2log (problem 3.3.6)

Percentage Accurate: 23.7% → 99.5%

Time: 9.8s

Alternatives: 10

Speedup: 17.3×

Specification

\[N > 1 \land N < 10^{+40}\]

Math

\[\begin{array}{l} \\ \log \left(N + 1\right) - \log N \end{array} \]

FPCore

(FPCore (N) :precision binary64 (- (log (+ N 1.0)) (log N)))

C

double code(double N) {
	return log((N + 1.0)) - log(N);
}

Fortran

real(8) function code(n)
    real(8), intent (in) :: n
    code = log((n + 1.0d0)) - log(n)
end function

Java

public static double code(double N) {
	return Math.log((N + 1.0)) - Math.log(N);
}

Python

def code(N):
	return math.log((N + 1.0)) - math.log(N)

Julia

function code(N)
	return Float64(log(Float64(N + 1.0)) - log(N))
end

MATLAB

function tmp = code(N)
	tmp = log((N + 1.0)) - log(N);
end

Wolfram

code[N_] := N[(N[Log[N[(N + 1.0), $MachinePrecision]], $MachinePrecision] - N[Log[N], $MachinePrecision]), $MachinePrecision]

Initial Program: 23.7% accurate, 1.0× speedup

Math

\[\begin{array}{l} \\ \log \left(N + 1\right) - \log N \end{array} \]

FPCore

(FPCore (N) :precision binary64 (- (log (+ N 1.0)) (log N)))

C

double code(double N) {
	return log((N + 1.0)) - log(N);
}

Fortran

real(8) function code(n)
    real(8), intent (in) :: n
    code = log((n + 1.0d0)) - log(n)
end function

Java

public static double code(double N) {
	return Math.log((N + 1.0)) - Math.log(N);
}

Python

def code(N):
	return math.log((N + 1.0)) - math.log(N)

Julia

function code(N)
	return Float64(log(Float64(N + 1.0)) - log(N))
end

MATLAB

function tmp = code(N)
	tmp = log((N + 1.0)) - log(N);
end

Wolfram

code[N_] := N[(N[Log[N[(N + 1.0), $MachinePrecision]], $MachinePrecision] - N[Log[N], $MachinePrecision]), $MachinePrecision]

Alternative 1: 99.5% accurate, 0.3× speedup

Math

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\log \left(N + 1\right) - \log N \leq 0.001:\\ \;\;\;\;\frac{1}{N + \left(0.5 - \frac{\mathsf{fma}\left(N, 0.08333333333333333, -0.041666666666666664\right)}{N \cdot N}\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{\log \left(\frac{N}{N + 1}\right) \cdot \left(\log \left(N + -1\right) - \log \left(N \cdot \mathsf{fma}\left(N, N, -1\right)\right)\right)}{\log \left(\mathsf{fma}\left(N, N, N\right)\right)}\\ \end{array} \end{array} \]

FPCore

(FPCore (N)
 :precision binary64
 (if (<= (- (log (+ N 1.0)) (log N)) 0.001)
   (/
    1.0
    (+
     N
     (- 0.5 (/ (fma N 0.08333333333333333 -0.041666666666666664) (* N N)))))
   (/
    (* (log (/ N (+ N 1.0))) (- (log (+ N -1.0)) (log (* N (fma N N -1.0)))))
    (log (fma N N N)))))

C

double code(double N) {
	double tmp;
	if ((log((N + 1.0)) - log(N)) <= 0.001) {
		tmp = 1.0 / (N + (0.5 - (fma(N, 0.08333333333333333, -0.041666666666666664) / (N * N))));
	} else {
		tmp = (log((N / (N + 1.0))) * (log((N + -1.0)) - log((N * fma(N, N, -1.0))))) / log(fma(N, N, N));
	}
	return tmp;
}

Julia

function code(N)
	tmp = 0.0
	if (Float64(log(Float64(N + 1.0)) - log(N)) <= 0.001)
		tmp = Float64(1.0 / Float64(N + Float64(0.5 - Float64(fma(N, 0.08333333333333333, -0.041666666666666664) / Float64(N * N)))));
	else
		tmp = Float64(Float64(log(Float64(N / Float64(N + 1.0))) * Float64(log(Float64(N + -1.0)) - log(Float64(N * fma(N, N, -1.0))))) / log(fma(N, N, N)));
	end
	return tmp
end

Wolfram

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[(0.5 - N[(N[(N * 0.08333333333333333 + -0.041666666666666664), $MachinePrecision] / N[(N * N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[Log[N[(N / N[(N + 1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[(N[Log[N[(N + -1.0), $MachinePrecision]], $MachinePrecision] - N[Log[N[(N * N[(N * N + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Log[N[(N * N + N), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]

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 18.0%

      \[\log \left(N + 1\right) - \log N \]
   2. Add Preprocessing

   3. Taylor expanded in N around inf

      \[\leadsto \color{blue}{\frac{\left(1 + \frac{\frac{1}{3}}{{N}^{2}}\right) - \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{4} \cdot \frac{1}{{N}^{3}}\right)}{N}} \]

   5. Simplified 99.8%

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

      1. clear-num N/A

         \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      2. /-lowering-/.f64 N/A

         \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      3. /-lowering-/.f64 N/A

         \[\leadsto \frac{1}{\color{blue}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      4. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{\color{blue}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      5. /-lowering-/.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \color{blue}{\frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      6. --lowering--.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{\color{blue}{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}}{N}}} \]

      7. /-lowering-/.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \color{blue}{\frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}}{N}}} \]

      8. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\color{blue}{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}}{N}}{N}}} \]

      9. /-lowering-/.f64 99.8

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{-0.5 - \frac{\color{blue}{\frac{0.25}{N}} + -0.3333333333333333}{N}}{N}}} \]

   7. Applied egg-rr 99.8%

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{-0.5 - \frac{\frac{0.25}{N} + -0.3333333333333333}{N}}{N}}}} \]

   8. Taylor expanded in N around inf

      \[\leadsto \frac{1}{\color{blue}{N \cdot \left(\left(1 + \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right)\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]
   9. Step-by-step derivation

      1. associate--l+ N/A

         \[\leadsto \frac{1}{N \cdot \color{blue}{\left(1 + \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

      2. distribute-lft-in N/A

         \[\leadsto \frac{1}{\color{blue}{N \cdot 1 + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

      3. *-rgt-identity N/A

         \[\leadsto \frac{1}{\color{blue}{N} + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)} \]

      4. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{\color{blue}{N + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

      5. *-lowering-*.f64 N/A

         \[\leadsto \frac{1}{N + \color{blue}{N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

      6. +-commutative N/A

         \[\leadsto \frac{1}{N + N \cdot \left(\color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \frac{1}{2} \cdot \frac{1}{N}\right)} - \frac{\frac{1}{12}}{{N}^{2}}\right)} \]

      7. associate--l+ N/A

         \[\leadsto \frac{1}{N + N \cdot \color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \left(\frac{1}{2} \cdot \frac{1}{N} - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

      8. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{N + N \cdot \color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \left(\frac{1}{2} \cdot \frac{1}{N} - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

   10. Simplified 99.9%

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

   11. Taylor expanded in N around inf

       \[\leadsto \frac{1}{N + \color{blue}{\left(\left(\frac{1}{2} + \frac{\frac{1}{24}}{{N}^{2}}\right) - \frac{1}{12} \cdot \frac{1}{N}\right)}} \]

   13. Simplified 99.9%

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

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

   1. Initial program 93.2%

      \[\log \left(N + 1\right) - \log N \]
   2. Add Preprocessing
   3. Step-by-step derivation

      1. flip-- N/A

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

      2. frac-2neg N/A

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

      3. /-lowering-/.f64 N/A

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

   4. Applied egg-rr 95.3%

      \[\leadsto \color{blue}{\frac{\log \left(\mathsf{fma}\left(N, N, N\right)\right) \cdot \log \left(\frac{N}{N + 1}\right)}{-\log \left(\mathsf{fma}\left(N, N, N\right)\right)}} \]
   5. Step-by-step derivation

      1. distribute-lft1-in N/A

         \[\leadsto \frac{\log \color{blue}{\left(\left(N + 1\right) \cdot N\right)} \cdot \log \left(\frac{N}{N + 1}\right)}{\mathsf{neg}\left(\log \left(\mathsf{fma}\left(N, N, N\right)\right)\right)} \]

      2. flip-+ N/A

         \[\leadsto \frac{\log \left(\color{blue}{\frac{N \cdot N - 1 \cdot 1}{N - 1}} \cdot N\right) \cdot \log \left(\frac{N}{N + 1}\right)}{\mathsf{neg}\left(\log \left(\mathsf{fma}\left(N, N, N\right)\right)\right)} \]

      3. metadata-eval N/A

         \[\leadsto \frac{\log \left(\frac{N \cdot N - \color{blue}{1}}{N - 1} \cdot N\right) \cdot \log \left(\frac{N}{N + 1}\right)}{\mathsf{neg}\left(\log \left(\mathsf{fma}\left(N, N, N\right)\right)\right)} \]

      4. sub-neg N/A

         \[\leadsto \frac{\log \left(\frac{\color{blue}{N \cdot N + \left(\mathsf{neg}\left(1\right)\right)}}{N - 1} \cdot N\right) \cdot \log \left(\frac{N}{N + 1}\right)}{\mathsf{neg}\left(\log \left(\mathsf{fma}\left(N, N, N\right)\right)\right)} \]

      5. metadata-eval N/A

         \[\leadsto \frac{\log \left(\frac{N \cdot N + \color{blue}{-1}}{N - 1} \cdot N\right) \cdot \log \left(\frac{N}{N + 1}\right)}{\mathsf{neg}\left(\log \left(\mathsf{fma}\left(N, N, N\right)\right)\right)} \]

      6. associate-*l/ N/A

         \[\leadsto \frac{\log \color{blue}{\left(\frac{\left(N \cdot N + -1\right) \cdot N}{N - 1}\right)} \cdot \log \left(\frac{N}{N + 1}\right)}{\mathsf{neg}\left(\log \left(\mathsf{fma}\left(N, N, N\right)\right)\right)} \]

      7. log-div N/A

         \[\leadsto \frac{\color{blue}{\left(\log \left(\left(N \cdot N + -1\right) \cdot N\right) - \log \left(N - 1\right)\right)} \cdot \log \left(\frac{N}{N + 1}\right)}{\mathsf{neg}\left(\log \left(\mathsf{fma}\left(N, N, N\right)\right)\right)} \]

      8. --lowering--.f64 N/A

         \[\leadsto \frac{\color{blue}{\left(\log \left(\left(N \cdot N + -1\right) \cdot N\right) - \log \left(N - 1\right)\right)} \cdot \log \left(\frac{N}{N + 1}\right)}{\mathsf{neg}\left(\log \left(\mathsf{fma}\left(N, N, N\right)\right)\right)} \]

      9. log-lowering-log.f64 N/A

         \[\leadsto \frac{\left(\color{blue}{\log \left(\left(N \cdot N + -1\right) \cdot N\right)} - \log \left(N - 1\right)\right) \cdot \log \left(\frac{N}{N + 1}\right)}{\mathsf{neg}\left(\log \left(\mathsf{fma}\left(N, N, N\right)\right)\right)} \]

      10. *-lowering-*.f64 N/A

          \[\leadsto \frac{\left(\log \color{blue}{\left(\left(N \cdot N + -1\right) \cdot N\right)} - \log \left(N - 1\right)\right) \cdot \log \left(\frac{N}{N + 1}\right)}{\mathsf{neg}\left(\log \left(\mathsf{fma}\left(N, N, N\right)\right)\right)} \]

      11. accelerator-lowering-fma.f64 N/A

          \[\leadsto \frac{\left(\log \left(\color{blue}{\mathsf{fma}\left(N, N, -1\right)} \cdot N\right) - \log \left(N - 1\right)\right) \cdot \log \left(\frac{N}{N + 1}\right)}{\mathsf{neg}\left(\log \left(\mathsf{fma}\left(N, N, N\right)\right)\right)} \]

      12. log-lowering-log.f64 N/A

          \[\leadsto \frac{\left(\log \left(\mathsf{fma}\left(N, N, -1\right) \cdot N\right) - \color{blue}{\log \left(N - 1\right)}\right) \cdot \log \left(\frac{N}{N + 1}\right)}{\mathsf{neg}\left(\log \left(\mathsf{fma}\left(N, N, N\right)\right)\right)} \]

      13. sub-neg N/A

          \[\leadsto \frac{\left(\log \left(\mathsf{fma}\left(N, N, -1\right) \cdot N\right) - \log \color{blue}{\left(N + \left(\mathsf{neg}\left(1\right)\right)\right)}\right) \cdot \log \left(\frac{N}{N + 1}\right)}{\mathsf{neg}\left(\log \left(\mathsf{fma}\left(N, N, N\right)\right)\right)} \]

      14. metadata-eval N/A

          \[\leadsto \frac{\left(\log \left(\mathsf{fma}\left(N, N, -1\right) \cdot N\right) - \log \left(N + \color{blue}{-1}\right)\right) \cdot \log \left(\frac{N}{N + 1}\right)}{\mathsf{neg}\left(\log \left(\mathsf{fma}\left(N, N, N\right)\right)\right)} \]

      15. +-lowering-+.f64 95.4

          \[\leadsto \frac{\left(\log \left(\mathsf{fma}\left(N, N, -1\right) \cdot N\right) - \log \color{blue}{\left(N + -1\right)}\right) \cdot \log \left(\frac{N}{N + 1}\right)}{-\log \left(\mathsf{fma}\left(N, N, N\right)\right)} \]

   6. Applied egg-rr 95.4%

      \[\leadsto \frac{\color{blue}{\left(\log \left(\mathsf{fma}\left(N, N, -1\right) \cdot N\right) - \log \left(N + -1\right)\right)} \cdot \log \left(\frac{N}{N + 1}\right)}{-\log \left(\mathsf{fma}\left(N, N, N\right)\right)} \]
3. Recombined 2 regimes into one program.

4. Final simplification 99.6%

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

Alternative 2: 99.5% accurate, 0.6× speedup

Math

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \log \left(\mathsf{fma}\left(N, N, N\right)\right)\\ \mathbf{if}\;N \leq 950:\\ \;\;\;\;\frac{-1}{\frac{t\_0}{\log \left(\frac{N}{N + 1}\right) \cdot t\_0}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{N + \left(0.5 - \frac{\mathsf{fma}\left(N, 0.08333333333333333, -0.041666666666666664\right)}{N \cdot N}\right)}\\ \end{array} \end{array} \]

FPCore

(FPCore (N)
 :precision binary64
 (let* ((t_0 (log (fma N N N))))
   (if (<= N 950.0)
     (/ -1.0 (/ t_0 (* (log (/ N (+ N 1.0))) t_0)))
     (/
      1.0
      (+
       N
       (-
        0.5
        (/ (fma N 0.08333333333333333 -0.041666666666666664) (* N N))))))))

C

double code(double N) {
	double t_0 = log(fma(N, N, N));
	double tmp;
	if (N <= 950.0) {
		tmp = -1.0 / (t_0 / (log((N / (N + 1.0))) * t_0));
	} else {
		tmp = 1.0 / (N + (0.5 - (fma(N, 0.08333333333333333, -0.041666666666666664) / (N * N))));
	}
	return tmp;
}

Julia

function code(N)
	t_0 = log(fma(N, N, N))
	tmp = 0.0
	if (N <= 950.0)
		tmp = Float64(-1.0 / Float64(t_0 / Float64(log(Float64(N / Float64(N + 1.0))) * t_0)));
	else
		tmp = Float64(1.0 / Float64(N + Float64(0.5 - Float64(fma(N, 0.08333333333333333, -0.041666666666666664) / Float64(N * N)))));
	end
	return tmp
end

Wolfram

code[N_] := Block[{t$95$0 = N[Log[N[(N * N + N), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[N, 950.0], N[(-1.0 / N[(t$95$0 / N[(N[Log[N[(N / N[(N + 1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N + N[(0.5 - N[(N[(N * 0.08333333333333333 + -0.041666666666666664), $MachinePrecision] / N[(N * N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]

Derivation

1. Split input into 2 regimes

2. if N < 950

   1. Initial program 93.2%

      \[\log \left(N + 1\right) - \log N \]
   2. Add Preprocessing
   3. Step-by-step derivation

      1. diff-log N/A

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

      2. flip-+ N/A

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

      3. associate-/l/ N/A

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

      4. clear-num N/A

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

      5. log-rec N/A

         \[\leadsto \color{blue}{\mathsf{neg}\left(\log \left(\frac{N \cdot \left(N - 1\right)}{N \cdot N - 1 \cdot 1}\right)\right)} \]

      6. neg-lowering-neg.f64 N/A

         \[\leadsto \color{blue}{\mathsf{neg}\left(\log \left(\frac{N \cdot \left(N - 1\right)}{N \cdot N - 1 \cdot 1}\right)\right)} \]

      7. log-lowering-log.f64 N/A

         \[\leadsto \mathsf{neg}\left(\color{blue}{\log \left(\frac{N \cdot \left(N - 1\right)}{N \cdot N - 1 \cdot 1}\right)}\right) \]

      8. distribute-rgt-out-- N/A

         \[\leadsto \mathsf{neg}\left(\log \left(\frac{\color{blue}{N \cdot N - 1 \cdot N}}{N \cdot N - 1 \cdot 1}\right)\right) \]

      9. /-lowering-/.f64 N/A

         \[\leadsto \mathsf{neg}\left(\log \color{blue}{\left(\frac{N \cdot N - 1 \cdot N}{N \cdot N - 1 \cdot 1}\right)}\right) \]

      10. *-lft-identity N/A

          \[\leadsto \mathsf{neg}\left(\log \left(\frac{N \cdot N - \color{blue}{N}}{N \cdot N - 1 \cdot 1}\right)\right) \]

      11. --lowering--.f64 N/A

          \[\leadsto \mathsf{neg}\left(\log \left(\frac{\color{blue}{N \cdot N - N}}{N \cdot N - 1 \cdot 1}\right)\right) \]

      12. *-lowering-*.f64 N/A

          \[\leadsto \mathsf{neg}\left(\log \left(\frac{\color{blue}{N \cdot N} - N}{N \cdot N - 1 \cdot 1}\right)\right) \]

      13. metadata-eval N/A

          \[\leadsto \mathsf{neg}\left(\log \left(\frac{N \cdot N - N}{N \cdot N - \color{blue}{1}}\right)\right) \]

      14. sub-neg N/A

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

      15. accelerator-lowering-fma.f64 N/A

          \[\leadsto \mathsf{neg}\left(\log \left(\frac{N \cdot N - N}{\color{blue}{\mathsf{fma}\left(N, N, \mathsf{neg}\left(1\right)\right)}}\right)\right) \]

      16. metadata-eval 94.5

          \[\leadsto -\log \left(\frac{N \cdot N - N}{\mathsf{fma}\left(N, N, \color{blue}{-1}\right)}\right) \]

   4. Applied egg-rr 94.5%

      \[\leadsto \color{blue}{-\log \left(\frac{N \cdot N - N}{\mathsf{fma}\left(N, N, -1\right)}\right)} \]
   5. Step-by-step derivation

      1. clear-num N/A

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

      2. clear-num N/A

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

      3. *-lft-identity N/A

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

      4. distribute-rgt-out-- N/A

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

      5. associate-/l/ N/A

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

      6. metadata-eval N/A

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

      7. sub-neg N/A

         \[\leadsto \mathsf{neg}\left(\log \left(\frac{1}{\frac{\frac{\frac{\color{blue}{N \cdot N - 1}}{N - 1}}{N}}{1}}\right)\right) \]

      8. metadata-eval N/A

         \[\leadsto \mathsf{neg}\left(\log \left(\frac{1}{\frac{\frac{\frac{N \cdot N - \color{blue}{1 \cdot 1}}{N - 1}}{N}}{1}}\right)\right) \]

      9. flip-+ N/A

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

      10. clear-num N/A

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

      11. clear-num N/A

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

      12. log-div N/A

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

      13. +-commutative N/A

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

      14. sub-neg N/A

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

   6. Applied egg-rr 92.1%

      \[\leadsto -\color{blue}{\mathsf{fma}\left(\sqrt{\log N}, \sqrt{\log N}, -\mathsf{log1p}\left(N\right)\right)} \]

   8. Applied egg-rr 95.3%

      \[\leadsto -\color{blue}{\frac{1}{\frac{\log \left(\mathsf{fma}\left(N, N, N\right)\right)}{\log \left(\frac{N}{N + 1}\right) \cdot \log \left(\mathsf{fma}\left(N, N, N\right)\right)}}} \]

   if 950 < N

   1. Initial program 18.0%

      \[\log \left(N + 1\right) - \log N \]
   2. Add Preprocessing

   3. Taylor expanded in N around inf

      \[\leadsto \color{blue}{\frac{\left(1 + \frac{\frac{1}{3}}{{N}^{2}}\right) - \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{4} \cdot \frac{1}{{N}^{3}}\right)}{N}} \]

   5. Simplified 99.8%

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

      1. clear-num N/A

         \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      2. /-lowering-/.f64 N/A

         \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      3. /-lowering-/.f64 N/A

         \[\leadsto \frac{1}{\color{blue}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      4. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{\color{blue}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      5. /-lowering-/.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \color{blue}{\frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      6. --lowering--.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{\color{blue}{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}}{N}}} \]

      7. /-lowering-/.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \color{blue}{\frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}}{N}}} \]

      8. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\color{blue}{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}}{N}}{N}}} \]

      9. /-lowering-/.f64 99.8

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{-0.5 - \frac{\color{blue}{\frac{0.25}{N}} + -0.3333333333333333}{N}}{N}}} \]

   7. Applied egg-rr 99.8%

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{-0.5 - \frac{\frac{0.25}{N} + -0.3333333333333333}{N}}{N}}}} \]

   8. Taylor expanded in N around inf

      \[\leadsto \frac{1}{\color{blue}{N \cdot \left(\left(1 + \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right)\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]
   9. Step-by-step derivation

      1. associate--l+ N/A

         \[\leadsto \frac{1}{N \cdot \color{blue}{\left(1 + \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

      2. distribute-lft-in N/A

         \[\leadsto \frac{1}{\color{blue}{N \cdot 1 + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

      3. *-rgt-identity N/A

         \[\leadsto \frac{1}{\color{blue}{N} + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)} \]

      4. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{\color{blue}{N + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

      5. *-lowering-*.f64 N/A

         \[\leadsto \frac{1}{N + \color{blue}{N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

      6. +-commutative N/A

         \[\leadsto \frac{1}{N + N \cdot \left(\color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \frac{1}{2} \cdot \frac{1}{N}\right)} - \frac{\frac{1}{12}}{{N}^{2}}\right)} \]

      7. associate--l+ N/A

         \[\leadsto \frac{1}{N + N \cdot \color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \left(\frac{1}{2} \cdot \frac{1}{N} - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

      8. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{N + N \cdot \color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \left(\frac{1}{2} \cdot \frac{1}{N} - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

   10. Simplified 99.9%

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

   11. Taylor expanded in N around inf

       \[\leadsto \frac{1}{N + \color{blue}{\left(\left(\frac{1}{2} + \frac{\frac{1}{24}}{{N}^{2}}\right) - \frac{1}{12} \cdot \frac{1}{N}\right)}} \]

   13. Simplified 99.9%

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

4. Final simplification 99.6%

   \[\leadsto \begin{array}{l} \mathbf{if}\;N \leq 950:\\ \;\;\;\;\frac{-1}{\frac{\log \left(\mathsf{fma}\left(N, N, N\right)\right)}{\log \left(\frac{N}{N + 1}\right) \cdot \log \left(\mathsf{fma}\left(N, N, N\right)\right)}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{N + \left(0.5 - \frac{\mathsf{fma}\left(N, 0.08333333333333333, -0.041666666666666664\right)}{N \cdot N}\right)}\\ \end{array} \]
5. Add Preprocessing

Alternative 3: 99.5% accurate, 0.6× speedup

Math

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \log \left(\mathsf{fma}\left(N, N, N\right)\right)\\ \mathbf{if}\;N \leq 950:\\ \;\;\;\;\frac{\log \left(\frac{N}{N + 1}\right) \cdot t\_0}{-t\_0}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{N + \left(0.5 - \frac{\mathsf{fma}\left(N, 0.08333333333333333, -0.041666666666666664\right)}{N \cdot N}\right)}\\ \end{array} \end{array} \]

FPCore

(FPCore (N)
 :precision binary64
 (let* ((t_0 (log (fma N N N))))
   (if (<= N 950.0)
     (/ (* (log (/ N (+ N 1.0))) t_0) (- t_0))
     (/
      1.0
      (+
       N
       (-
        0.5
        (/ (fma N 0.08333333333333333 -0.041666666666666664) (* N N))))))))

C

double code(double N) {
	double t_0 = log(fma(N, N, N));
	double tmp;
	if (N <= 950.0) {
		tmp = (log((N / (N + 1.0))) * t_0) / -t_0;
	} else {
		tmp = 1.0 / (N + (0.5 - (fma(N, 0.08333333333333333, -0.041666666666666664) / (N * N))));
	}
	return tmp;
}

Julia

function code(N)
	t_0 = log(fma(N, N, N))
	tmp = 0.0
	if (N <= 950.0)
		tmp = Float64(Float64(log(Float64(N / Float64(N + 1.0))) * t_0) / Float64(-t_0));
	else
		tmp = Float64(1.0 / Float64(N + Float64(0.5 - Float64(fma(N, 0.08333333333333333, -0.041666666666666664) / Float64(N * N)))));
	end
	return tmp
end

Wolfram

code[N_] := Block[{t$95$0 = N[Log[N[(N * N + N), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[N, 950.0], N[(N[(N[Log[N[(N / N[(N + 1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * t$95$0), $MachinePrecision] / (-t$95$0)), $MachinePrecision], N[(1.0 / N[(N + N[(0.5 - N[(N[(N * 0.08333333333333333 + -0.041666666666666664), $MachinePrecision] / N[(N * N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]

Derivation

1. Split input into 2 regimes

2. if N < 950

   1. Initial program 93.2%

      \[\log \left(N + 1\right) - \log N \]
   2. Add Preprocessing
   3. Step-by-step derivation

      1. flip-- N/A

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

      2. frac-2neg N/A

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

      3. /-lowering-/.f64 N/A

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

   4. Applied egg-rr 95.3%

      \[\leadsto \color{blue}{\frac{\log \left(\mathsf{fma}\left(N, N, N\right)\right) \cdot \log \left(\frac{N}{N + 1}\right)}{-\log \left(\mathsf{fma}\left(N, N, N\right)\right)}} \]

   if 950 < N

   1. Initial program 18.0%

      \[\log \left(N + 1\right) - \log N \]
   2. Add Preprocessing

   3. Taylor expanded in N around inf

      \[\leadsto \color{blue}{\frac{\left(1 + \frac{\frac{1}{3}}{{N}^{2}}\right) - \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{4} \cdot \frac{1}{{N}^{3}}\right)}{N}} \]

   5. Simplified 99.8%

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

      1. clear-num N/A

         \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      2. /-lowering-/.f64 N/A

         \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      3. /-lowering-/.f64 N/A

         \[\leadsto \frac{1}{\color{blue}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      4. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{\color{blue}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      5. /-lowering-/.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \color{blue}{\frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      6. --lowering--.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{\color{blue}{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}}{N}}} \]

      7. /-lowering-/.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \color{blue}{\frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}}{N}}} \]

      8. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\color{blue}{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}}{N}}{N}}} \]

      9. /-lowering-/.f64 99.8

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{-0.5 - \frac{\color{blue}{\frac{0.25}{N}} + -0.3333333333333333}{N}}{N}}} \]

   7. Applied egg-rr 99.8%

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{-0.5 - \frac{\frac{0.25}{N} + -0.3333333333333333}{N}}{N}}}} \]

   8. Taylor expanded in N around inf

      \[\leadsto \frac{1}{\color{blue}{N \cdot \left(\left(1 + \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right)\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]
   9. Step-by-step derivation

      1. associate--l+ N/A

         \[\leadsto \frac{1}{N \cdot \color{blue}{\left(1 + \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

      2. distribute-lft-in N/A

         \[\leadsto \frac{1}{\color{blue}{N \cdot 1 + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

      3. *-rgt-identity N/A

         \[\leadsto \frac{1}{\color{blue}{N} + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)} \]

      4. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{\color{blue}{N + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

      5. *-lowering-*.f64 N/A

         \[\leadsto \frac{1}{N + \color{blue}{N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

      6. +-commutative N/A

         \[\leadsto \frac{1}{N + N \cdot \left(\color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \frac{1}{2} \cdot \frac{1}{N}\right)} - \frac{\frac{1}{12}}{{N}^{2}}\right)} \]

      7. associate--l+ N/A

         \[\leadsto \frac{1}{N + N \cdot \color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \left(\frac{1}{2} \cdot \frac{1}{N} - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

      8. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{N + N \cdot \color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \left(\frac{1}{2} \cdot \frac{1}{N} - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

   10. Simplified 99.9%

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

   11. Taylor expanded in N around inf

       \[\leadsto \frac{1}{N + \color{blue}{\left(\left(\frac{1}{2} + \frac{\frac{1}{24}}{{N}^{2}}\right) - \frac{1}{12} \cdot \frac{1}{N}\right)}} \]

   13. Simplified 99.9%

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

4. Final simplification 99.6%

   \[\leadsto \begin{array}{l} \mathbf{if}\;N \leq 950:\\ \;\;\;\;\frac{\log \left(\frac{N}{N + 1}\right) \cdot \log \left(\mathsf{fma}\left(N, N, N\right)\right)}{-\log \left(\mathsf{fma}\left(N, N, N\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{N + \left(0.5 - \frac{\mathsf{fma}\left(N, 0.08333333333333333, -0.041666666666666664\right)}{N \cdot N}\right)}\\ \end{array} \]
5. Add Preprocessing

Alternative 4: 99.5% accurate, 0.6× speedup

Math

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\log \left(N + 1\right) - \log N \leq 0.001:\\ \;\;\;\;\frac{1}{N + \left(0.5 - \frac{\mathsf{fma}\left(N, 0.08333333333333333, -0.041666666666666664\right)}{N \cdot N}\right)}\\ \mathbf{else}:\\ \;\;\;\;-\log \left(\frac{N}{N + 1}\right)\\ \end{array} \end{array} \]

FPCore

(FPCore (N)
 :precision binary64
 (if (<= (- (log (+ N 1.0)) (log N)) 0.001)
   (/
    1.0
    (+
     N
     (- 0.5 (/ (fma N 0.08333333333333333 -0.041666666666666664) (* N N)))))
   (- (log (/ N (+ N 1.0))))))

C

double code(double N) {
	double tmp;
	if ((log((N + 1.0)) - log(N)) <= 0.001) {
		tmp = 1.0 / (N + (0.5 - (fma(N, 0.08333333333333333, -0.041666666666666664) / (N * N))));
	} else {
		tmp = -log((N / (N + 1.0)));
	}
	return tmp;
}

Julia

function code(N)
	tmp = 0.0
	if (Float64(log(Float64(N + 1.0)) - log(N)) <= 0.001)
		tmp = Float64(1.0 / Float64(N + Float64(0.5 - Float64(fma(N, 0.08333333333333333, -0.041666666666666664) / Float64(N * N)))));
	else
		tmp = Float64(-log(Float64(N / Float64(N + 1.0))));
	end
	return tmp
end

Wolfram

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[(0.5 - N[(N[(N * 0.08333333333333333 + -0.041666666666666664), $MachinePrecision] / N[(N * N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], (-N[Log[N[(N / N[(N + 1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision])]

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 18.0%

      \[\log \left(N + 1\right) - \log N \]
   2. Add Preprocessing

   3. Taylor expanded in N around inf

      \[\leadsto \color{blue}{\frac{\left(1 + \frac{\frac{1}{3}}{{N}^{2}}\right) - \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{4} \cdot \frac{1}{{N}^{3}}\right)}{N}} \]

   5. Simplified 99.8%

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

      1. clear-num N/A

         \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      2. /-lowering-/.f64 N/A

         \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      3. /-lowering-/.f64 N/A

         \[\leadsto \frac{1}{\color{blue}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      4. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{\color{blue}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      5. /-lowering-/.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \color{blue}{\frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      6. --lowering--.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{\color{blue}{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}}{N}}} \]

      7. /-lowering-/.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \color{blue}{\frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}}{N}}} \]

      8. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\color{blue}{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}}{N}}{N}}} \]

      9. /-lowering-/.f64 99.8

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{-0.5 - \frac{\color{blue}{\frac{0.25}{N}} + -0.3333333333333333}{N}}{N}}} \]

   7. Applied egg-rr 99.8%

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{-0.5 - \frac{\frac{0.25}{N} + -0.3333333333333333}{N}}{N}}}} \]

   8. Taylor expanded in N around inf

      \[\leadsto \frac{1}{\color{blue}{N \cdot \left(\left(1 + \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right)\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]
   9. Step-by-step derivation

      1. associate--l+ N/A

         \[\leadsto \frac{1}{N \cdot \color{blue}{\left(1 + \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

      2. distribute-lft-in N/A

         \[\leadsto \frac{1}{\color{blue}{N \cdot 1 + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

      3. *-rgt-identity N/A

         \[\leadsto \frac{1}{\color{blue}{N} + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)} \]

      4. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{\color{blue}{N + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

      5. *-lowering-*.f64 N/A

         \[\leadsto \frac{1}{N + \color{blue}{N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

      6. +-commutative N/A

         \[\leadsto \frac{1}{N + N \cdot \left(\color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \frac{1}{2} \cdot \frac{1}{N}\right)} - \frac{\frac{1}{12}}{{N}^{2}}\right)} \]

      7. associate--l+ N/A

         \[\leadsto \frac{1}{N + N \cdot \color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \left(\frac{1}{2} \cdot \frac{1}{N} - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

      8. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{N + N \cdot \color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \left(\frac{1}{2} \cdot \frac{1}{N} - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

   10. Simplified 99.9%

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

   11. Taylor expanded in N around inf

       \[\leadsto \frac{1}{N + \color{blue}{\left(\left(\frac{1}{2} + \frac{\frac{1}{24}}{{N}^{2}}\right) - \frac{1}{12} \cdot \frac{1}{N}\right)}} \]

   13. Simplified 99.9%

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

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

   1. Initial program 93.2%

      \[\log \left(N + 1\right) - \log N \]
   2. Add Preprocessing
   3. Step-by-step derivation

      1. diff-log N/A

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

      2. clear-num N/A

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

      3. neg-log N/A

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

      4. diff-log N/A

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

      5. neg-lowering-neg.f64 N/A

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

      6. diff-log N/A

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

      7. log-lowering-log.f64 N/A

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

      8. /-lowering-/.f64 N/A

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

      9. +-lowering-+.f64 95.2

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

   4. Applied egg-rr 95.2%

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

Alternative 5: 99.5% accurate, 0.6× speedup

Math

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\log \left(N + 1\right) - \log N \leq 0.001:\\ \;\;\;\;\frac{1}{N + \left(0.5 - \frac{\mathsf{fma}\left(N, 0.08333333333333333, -0.041666666666666664\right)}{N \cdot N}\right)}\\ \mathbf{else}:\\ \;\;\;\;\log \left(\frac{N + 1}{N}\right)\\ \end{array} \end{array} \]

FPCore

(FPCore (N)
 :precision binary64
 (if (<= (- (log (+ N 1.0)) (log N)) 0.001)
   (/
    1.0
    (+
     N
     (- 0.5 (/ (fma N 0.08333333333333333 -0.041666666666666664) (* N N)))))
   (log (/ (+ N 1.0) N))))

C

double code(double N) {
	double tmp;
	if ((log((N + 1.0)) - log(N)) <= 0.001) {
		tmp = 1.0 / (N + (0.5 - (fma(N, 0.08333333333333333, -0.041666666666666664) / (N * N))));
	} else {
		tmp = log(((N + 1.0) / N));
	}
	return tmp;
}

Julia

function code(N)
	tmp = 0.0
	if (Float64(log(Float64(N + 1.0)) - log(N)) <= 0.001)
		tmp = Float64(1.0 / Float64(N + Float64(0.5 - Float64(fma(N, 0.08333333333333333, -0.041666666666666664) / Float64(N * N)))));
	else
		tmp = log(Float64(Float64(N + 1.0) / N));
	end
	return tmp
end

Wolfram

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[(0.5 - N[(N[(N * 0.08333333333333333 + -0.041666666666666664), $MachinePrecision] / N[(N * N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[Log[N[(N[(N + 1.0), $MachinePrecision] / N), $MachinePrecision]], $MachinePrecision]]

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 18.0%

      \[\log \left(N + 1\right) - \log N \]
   2. Add Preprocessing

   3. Taylor expanded in N around inf

      \[\leadsto \color{blue}{\frac{\left(1 + \frac{\frac{1}{3}}{{N}^{2}}\right) - \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{4} \cdot \frac{1}{{N}^{3}}\right)}{N}} \]

   5. Simplified 99.8%

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

      1. clear-num N/A

         \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      2. /-lowering-/.f64 N/A

         \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      3. /-lowering-/.f64 N/A

         \[\leadsto \frac{1}{\color{blue}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      4. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{\color{blue}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      5. /-lowering-/.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \color{blue}{\frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

      6. --lowering--.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{\color{blue}{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}}{N}}} \]

      7. /-lowering-/.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \color{blue}{\frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}}{N}}} \]

      8. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\color{blue}{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}}{N}}{N}}} \]

      9. /-lowering-/.f64 99.8

         \[\leadsto \frac{1}{\frac{N}{1 + \frac{-0.5 - \frac{\color{blue}{\frac{0.25}{N}} + -0.3333333333333333}{N}}{N}}} \]

   7. Applied egg-rr 99.8%

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{-0.5 - \frac{\frac{0.25}{N} + -0.3333333333333333}{N}}{N}}}} \]

   8. Taylor expanded in N around inf

      \[\leadsto \frac{1}{\color{blue}{N \cdot \left(\left(1 + \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right)\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]
   9. Step-by-step derivation

      1. associate--l+ N/A

         \[\leadsto \frac{1}{N \cdot \color{blue}{\left(1 + \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

      2. distribute-lft-in N/A

         \[\leadsto \frac{1}{\color{blue}{N \cdot 1 + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

      3. *-rgt-identity N/A

         \[\leadsto \frac{1}{\color{blue}{N} + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)} \]

      4. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{\color{blue}{N + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

      5. *-lowering-*.f64 N/A

         \[\leadsto \frac{1}{N + \color{blue}{N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

      6. +-commutative N/A

         \[\leadsto \frac{1}{N + N \cdot \left(\color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \frac{1}{2} \cdot \frac{1}{N}\right)} - \frac{\frac{1}{12}}{{N}^{2}}\right)} \]

      7. associate--l+ N/A

         \[\leadsto \frac{1}{N + N \cdot \color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \left(\frac{1}{2} \cdot \frac{1}{N} - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

      8. +-lowering-+.f64 N/A

         \[\leadsto \frac{1}{N + N \cdot \color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \left(\frac{1}{2} \cdot \frac{1}{N} - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

   10. Simplified 99.9%

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

   11. Taylor expanded in N around inf

       \[\leadsto \frac{1}{N + \color{blue}{\left(\left(\frac{1}{2} + \frac{\frac{1}{24}}{{N}^{2}}\right) - \frac{1}{12} \cdot \frac{1}{N}\right)}} \]

   13. Simplified 99.9%

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

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

   1. Initial program 93.2%

      \[\log \left(N + 1\right) - \log N \]
   2. Add Preprocessing
   3. Step-by-step derivation

      1. diff-log N/A

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

      2. log-lowering-log.f64 N/A

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

      3. /-lowering-/.f64 N/A

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

      4. +-lowering-+.f64 93.8

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

   4. Applied egg-rr 93.8%

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

Alternative 6: 96.7% accurate, 5.2× speedup

Math

\[\begin{array}{l} \\ \frac{1}{N + \left(0.5 - \frac{\mathsf{fma}\left(N, 0.08333333333333333, -0.041666666666666664\right)}{N \cdot N}\right)} \end{array} \]

FPCore

(FPCore (N)
 :precision binary64
 (/
  1.0
  (+ N (- 0.5 (/ (fma N 0.08333333333333333 -0.041666666666666664) (* N N))))))

C

double code(double N) {
	return 1.0 / (N + (0.5 - (fma(N, 0.08333333333333333, -0.041666666666666664) / (N * N))));
}

Julia

function code(N)
	return Float64(1.0 / Float64(N + Float64(0.5 - Float64(fma(N, 0.08333333333333333, -0.041666666666666664) / Float64(N * N)))))
end

Wolfram

code[N_] := N[(1.0 / N[(N + N[(0.5 - N[(N[(N * 0.08333333333333333 + -0.041666666666666664), $MachinePrecision] / N[(N * N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]

Derivation

1. Initial program 22.7%

   \[\log \left(N + 1\right) - \log N \]
2. Add Preprocessing

3. Taylor expanded in N around inf

   \[\leadsto \color{blue}{\frac{\left(1 + \frac{\frac{1}{3}}{{N}^{2}}\right) - \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{4} \cdot \frac{1}{{N}^{3}}\right)}{N}} \]

5. Simplified 96.7%

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

   1. clear-num N/A

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   2. /-lowering-/.f64 N/A

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   3. /-lowering-/.f64 N/A

      \[\leadsto \frac{1}{\color{blue}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   4. +-lowering-+.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{\color{blue}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   5. /-lowering-/.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{1 + \color{blue}{\frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   6. --lowering--.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{1 + \frac{\color{blue}{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}}{N}}} \]

   7. /-lowering-/.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \color{blue}{\frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}}{N}}} \]

   8. +-lowering-+.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\color{blue}{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}}{N}}{N}}} \]

   9. /-lowering-/.f64 96.8

      \[\leadsto \frac{1}{\frac{N}{1 + \frac{-0.5 - \frac{\color{blue}{\frac{0.25}{N}} + -0.3333333333333333}{N}}{N}}} \]

7. Applied egg-rr 96.8%

   \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{-0.5 - \frac{\frac{0.25}{N} + -0.3333333333333333}{N}}{N}}}} \]

8. Taylor expanded in N around inf

   \[\leadsto \frac{1}{\color{blue}{N \cdot \left(\left(1 + \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right)\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]
9. Step-by-step derivation

   1. associate--l+ N/A

      \[\leadsto \frac{1}{N \cdot \color{blue}{\left(1 + \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

   2. distribute-lft-in N/A

      \[\leadsto \frac{1}{\color{blue}{N \cdot 1 + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

   3. *-rgt-identity N/A

      \[\leadsto \frac{1}{\color{blue}{N} + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)} \]

   4. +-lowering-+.f64 N/A

      \[\leadsto \frac{1}{\color{blue}{N + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

   5. *-lowering-*.f64 N/A

      \[\leadsto \frac{1}{N + \color{blue}{N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

   6. +-commutative N/A

      \[\leadsto \frac{1}{N + N \cdot \left(\color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \frac{1}{2} \cdot \frac{1}{N}\right)} - \frac{\frac{1}{12}}{{N}^{2}}\right)} \]

   7. associate--l+ N/A

      \[\leadsto \frac{1}{N + N \cdot \color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \left(\frac{1}{2} \cdot \frac{1}{N} - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

   8. +-lowering-+.f64 N/A

      \[\leadsto \frac{1}{N + N \cdot \color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \left(\frac{1}{2} \cdot \frac{1}{N} - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

10. Simplified 97.1%

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

11. Taylor expanded in N around inf

    \[\leadsto \frac{1}{N + \color{blue}{\left(\left(\frac{1}{2} + \frac{\frac{1}{24}}{{N}^{2}}\right) - \frac{1}{12} \cdot \frac{1}{N}\right)}} \]

13. Simplified 97.1%

    \[\leadsto \frac{1}{N + \color{blue}{\left(0.5 - \frac{\mathsf{fma}\left(N, 0.08333333333333333, -0.041666666666666664\right)}{N \cdot N}\right)}} \]
14. Add Preprocessing

Alternative 7: 95.5% accurate, 7.1× speedup

Math

\[\begin{array}{l} \\ \frac{1}{N + \left(0.5 + \frac{-0.08333333333333333}{N}\right)} \end{array} \]

FPCore

(FPCore (N)
 :precision binary64
 (/ 1.0 (+ N (+ 0.5 (/ -0.08333333333333333 N)))))

C

double code(double N) {
	return 1.0 / (N + (0.5 + (-0.08333333333333333 / N)));
}

Fortran

real(8) function code(n)
    real(8), intent (in) :: n
    code = 1.0d0 / (n + (0.5d0 + ((-0.08333333333333333d0) / n)))
end function

Java

public static double code(double N) {
	return 1.0 / (N + (0.5 + (-0.08333333333333333 / N)));
}

Python

def code(N):
	return 1.0 / (N + (0.5 + (-0.08333333333333333 / N)))

Julia

function code(N)
	return Float64(1.0 / Float64(N + Float64(0.5 + Float64(-0.08333333333333333 / N))))
end

MATLAB

function tmp = code(N)
	tmp = 1.0 / (N + (0.5 + (-0.08333333333333333 / N)));
end

Wolfram

code[N_] := N[(1.0 / N[(N + N[(0.5 + N[(-0.08333333333333333 / N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]

Derivation

1. Initial program 22.7%

   \[\log \left(N + 1\right) - \log N \]
2. Add Preprocessing

3. Taylor expanded in N around inf

   \[\leadsto \color{blue}{\frac{\left(1 + \frac{\frac{1}{3}}{{N}^{2}}\right) - \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{4} \cdot \frac{1}{{N}^{3}}\right)}{N}} \]

5. Simplified 96.7%

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

   1. clear-num N/A

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   2. /-lowering-/.f64 N/A

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   3. /-lowering-/.f64 N/A

      \[\leadsto \frac{1}{\color{blue}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   4. +-lowering-+.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{\color{blue}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   5. /-lowering-/.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{1 + \color{blue}{\frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   6. --lowering--.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{1 + \frac{\color{blue}{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}}{N}}} \]

   7. /-lowering-/.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \color{blue}{\frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}}{N}}} \]

   8. +-lowering-+.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\color{blue}{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}}{N}}{N}}} \]

   9. /-lowering-/.f64 96.8

      \[\leadsto \frac{1}{\frac{N}{1 + \frac{-0.5 - \frac{\color{blue}{\frac{0.25}{N}} + -0.3333333333333333}{N}}{N}}} \]

7. Applied egg-rr 96.8%

   \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{-0.5 - \frac{\frac{0.25}{N} + -0.3333333333333333}{N}}{N}}}} \]

8. Taylor expanded in N around inf

   \[\leadsto \frac{1}{\color{blue}{N \cdot \left(\left(1 + \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right)\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]
9. Step-by-step derivation

   1. associate--l+ N/A

      \[\leadsto \frac{1}{N \cdot \color{blue}{\left(1 + \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

   2. distribute-lft-in N/A

      \[\leadsto \frac{1}{\color{blue}{N \cdot 1 + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

   3. *-rgt-identity N/A

      \[\leadsto \frac{1}{\color{blue}{N} + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)} \]

   4. +-lowering-+.f64 N/A

      \[\leadsto \frac{1}{\color{blue}{N + N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

   5. *-lowering-*.f64 N/A

      \[\leadsto \frac{1}{N + \color{blue}{N \cdot \left(\left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{24} \cdot \frac{1}{{N}^{3}}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]

   6. +-commutative N/A

      \[\leadsto \frac{1}{N + N \cdot \left(\color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \frac{1}{2} \cdot \frac{1}{N}\right)} - \frac{\frac{1}{12}}{{N}^{2}}\right)} \]

   7. associate--l+ N/A

      \[\leadsto \frac{1}{N + N \cdot \color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \left(\frac{1}{2} \cdot \frac{1}{N} - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

   8. +-lowering-+.f64 N/A

      \[\leadsto \frac{1}{N + N \cdot \color{blue}{\left(\frac{1}{24} \cdot \frac{1}{{N}^{3}} + \left(\frac{1}{2} \cdot \frac{1}{N} - \frac{\frac{1}{12}}{{N}^{2}}\right)\right)}} \]

10. Simplified 97.1%

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

11. Taylor expanded in N around inf

    \[\leadsto \frac{1}{N + \color{blue}{\left(\frac{1}{2} - \frac{1}{12} \cdot \frac{1}{N}\right)}} \]
12. Step-by-step derivation

    1. sub-neg N/A

       \[\leadsto \frac{1}{N + \color{blue}{\left(\frac{1}{2} + \left(\mathsf{neg}\left(\frac{1}{12} \cdot \frac{1}{N}\right)\right)\right)}} \]

    2. +-lowering-+.f64 N/A

       \[\leadsto \frac{1}{N + \color{blue}{\left(\frac{1}{2} + \left(\mathsf{neg}\left(\frac{1}{12} \cdot \frac{1}{N}\right)\right)\right)}} \]

    3. associate-*r/ N/A

       \[\leadsto \frac{1}{N + \left(\frac{1}{2} + \left(\mathsf{neg}\left(\color{blue}{\frac{\frac{1}{12} \cdot 1}{N}}\right)\right)\right)} \]

    4. metadata-eval N/A

       \[\leadsto \frac{1}{N + \left(\frac{1}{2} + \left(\mathsf{neg}\left(\frac{\color{blue}{\frac{1}{12}}}{N}\right)\right)\right)} \]

    5. distribute-neg-frac N/A

       \[\leadsto \frac{1}{N + \left(\frac{1}{2} + \color{blue}{\frac{\mathsf{neg}\left(\frac{1}{12}\right)}{N}}\right)} \]

    6. metadata-eval N/A

       \[\leadsto \frac{1}{N + \left(\frac{1}{2} + \frac{\color{blue}{\frac{-1}{12}}}{N}\right)} \]

    7. /-lowering-/.f64 96.0

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

13. Simplified 96.0%

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

Alternative 8: 93.1% accurate, 13.8× speedup

Math

\[\begin{array}{l} \\ \frac{1}{N + 0.5} \end{array} \]

FPCore

(FPCore (N) :precision binary64 (/ 1.0 (+ N 0.5)))

C

double code(double N) {
	return 1.0 / (N + 0.5);
}

Fortran

real(8) function code(n)
    real(8), intent (in) :: n
    code = 1.0d0 / (n + 0.5d0)
end function

Java

public static double code(double N) {
	return 1.0 / (N + 0.5);
}

Python

def code(N):
	return 1.0 / (N + 0.5)

Julia

function code(N)
	return Float64(1.0 / Float64(N + 0.5))
end

MATLAB

function tmp = code(N)
	tmp = 1.0 / (N + 0.5);
end

Wolfram

code[N_] := N[(1.0 / N[(N + 0.5), $MachinePrecision]), $MachinePrecision]

Derivation

1. Initial program 22.7%

   \[\log \left(N + 1\right) - \log N \]
2. Add Preprocessing

3. Taylor expanded in N around inf

   \[\leadsto \color{blue}{\frac{\left(1 + \frac{\frac{1}{3}}{{N}^{2}}\right) - \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{4} \cdot \frac{1}{{N}^{3}}\right)}{N}} \]

5. Simplified 96.7%

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

   1. clear-num N/A

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   2. /-lowering-/.f64 N/A

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   3. /-lowering-/.f64 N/A

      \[\leadsto \frac{1}{\color{blue}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   4. +-lowering-+.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{\color{blue}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   5. /-lowering-/.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{1 + \color{blue}{\frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   6. --lowering--.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{1 + \frac{\color{blue}{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}}{N}}} \]

   7. /-lowering-/.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \color{blue}{\frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}}{N}}} \]

   8. +-lowering-+.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\color{blue}{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}}{N}}{N}}} \]

   9. /-lowering-/.f64 96.8

      \[\leadsto \frac{1}{\frac{N}{1 + \frac{-0.5 - \frac{\color{blue}{\frac{0.25}{N}} + -0.3333333333333333}{N}}{N}}} \]

7. Applied egg-rr 96.8%

   \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{-0.5 - \frac{\frac{0.25}{N} + -0.3333333333333333}{N}}{N}}}} \]

8. Taylor expanded in N around inf

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

   1. distribute-rgt-in N/A

      \[\leadsto \frac{1}{\color{blue}{1 \cdot N + \left(\frac{1}{2} \cdot \frac{1}{N}\right) \cdot N}} \]

   2. *-lft-identity N/A

      \[\leadsto \frac{1}{\color{blue}{N} + \left(\frac{1}{2} \cdot \frac{1}{N}\right) \cdot N} \]

   3. associate-*l* N/A

      \[\leadsto \frac{1}{N + \color{blue}{\frac{1}{2} \cdot \left(\frac{1}{N} \cdot N\right)}} \]

   4. lft-mult-inverse N/A

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

   5. metadata-eval N/A

      \[\leadsto \frac{1}{N + \color{blue}{\frac{1}{2}}} \]

   6. +-lowering-+.f64 93.6

      \[\leadsto \frac{1}{\color{blue}{N + 0.5}} \]

10. Simplified 93.6%

    \[\leadsto \frac{1}{\color{blue}{N + 0.5}} \]
11. Add Preprocessing

Alternative 9: 84.6% accurate, 17.3× speedup

Math

\[\begin{array}{l} \\ \frac{1}{N} \end{array} \]

FPCore

(FPCore (N) :precision binary64 (/ 1.0 N))

C

double code(double N) {
	return 1.0 / N;
}

Fortran

real(8) function code(n)
    real(8), intent (in) :: n
    code = 1.0d0 / n
end function

Java

public static double code(double N) {
	return 1.0 / N;
}

Python

def code(N):
	return 1.0 / N

Julia

function code(N)
	return Float64(1.0 / N)
end

MATLAB

function tmp = code(N)
	tmp = 1.0 / N;
end

Wolfram

code[N_] := N[(1.0 / N), $MachinePrecision]

Derivation

1. Initial program 22.7%

   \[\log \left(N + 1\right) - \log N \]
2. Add Preprocessing

3. Taylor expanded in N around inf

   \[\leadsto \color{blue}{\frac{1}{N}} \]
4. Step-by-step derivation

   1. /-lowering-/.f64 85.2

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

5. Simplified 85.2%

   \[\leadsto \color{blue}{\frac{1}{N}} \]
6. Add Preprocessing

Alternative 10: 9.9% accurate, 207.0× speedup

Math

\[\begin{array}{l} \\ 2 \end{array} \]

FPCore

(FPCore (N) :precision binary64 2.0)

C

double code(double N) {
	return 2.0;
}

Fortran

real(8) function code(n)
    real(8), intent (in) :: n
    code = 2.0d0
end function

Java

public static double code(double N) {
	return 2.0;
}

Python

def code(N):
	return 2.0

Julia

function code(N)
	return 2.0
end

MATLAB

function tmp = code(N)
	tmp = 2.0;
end

Wolfram

code[N_] := 2.0

Derivation

1. Initial program 22.7%

   \[\log \left(N + 1\right) - \log N \]
2. Add Preprocessing

3. Taylor expanded in N around inf

   \[\leadsto \color{blue}{\frac{\left(1 + \frac{\frac{1}{3}}{{N}^{2}}\right) - \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{4} \cdot \frac{1}{{N}^{3}}\right)}{N}} \]

5. Simplified 96.7%

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

   1. clear-num N/A

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   2. /-lowering-/.f64 N/A

      \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   3. /-lowering-/.f64 N/A

      \[\leadsto \frac{1}{\color{blue}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   4. +-lowering-+.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{\color{blue}{1 + \frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   5. /-lowering-/.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{1 + \color{blue}{\frac{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}{N}}}} \]

   6. --lowering--.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{1 + \frac{\color{blue}{\frac{-1}{2} - \frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}}{N}}} \]

   7. /-lowering-/.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \color{blue}{\frac{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}{N}}}{N}}} \]

   8. +-lowering-+.f64 N/A

      \[\leadsto \frac{1}{\frac{N}{1 + \frac{\frac{-1}{2} - \frac{\color{blue}{\frac{\frac{1}{4}}{N} + \frac{-1}{3}}}{N}}{N}}} \]

   9. /-lowering-/.f64 96.8

      \[\leadsto \frac{1}{\frac{N}{1 + \frac{-0.5 - \frac{\color{blue}{\frac{0.25}{N}} + -0.3333333333333333}{N}}{N}}} \]

7. Applied egg-rr 96.8%

   \[\leadsto \color{blue}{\frac{1}{\frac{N}{1 + \frac{-0.5 - \frac{\frac{0.25}{N} + -0.3333333333333333}{N}}{N}}}} \]

8. Taylor expanded in N around inf

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

   1. distribute-rgt-in N/A

      \[\leadsto \frac{1}{\color{blue}{1 \cdot N + \left(\frac{1}{2} \cdot \frac{1}{N}\right) \cdot N}} \]

   2. *-lft-identity N/A

      \[\leadsto \frac{1}{\color{blue}{N} + \left(\frac{1}{2} \cdot \frac{1}{N}\right) \cdot N} \]

   3. associate-*l* N/A

      \[\leadsto \frac{1}{N + \color{blue}{\frac{1}{2} \cdot \left(\frac{1}{N} \cdot N\right)}} \]

   4. lft-mult-inverse N/A

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

   5. metadata-eval N/A

      \[\leadsto \frac{1}{N + \color{blue}{\frac{1}{2}}} \]

   6. +-lowering-+.f64 93.6

      \[\leadsto \frac{1}{\color{blue}{N + 0.5}} \]

10. Simplified 93.6%

    \[\leadsto \frac{1}{\color{blue}{N + 0.5}} \]

11. Taylor expanded in N around 0

    \[\leadsto \color{blue}{2} \]
12. Step-by-step derivation

13. Simplified 9.8%

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

Developer Target 1: 99.8% accurate, 1.8× speedup

Math

\[\begin{array}{l} \\ \mathsf{log1p}\left(\frac{1}{N}\right) \end{array} \]

FPCore

(FPCore (N) :precision binary64 (log1p (/ 1.0 N)))

C

double code(double N) {
	return log1p((1.0 / N));
}

Java

public static double code(double N) {
	return Math.log1p((1.0 / N));
}

Python

def code(N):
	return math.log1p((1.0 / N))

Julia

function code(N)
	return log1p(Float64(1.0 / N))
end

Wolfram

code[N_] := N[Log[1 + N[(1.0 / N), $MachinePrecision]], $MachinePrecision]

Developer Target 2: 26.3% accurate, 1.8× speedup

Math

\[\begin{array}{l} \\ \log \left(1 + \frac{1}{N}\right) \end{array} \]

FPCore

(FPCore (N) :precision binary64 (log (+ 1.0 (/ 1.0 N))))

C

double code(double N) {
	return log((1.0 + (1.0 / N)));
}

Fortran

real(8) function code(n)
    real(8), intent (in) :: n
    code = log((1.0d0 + (1.0d0 / n)))
end function

Java

public static double code(double N) {
	return Math.log((1.0 + (1.0 / N)));
}

Python

def code(N):
	return math.log((1.0 + (1.0 / N)))

Julia

function code(N)
	return log(Float64(1.0 + Float64(1.0 / N)))
end

MATLAB

function tmp = code(N)
	tmp = log((1.0 + (1.0 / N)));
end

Wolfram

code[N_] := N[Log[N[(1.0 + N[(1.0 / N), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]

Developer Target 3: 96.2% accurate, 0.6× speedup

Math

\[\begin{array}{l} \\ \left(\left(\frac{1}{N} + \frac{-1}{2 \cdot {N}^{2}}\right) + \frac{1}{3 \cdot {N}^{3}}\right) + \frac{-1}{4 \cdot {N}^{4}} \end{array} \]

FPCore

(FPCore (N)
 :precision binary64
 (+
  (+ (+ (/ 1.0 N) (/ -1.0 (* 2.0 (pow N 2.0)))) (/ 1.0 (* 3.0 (pow N 3.0))))
  (/ -1.0 (* 4.0 (pow N 4.0)))))

C

double code(double N) {
	return (((1.0 / N) + (-1.0 / (2.0 * pow(N, 2.0)))) + (1.0 / (3.0 * pow(N, 3.0)))) + (-1.0 / (4.0 * pow(N, 4.0)));
}

Fortran

real(8) function code(n)
    real(8), intent (in) :: n
    code = (((1.0d0 / n) + ((-1.0d0) / (2.0d0 * (n ** 2.0d0)))) + (1.0d0 / (3.0d0 * (n ** 3.0d0)))) + ((-1.0d0) / (4.0d0 * (n ** 4.0d0)))
end function

Java

public static double code(double N) {
	return (((1.0 / N) + (-1.0 / (2.0 * Math.pow(N, 2.0)))) + (1.0 / (3.0 * Math.pow(N, 3.0)))) + (-1.0 / (4.0 * Math.pow(N, 4.0)));
}

Python

def code(N):
	return (((1.0 / N) + (-1.0 / (2.0 * math.pow(N, 2.0)))) + (1.0 / (3.0 * math.pow(N, 3.0)))) + (-1.0 / (4.0 * math.pow(N, 4.0)))

Julia

function code(N)
	return Float64(Float64(Float64(Float64(1.0 / N) + Float64(-1.0 / Float64(2.0 * (N ^ 2.0)))) + Float64(1.0 / Float64(3.0 * (N ^ 3.0)))) + Float64(-1.0 / Float64(4.0 * (N ^ 4.0))))
end

MATLAB

function tmp = code(N)
	tmp = (((1.0 / N) + (-1.0 / (2.0 * (N ^ 2.0)))) + (1.0 / (3.0 * (N ^ 3.0)))) + (-1.0 / (4.0 * (N ^ 4.0)));
end

Wolfram

code[N_] := N[(N[(N[(N[(1.0 / N), $MachinePrecision] + N[(-1.0 / N[(2.0 * N[Power[N, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(1.0 / N[(3.0 * N[Power[N, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-1.0 / N[(4.0 * N[Power[N, 4.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]

Reproduce

herbie shell --seed 2024205 
(FPCore (N)
  :name "2log (problem 3.3.6)"
  :precision binary64
  :pre (and (> N 1.0) (< N 1e+40))

  :alt
  (! :herbie-platform default (log1p (/ 1 N)))

  :alt
  (! :herbie-platform default (log (+ 1 (/ 1 N))))

  :alt
  (! :herbie-platform default (+ (/ 1 N) (/ -1 (* 2 (pow N 2))) (/ 1 (* 3 (pow N 3))) (/ -1 (* 4 (pow N 4)))))

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