{N}\right)} \]
    3. associate-*r/92.4%

      \[\leadsto \frac{1}{N + N \cdot \color{blue}{\frac{0.5 \cdot 1}{N}}} \]
    4. metadata-eval92.4%

      \[\leadsto \frac{1}{N + N \cdot \frac{\color{blue}{0.5}}{N}} \]
    5. associate-*r/92.4%

      \[\leadsto \frac{1}{N + \color{blue}{\frac{N \cdot 0.5}{N}}} \]
    6. *-commutative92.4%

      \[\leadsto \frac{1}{N + \frac{\color{blue}{0.5 \cdot N}}{N}} \]
    7. associate-*r/92.4%

      \[\leadsto \frac{1}{N + \color{blue}{0.5 \cdot \frac{N}{N}}} \]
    8. *-inverses92.4%

      \[\leadsto \frac{1}{N + 0.5 \cdot \color{blue}{1}} \]
    9. metadata-eval92.4%

      \[\leadsto \frac{1}{N + \color{blue}{0.5}} \]
  13. Simplified92.4%

    \[\leadsto \frac{1}{\color{blue}{N + 0.5}} \]
  14. Taylor expanded in N around 0 9.9%

    \[\leadsto \color{blue}{2} \]
  15. Final simplification9.9%

    \[\leadsto 2 \]
  16. Add Preprocessing

Developer target: 99.8% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \mathsf{log1p}\left(\frac{1}{N}\right) \end{array} \]
(FPCore (N) :precision binary64 (log1p (/ 1.0 N)))
double code(double N) {
	return log1p((1.0 / N));
}
public static double code(double N) {
	return Math.log1p((1.0 / N));
}
def code(N):
	return math.log1p((1.0 / N))
function code(N)
	return log1p(Float64(1.0 / N))
end
code[N_] := N[Log[1 + N[(1.0 / N), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\mathsf{log1p}\left(\frac{1}{N}\right)
\end{array}

Reproduce

?
herbie shell --seed 2024095 
(FPCore (N)
  :name "2log (problem 3.3.6)"
  :precision binary64
  :pre (and (> N 1.0) (< N 1e+40))

  :alt
  (log1p (/ 1.0 N))

  (- (log (+ N 1.0)) (log N)))