2log (problem 3.3.6)

Percentage Accurate: 24.2% → 99.4%
Time: 8.3s
Alternatives: 11
Speedup: 8.0×

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 11 alternatives:

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

Initial Program: 24.2% 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: 99.4% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\log \left(N + 1\right) - \log N \leq 0.001:\\ \;\;\;\;\frac{\frac{-0.5 - \frac{\mathsf{fma}\left(-0.3333333333333333, N, 0.25\right)}{N \cdot N}}{N} - -1}{N}\\ \mathbf{else}:\\ \;\;\;\;-\log \left(\frac{N}{1 + N}\right)\\ \end{array} \end{array} \]
(FPCore (N)
 :precision binary64
 (if (<= (- (log (+ N 1.0)) (log N)) 0.001)
   (/ (- (/ (- -0.5 (/ (fma -0.3333333333333333 N 0.25) (* N N))) N) -1.0) N)
   (- (log (/ N (+ 1.0 N))))))
double code(double N) {
	double tmp;
	if ((log((N + 1.0)) - log(N)) <= 0.001) {
		tmp = (((-0.5 - (fma(-0.3333333333333333, N, 0.25) / (N * N))) / N) - -1.0) / N;
	} else {
		tmp = -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(Float64(Float64(Float64(-0.5 - Float64(fma(-0.3333333333333333, N, 0.25) / Float64(N * N))) / N) - -1.0) / N);
	else
		tmp = Float64(-log(Float64(N / Float64(1.0 + N))));
	end
	return tmp
end
code[N_] := If[LessEqual[N[(N[Log[N[(N + 1.0), $MachinePrecision]], $MachinePrecision] - N[Log[N], $MachinePrecision]), $MachinePrecision], 0.001], N[(N[(N[(N[(-0.5 - N[(N[(-0.3333333333333333 * N + 0.25), $MachinePrecision] / N[(N * N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N), $MachinePrecision] - -1.0), $MachinePrecision] / N), $MachinePrecision], (-N[Log[N[(N / N[(1.0 + N), $MachinePrecision]), $MachinePrecision]], $MachinePrecision])]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\log \left(N + 1\right) - \log N \leq 0.001:\\
\;\;\;\;\frac{\frac{-0.5 - \frac{\mathsf{fma}\left(-0.3333333333333333, N, 0.25\right)}{N \cdot N}}{N} - -1}{N}\\

\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 18.2%

      \[\log \left(N + 1\right) - \log N \]
    2. Add Preprocessing
    3. Taylor expanded in N around inf

      \[\leadsto \color{blue}{\frac{\left(1 + \frac{\frac{1}{3}}{{N}^{2}}\right) - \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{4} \cdot \frac{1}{{N}^{3}}\right)}{N}} \]
    4. Applied rewrites99.7%

      \[\leadsto \color{blue}{\frac{\frac{-0.5 - \frac{\frac{0.25}{N} - 0.3333333333333333}{N}}{N} - -1}{N}} \]
    5. Taylor expanded in N around 0

      \[\leadsto \frac{\frac{\frac{-1}{2} - \frac{\frac{1}{4} + \frac{-1}{3} \cdot N}{{N}^{2}}}{N} - -1}{N} \]
    6. Step-by-step derivation
      1. Applied rewrites99.7%

        \[\leadsto \frac{\frac{-0.5 - \frac{\mathsf{fma}\left(-0.3333333333333333, N, 0.25\right)}{N \cdot N}}{N} - -1}{N} \]

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

      1. Initial program 91.6%

        \[\log \left(N + 1\right) - \log N \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift--.f64N/A

          \[\leadsto \color{blue}{\log \left(N + 1\right) - \log N} \]
        2. lift-log.f64N/A

          \[\leadsto \color{blue}{\log \left(N + 1\right)} - \log N \]
        3. lift-log.f64N/A

          \[\leadsto \log \left(N + 1\right) - \color{blue}{\log N} \]
        4. diff-logN/A

          \[\leadsto \color{blue}{\log \left(\frac{N + 1}{N}\right)} \]
        5. clear-numN/A

          \[\leadsto \log \color{blue}{\left(\frac{1}{\frac{N}{N + 1}}\right)} \]
        6. clear-numN/A

          \[\leadsto \log \color{blue}{\left(\frac{1}{\frac{\frac{N}{N + 1}}{1}}\right)} \]
        7. log-recN/A

          \[\leadsto \color{blue}{\mathsf{neg}\left(\log \left(\frac{\frac{N}{N + 1}}{1}\right)\right)} \]
        8. lower-neg.f64N/A

          \[\leadsto \color{blue}{-\log \left(\frac{\frac{N}{N + 1}}{1}\right)} \]
        9. lower-log.f64N/A

          \[\leadsto -\color{blue}{\log \left(\frac{\frac{N}{N + 1}}{1}\right)} \]
        10. lower-/.f64N/A

          \[\leadsto -\log \color{blue}{\left(\frac{\frac{N}{N + 1}}{1}\right)} \]
        11. lower-/.f6495.0

          \[\leadsto -\log \left(\frac{\color{blue}{\frac{N}{N + 1}}}{1}\right) \]
        12. lift-+.f64N/A

          \[\leadsto -\log \left(\frac{\frac{N}{\color{blue}{N + 1}}}{1}\right) \]
        13. +-commutativeN/A

          \[\leadsto -\log \left(\frac{\frac{N}{\color{blue}{1 + N}}}{1}\right) \]
        14. lower-+.f6495.0

          \[\leadsto -\log \left(\frac{\frac{N}{\color{blue}{1 + N}}}{1}\right) \]
      4. Applied rewrites95.0%

        \[\leadsto \color{blue}{-\log \left(\frac{\frac{N}{1 + N}}{1}\right)} \]
    7. Recombined 2 regimes into one program.
    8. Final simplification99.5%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\log \left(N + 1\right) - \log N \leq 0.001:\\ \;\;\;\;\frac{\frac{-0.5 - \frac{\mathsf{fma}\left(-0.3333333333333333, N, 0.25\right)}{N \cdot N}}{N} - -1}{N}\\ \mathbf{else}:\\ \;\;\;\;-\log \left(\frac{N}{1 + N}\right)\\ \end{array} \]
    9. Add Preprocessing

    Alternative 2: 99.3% accurate, 0.5× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\log \left(N + 1\right) - \log N \leq 0.001:\\ \;\;\;\;\frac{\frac{-0.5 - \frac{\mathsf{fma}\left(-0.3333333333333333, N, 0.25\right)}{N \cdot N}}{N} - -1}{N}\\ \mathbf{else}:\\ \;\;\;\;\log \left({N}^{-1} + 1\right)\\ \end{array} \end{array} \]
    (FPCore (N)
     :precision binary64
     (if (<= (- (log (+ N 1.0)) (log N)) 0.001)
       (/ (- (/ (- -0.5 (/ (fma -0.3333333333333333 N 0.25) (* N N))) N) -1.0) N)
       (log (+ (pow N -1.0) 1.0))))
    double code(double N) {
    	double tmp;
    	if ((log((N + 1.0)) - log(N)) <= 0.001) {
    		tmp = (((-0.5 - (fma(-0.3333333333333333, N, 0.25) / (N * N))) / N) - -1.0) / N;
    	} else {
    		tmp = log((pow(N, -1.0) + 1.0));
    	}
    	return tmp;
    }
    
    function code(N)
    	tmp = 0.0
    	if (Float64(log(Float64(N + 1.0)) - log(N)) <= 0.001)
    		tmp = Float64(Float64(Float64(Float64(-0.5 - Float64(fma(-0.3333333333333333, N, 0.25) / Float64(N * N))) / N) - -1.0) / N);
    	else
    		tmp = log(Float64((N ^ -1.0) + 1.0));
    	end
    	return tmp
    end
    
    code[N_] := If[LessEqual[N[(N[Log[N[(N + 1.0), $MachinePrecision]], $MachinePrecision] - N[Log[N], $MachinePrecision]), $MachinePrecision], 0.001], N[(N[(N[(N[(-0.5 - N[(N[(-0.3333333333333333 * N + 0.25), $MachinePrecision] / N[(N * N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N), $MachinePrecision] - -1.0), $MachinePrecision] / N), $MachinePrecision], N[Log[N[(N[Power[N, -1.0], $MachinePrecision] + 1.0), $MachinePrecision]], $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;\log \left(N + 1\right) - \log N \leq 0.001:\\
    \;\;\;\;\frac{\frac{-0.5 - \frac{\mathsf{fma}\left(-0.3333333333333333, N, 0.25\right)}{N \cdot N}}{N} - -1}{N}\\
    
    \mathbf{else}:\\
    \;\;\;\;\log \left({N}^{-1} + 1\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 18.2%

        \[\log \left(N + 1\right) - \log N \]
      2. Add Preprocessing
      3. Taylor expanded in N around inf

        \[\leadsto \color{blue}{\frac{\left(1 + \frac{\frac{1}{3}}{{N}^{2}}\right) - \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{4} \cdot \frac{1}{{N}^{3}}\right)}{N}} \]
      4. Applied rewrites99.7%

        \[\leadsto \color{blue}{\frac{\frac{-0.5 - \frac{\frac{0.25}{N} - 0.3333333333333333}{N}}{N} - -1}{N}} \]
      5. Taylor expanded in N around 0

        \[\leadsto \frac{\frac{\frac{-1}{2} - \frac{\frac{1}{4} + \frac{-1}{3} \cdot N}{{N}^{2}}}{N} - -1}{N} \]
      6. Step-by-step derivation
        1. Applied rewrites99.7%

          \[\leadsto \frac{\frac{-0.5 - \frac{\mathsf{fma}\left(-0.3333333333333333, N, 0.25\right)}{N \cdot N}}{N} - -1}{N} \]

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

        1. Initial program 91.6%

          \[\log \left(N + 1\right) - \log N \]
        2. Add Preprocessing
        3. Step-by-step derivation
          1. lift--.f64N/A

            \[\leadsto \color{blue}{\log \left(N + 1\right) - \log N} \]
          2. lift-log.f64N/A

            \[\leadsto \color{blue}{\log \left(N + 1\right)} - \log N \]
          3. lift-log.f64N/A

            \[\leadsto \log \left(N + 1\right) - \color{blue}{\log N} \]
          4. diff-logN/A

            \[\leadsto \color{blue}{\log \left(\frac{N + 1}{N}\right)} \]
          5. lower-log.f64N/A

            \[\leadsto \color{blue}{\log \left(\frac{N + 1}{N}\right)} \]
          6. lower-/.f6493.3

            \[\leadsto \log \color{blue}{\left(\frac{N + 1}{N}\right)} \]
          7. lift-+.f64N/A

            \[\leadsto \log \left(\frac{\color{blue}{N + 1}}{N}\right) \]
          8. +-commutativeN/A

            \[\leadsto \log \left(\frac{\color{blue}{1 + N}}{N}\right) \]
          9. lower-+.f6493.3

            \[\leadsto \log \left(\frac{\color{blue}{1 + N}}{N}\right) \]
        4. Applied rewrites93.3%

          \[\leadsto \color{blue}{\log \left(\frac{1 + N}{N}\right)} \]
        5. Taylor expanded in N around inf

          \[\leadsto \log \color{blue}{\left(1 + \frac{1}{N}\right)} \]
        6. Step-by-step derivation
          1. +-commutativeN/A

            \[\leadsto \log \color{blue}{\left(\frac{1}{N} + 1\right)} \]
          2. lower-+.f64N/A

            \[\leadsto \log \color{blue}{\left(\frac{1}{N} + 1\right)} \]
          3. lower-/.f6493.3

            \[\leadsto \log \left(\color{blue}{\frac{1}{N}} + 1\right) \]
        7. Applied rewrites93.3%

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

        \[\leadsto \begin{array}{l} \mathbf{if}\;\log \left(N + 1\right) - \log N \leq 0.001:\\ \;\;\;\;\frac{\frac{-0.5 - \frac{\mathsf{fma}\left(-0.3333333333333333, N, 0.25\right)}{N \cdot N}}{N} - -1}{N}\\ \mathbf{else}:\\ \;\;\;\;\log \left({N}^{-1} + 1\right)\\ \end{array} \]
      9. Add Preprocessing

      Alternative 3: 99.3% accurate, 0.6× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\log \left(N + 1\right) - \log N \leq 0.001:\\ \;\;\;\;\frac{\frac{-0.5 - \frac{\mathsf{fma}\left(-0.3333333333333333, N, 0.25\right)}{N \cdot N}}{N} - -1}{N}\\ \mathbf{else}:\\ \;\;\;\;-\log \left(\frac{\left(N - 1\right) \cdot N}{\mathsf{fma}\left(N, N, -1\right)}\right)\\ \end{array} \end{array} \]
      (FPCore (N)
       :precision binary64
       (if (<= (- (log (+ N 1.0)) (log N)) 0.001)
         (/ (- (/ (- -0.5 (/ (fma -0.3333333333333333 N 0.25) (* N N))) N) -1.0) N)
         (- (log (/ (* (- N 1.0) N) (fma N N -1.0))))))
      double code(double N) {
      	double tmp;
      	if ((log((N + 1.0)) - log(N)) <= 0.001) {
      		tmp = (((-0.5 - (fma(-0.3333333333333333, N, 0.25) / (N * N))) / N) - -1.0) / N;
      	} else {
      		tmp = -log((((N - 1.0) * N) / fma(N, N, -1.0)));
      	}
      	return tmp;
      }
      
      function code(N)
      	tmp = 0.0
      	if (Float64(log(Float64(N + 1.0)) - log(N)) <= 0.001)
      		tmp = Float64(Float64(Float64(Float64(-0.5 - Float64(fma(-0.3333333333333333, N, 0.25) / Float64(N * N))) / N) - -1.0) / N);
      	else
      		tmp = Float64(-log(Float64(Float64(Float64(N - 1.0) * N) / fma(N, N, -1.0))));
      	end
      	return tmp
      end
      
      code[N_] := If[LessEqual[N[(N[Log[N[(N + 1.0), $MachinePrecision]], $MachinePrecision] - N[Log[N], $MachinePrecision]), $MachinePrecision], 0.001], N[(N[(N[(N[(-0.5 - N[(N[(-0.3333333333333333 * N + 0.25), $MachinePrecision] / N[(N * N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N), $MachinePrecision] - -1.0), $MachinePrecision] / N), $MachinePrecision], (-N[Log[N[(N[(N[(N - 1.0), $MachinePrecision] * N), $MachinePrecision] / N[(N * N + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision])]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;\log \left(N + 1\right) - \log N \leq 0.001:\\
      \;\;\;\;\frac{\frac{-0.5 - \frac{\mathsf{fma}\left(-0.3333333333333333, N, 0.25\right)}{N \cdot N}}{N} - -1}{N}\\
      
      \mathbf{else}:\\
      \;\;\;\;-\log \left(\frac{\left(N - 1\right) \cdot N}{\mathsf{fma}\left(N, N, -1\right)}\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 18.2%

          \[\log \left(N + 1\right) - \log N \]
        2. Add Preprocessing
        3. Taylor expanded in N around inf

          \[\leadsto \color{blue}{\frac{\left(1 + \frac{\frac{1}{3}}{{N}^{2}}\right) - \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{4} \cdot \frac{1}{{N}^{3}}\right)}{N}} \]
        4. Applied rewrites99.7%

          \[\leadsto \color{blue}{\frac{\frac{-0.5 - \frac{\frac{0.25}{N} - 0.3333333333333333}{N}}{N} - -1}{N}} \]
        5. Taylor expanded in N around 0

          \[\leadsto \frac{\frac{\frac{-1}{2} - \frac{\frac{1}{4} + \frac{-1}{3} \cdot N}{{N}^{2}}}{N} - -1}{N} \]
        6. Step-by-step derivation
          1. Applied rewrites99.7%

            \[\leadsto \frac{\frac{-0.5 - \frac{\mathsf{fma}\left(-0.3333333333333333, N, 0.25\right)}{N \cdot N}}{N} - -1}{N} \]

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

          1. Initial program 91.6%

            \[\log \left(N + 1\right) - \log N \]
          2. Add Preprocessing
          3. Step-by-step derivation
            1. lift--.f64N/A

              \[\leadsto \color{blue}{\log \left(N + 1\right) - \log N} \]
            2. lift-log.f64N/A

              \[\leadsto \color{blue}{\log \left(N + 1\right)} - \log N \]
            3. lift-log.f64N/A

              \[\leadsto \log \left(N + 1\right) - \color{blue}{\log N} \]
            4. diff-logN/A

              \[\leadsto \color{blue}{\log \left(\frac{N + 1}{N}\right)} \]
            5. lift-+.f64N/A

              \[\leadsto \log \left(\frac{\color{blue}{N + 1}}{N}\right) \]
            6. flip-+N/A

              \[\leadsto \log \left(\frac{\color{blue}{\frac{N \cdot N - 1 \cdot 1}{N - 1}}}{N}\right) \]
            7. associate-/l/N/A

              \[\leadsto \log \color{blue}{\left(\frac{N \cdot N - 1 \cdot 1}{N \cdot \left(N - 1\right)}\right)} \]
            8. clear-numN/A

              \[\leadsto \log \color{blue}{\left(\frac{1}{\frac{N \cdot \left(N - 1\right)}{N \cdot N - 1 \cdot 1}}\right)} \]
            9. log-recN/A

              \[\leadsto \color{blue}{\mathsf{neg}\left(\log \left(\frac{N \cdot \left(N - 1\right)}{N \cdot N - 1 \cdot 1}\right)\right)} \]
            10. lower-neg.f64N/A

              \[\leadsto \color{blue}{-\log \left(\frac{N \cdot \left(N - 1\right)}{N \cdot N - 1 \cdot 1}\right)} \]
            11. lower-log.f64N/A

              \[\leadsto -\color{blue}{\log \left(\frac{N \cdot \left(N - 1\right)}{N \cdot N - 1 \cdot 1}\right)} \]
            12. distribute-rgt-out--N/A

              \[\leadsto -\log \left(\frac{\color{blue}{N \cdot N - 1 \cdot N}}{N \cdot N - 1 \cdot 1}\right) \]
            13. lower-/.f64N/A

              \[\leadsto -\log \color{blue}{\left(\frac{N \cdot N - 1 \cdot N}{N \cdot N - 1 \cdot 1}\right)} \]
            14. distribute-rgt-out--N/A

              \[\leadsto -\log \left(\frac{\color{blue}{N \cdot \left(N - 1\right)}}{N \cdot N - 1 \cdot 1}\right) \]
            15. *-commutativeN/A

              \[\leadsto -\log \left(\frac{\color{blue}{\left(N - 1\right) \cdot N}}{N \cdot N - 1 \cdot 1}\right) \]
            16. lower-*.f64N/A

              \[\leadsto -\log \left(\frac{\color{blue}{\left(N - 1\right) \cdot N}}{N \cdot N - 1 \cdot 1}\right) \]
            17. lower--.f64N/A

              \[\leadsto -\log \left(\frac{\color{blue}{\left(N - 1\right)} \cdot N}{N \cdot N - 1 \cdot 1}\right) \]
            18. metadata-evalN/A

              \[\leadsto -\log \left(\frac{\left(N - 1\right) \cdot N}{N \cdot N - \color{blue}{1}}\right) \]
            19. sub-negN/A

              \[\leadsto -\log \left(\frac{\left(N - 1\right) \cdot N}{\color{blue}{N \cdot N + \left(\mathsf{neg}\left(1\right)\right)}}\right) \]
            20. lower-fma.f64N/A

              \[\leadsto -\log \left(\frac{\left(N - 1\right) \cdot N}{\color{blue}{\mathsf{fma}\left(N, N, \mathsf{neg}\left(1\right)\right)}}\right) \]
            21. metadata-eval94.5

              \[\leadsto -\log \left(\frac{\left(N - 1\right) \cdot N}{\mathsf{fma}\left(N, N, \color{blue}{-1}\right)}\right) \]
          4. Applied rewrites94.5%

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

        Alternative 4: 96.7% accurate, 1.3× speedup?

        \[\begin{array}{l} \\ {\left(\mathsf{fma}\left(\frac{0.5 - \frac{0.08333333333333333 - \frac{0.041666666666666664}{N}}{N}}{N}, -1, -1\right) \cdot \left(-N\right)\right)}^{-1} \end{array} \]
        (FPCore (N)
         :precision binary64
         (pow
          (*
           (fma
            (/ (- 0.5 (/ (- 0.08333333333333333 (/ 0.041666666666666664 N)) N)) N)
            -1.0
            -1.0)
           (- N))
          -1.0))
        double code(double N) {
        	return pow((fma(((0.5 - ((0.08333333333333333 - (0.041666666666666664 / N)) / N)) / N), -1.0, -1.0) * -N), -1.0);
        }
        
        function code(N)
        	return Float64(fma(Float64(Float64(0.5 - Float64(Float64(0.08333333333333333 - Float64(0.041666666666666664 / N)) / N)) / N), -1.0, -1.0) * Float64(-N)) ^ -1.0
        end
        
        code[N_] := N[Power[N[(N[(N[(N[(0.5 - N[(N[(0.08333333333333333 - N[(0.041666666666666664 / N), $MachinePrecision]), $MachinePrecision] / N), $MachinePrecision]), $MachinePrecision] / N), $MachinePrecision] * -1.0 + -1.0), $MachinePrecision] * (-N)), $MachinePrecision], -1.0], $MachinePrecision]
        
        \begin{array}{l}
        
        \\
        {\left(\mathsf{fma}\left(\frac{0.5 - \frac{0.08333333333333333 - \frac{0.041666666666666664}{N}}{N}}{N}, -1, -1\right) \cdot \left(-N\right)\right)}^{-1}
        \end{array}
        
        Derivation
        1. Initial program 21.9%

          \[\log \left(N + 1\right) - \log N \]
        2. Add Preprocessing
        3. Taylor expanded in N around inf

          \[\leadsto \color{blue}{\frac{\left(1 + \frac{\frac{1}{3}}{{N}^{2}}\right) - \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{4} \cdot \frac{1}{{N}^{3}}\right)}{N}} \]
        4. Applied rewrites97.5%

          \[\leadsto \color{blue}{\frac{\frac{-0.5 - \frac{\frac{0.25}{N} - 0.3333333333333333}{N}}{N} - -1}{N}} \]
        5. Step-by-step derivation
          1. Applied rewrites97.5%

            \[\leadsto \frac{1}{\color{blue}{\frac{N}{\frac{-0.5 - \frac{\frac{0.25}{N} - 0.3333333333333333}{N}}{N} - -1}}} \]
          2. Taylor expanded in N around -inf

            \[\leadsto \frac{1}{-1 \cdot \color{blue}{\left(N \cdot \left(-1 \cdot \frac{\frac{1}{2} + -1 \cdot \frac{\frac{1}{12} - \frac{1}{24} \cdot \frac{1}{N}}{N}}{N} - 1\right)\right)}} \]
          3. Step-by-step derivation
            1. Applied rewrites97.7%

              \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{0.5 - \frac{0.08333333333333333 - \frac{0.041666666666666664}{N}}{N}}{N}, -1, -1\right) \cdot \color{blue}{\left(-N\right)}} \]
            2. Final simplification97.7%

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

            Alternative 5: 95.5% accurate, 1.5× speedup?

            \[\begin{array}{l} \\ {\left(\left(\frac{0.5 - \frac{0.08333333333333333}{N}}{N} + 1\right) \cdot N\right)}^{-1} \end{array} \]
            (FPCore (N)
             :precision binary64
             (pow (* (+ (/ (- 0.5 (/ 0.08333333333333333 N)) N) 1.0) N) -1.0))
            double code(double N) {
            	return pow(((((0.5 - (0.08333333333333333 / N)) / N) + 1.0) * N), -1.0);
            }
            
            real(8) function code(n)
                real(8), intent (in) :: n
                code = ((((0.5d0 - (0.08333333333333333d0 / n)) / n) + 1.0d0) * n) ** (-1.0d0)
            end function
            
            public static double code(double N) {
            	return Math.pow(((((0.5 - (0.08333333333333333 / N)) / N) + 1.0) * N), -1.0);
            }
            
            def code(N):
            	return math.pow(((((0.5 - (0.08333333333333333 / N)) / N) + 1.0) * N), -1.0)
            
            function code(N)
            	return Float64(Float64(Float64(Float64(0.5 - Float64(0.08333333333333333 / N)) / N) + 1.0) * N) ^ -1.0
            end
            
            function tmp = code(N)
            	tmp = ((((0.5 - (0.08333333333333333 / N)) / N) + 1.0) * N) ^ -1.0;
            end
            
            code[N_] := N[Power[N[(N[(N[(N[(0.5 - N[(0.08333333333333333 / N), $MachinePrecision]), $MachinePrecision] / N), $MachinePrecision] + 1.0), $MachinePrecision] * N), $MachinePrecision], -1.0], $MachinePrecision]
            
            \begin{array}{l}
            
            \\
            {\left(\left(\frac{0.5 - \frac{0.08333333333333333}{N}}{N} + 1\right) \cdot N\right)}^{-1}
            \end{array}
            
            Derivation
            1. Initial program 21.9%

              \[\log \left(N + 1\right) - \log N \]
            2. Add Preprocessing
            3. Taylor expanded in N around inf

              \[\leadsto \color{blue}{\frac{\left(1 + \frac{\frac{1}{3}}{{N}^{2}}\right) - \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{4} \cdot \frac{1}{{N}^{3}}\right)}{N}} \]
            4. Applied rewrites97.5%

              \[\leadsto \color{blue}{\frac{\frac{-0.5 - \frac{\frac{0.25}{N} - 0.3333333333333333}{N}}{N} - -1}{N}} \]
            5. Step-by-step derivation
              1. Applied rewrites97.5%

                \[\leadsto \frac{1}{\color{blue}{\frac{N}{\frac{-0.5 - \frac{\frac{0.25}{N} - 0.3333333333333333}{N}}{N} - -1}}} \]
              2. Taylor expanded in N around inf

                \[\leadsto \frac{1}{N \cdot \color{blue}{\left(\left(1 + \frac{1}{2} \cdot \frac{1}{N}\right) - \frac{\frac{1}{12}}{{N}^{2}}\right)}} \]
              3. Step-by-step derivation
                1. Applied rewrites96.5%

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

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

                Alternative 6: 92.9% accurate, 1.7× speedup?

                \[\begin{array}{l} \\ {\left(\mathsf{fma}\left(\frac{0.5}{N}, N, N\right)\right)}^{-1} \end{array} \]
                (FPCore (N) :precision binary64 (pow (fma (/ 0.5 N) N N) -1.0))
                double code(double N) {
                	return pow(fma((0.5 / N), N, N), -1.0);
                }
                
                function code(N)
                	return fma(Float64(0.5 / N), N, N) ^ -1.0
                end
                
                code[N_] := N[Power[N[(N[(0.5 / N), $MachinePrecision] * N + N), $MachinePrecision], -1.0], $MachinePrecision]
                
                \begin{array}{l}
                
                \\
                {\left(\mathsf{fma}\left(\frac{0.5}{N}, N, N\right)\right)}^{-1}
                \end{array}
                
                Derivation
                1. Initial program 21.9%

                  \[\log \left(N + 1\right) - \log N \]
                2. Add Preprocessing
                3. Taylor expanded in N around inf

                  \[\leadsto \color{blue}{\frac{\left(1 + \frac{\frac{1}{3}}{{N}^{2}}\right) - \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{4} \cdot \frac{1}{{N}^{3}}\right)}{N}} \]
                4. Applied rewrites97.5%

                  \[\leadsto \color{blue}{\frac{\frac{-0.5 - \frac{\frac{0.25}{N} - 0.3333333333333333}{N}}{N} - -1}{N}} \]
                5. Step-by-step derivation
                  1. Applied rewrites97.5%

                    \[\leadsto \frac{1}{\color{blue}{\frac{N}{\frac{-0.5 - \frac{\frac{0.25}{N} - 0.3333333333333333}{N}}{N} - -1}}} \]
                  2. Taylor expanded in N around inf

                    \[\leadsto \frac{1}{N \cdot \color{blue}{\left(1 + \frac{1}{2} \cdot \frac{1}{N}\right)}} \]
                  3. Step-by-step derivation
                    1. Applied rewrites94.0%

                      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{0.5}{N}, \color{blue}{N}, N\right)} \]
                    2. Final simplification94.0%

                      \[\leadsto {\left(\mathsf{fma}\left(\frac{0.5}{N}, N, N\right)\right)}^{-1} \]
                    3. Add Preprocessing

                    Alternative 7: 84.2% accurate, 2.0× speedup?

                    \[\begin{array}{l} \\ {N}^{-1} \end{array} \]
                    (FPCore (N) :precision binary64 (pow N -1.0))
                    double code(double N) {
                    	return pow(N, -1.0);
                    }
                    
                    real(8) function code(n)
                        real(8), intent (in) :: n
                        code = n ** (-1.0d0)
                    end function
                    
                    public static double code(double N) {
                    	return Math.pow(N, -1.0);
                    }
                    
                    def code(N):
                    	return math.pow(N, -1.0)
                    
                    function code(N)
                    	return N ^ -1.0
                    end
                    
                    function tmp = code(N)
                    	tmp = N ^ -1.0;
                    end
                    
                    code[N_] := N[Power[N, -1.0], $MachinePrecision]
                    
                    \begin{array}{l}
                    
                    \\
                    {N}^{-1}
                    \end{array}
                    
                    Derivation
                    1. Initial program 21.9%

                      \[\log \left(N + 1\right) - \log N \]
                    2. Add Preprocessing
                    3. Taylor expanded in N around inf

                      \[\leadsto \color{blue}{\frac{1}{N}} \]
                    4. Step-by-step derivation
                      1. lower-/.f6486.0

                        \[\leadsto \color{blue}{\frac{1}{N}} \]
                    5. Applied rewrites86.0%

                      \[\leadsto \color{blue}{\frac{1}{N}} \]
                    6. Final simplification86.0%

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

                    Alternative 8: 96.4% accurate, 4.1× speedup?

                    \[\begin{array}{l} \\ \frac{\frac{-0.5 - \frac{\mathsf{fma}\left(-0.3333333333333333, N, 0.25\right)}{N \cdot N}}{N} - -1}{N} \end{array} \]
                    (FPCore (N)
                     :precision binary64
                     (/ (- (/ (- -0.5 (/ (fma -0.3333333333333333 N 0.25) (* N N))) N) -1.0) N))
                    double code(double N) {
                    	return (((-0.5 - (fma(-0.3333333333333333, N, 0.25) / (N * N))) / N) - -1.0) / N;
                    }
                    
                    function code(N)
                    	return Float64(Float64(Float64(Float64(-0.5 - Float64(fma(-0.3333333333333333, N, 0.25) / Float64(N * N))) / N) - -1.0) / N)
                    end
                    
                    code[N_] := N[(N[(N[(N[(-0.5 - N[(N[(-0.3333333333333333 * N + 0.25), $MachinePrecision] / N[(N * N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N), $MachinePrecision] - -1.0), $MachinePrecision] / N), $MachinePrecision]
                    
                    \begin{array}{l}
                    
                    \\
                    \frac{\frac{-0.5 - \frac{\mathsf{fma}\left(-0.3333333333333333, N, 0.25\right)}{N \cdot N}}{N} - -1}{N}
                    \end{array}
                    
                    Derivation
                    1. Initial program 21.9%

                      \[\log \left(N + 1\right) - \log N \]
                    2. Add Preprocessing
                    3. Taylor expanded in N around inf

                      \[\leadsto \color{blue}{\frac{\left(1 + \frac{\frac{1}{3}}{{N}^{2}}\right) - \left(\frac{1}{2} \cdot \frac{1}{N} + \frac{1}{4} \cdot \frac{1}{{N}^{3}}\right)}{N}} \]
                    4. Applied rewrites97.5%

                      \[\leadsto \color{blue}{\frac{\frac{-0.5 - \frac{\frac{0.25}{N} - 0.3333333333333333}{N}}{N} - -1}{N}} \]
                    5. Taylor expanded in N around 0

                      \[\leadsto \frac{\frac{\frac{-1}{2} - \frac{\frac{1}{4} + \frac{-1}{3} \cdot N}{{N}^{2}}}{N} - -1}{N} \]
                    6. Step-by-step derivation
                      1. Applied rewrites97.5%

                        \[\leadsto \frac{\frac{-0.5 - \frac{\mathsf{fma}\left(-0.3333333333333333, N, 0.25\right)}{N \cdot N}}{N} - -1}{N} \]
                      2. Add Preprocessing

                      Alternative 9: 95.0% accurate, 5.2× speedup?

                      \[\begin{array}{l} \\ \frac{\frac{\frac{0.3333333333333333}{N} - 0.5}{N} - -1}{N} \end{array} \]
                      (FPCore (N)
                       :precision binary64
                       (/ (- (/ (- (/ 0.3333333333333333 N) 0.5) N) -1.0) N))
                      double code(double N) {
                      	return ((((0.3333333333333333 / N) - 0.5) / N) - -1.0) / N;
                      }
                      
                      real(8) function code(n)
                          real(8), intent (in) :: n
                          code = ((((0.3333333333333333d0 / n) - 0.5d0) / n) - (-1.0d0)) / n
                      end function
                      
                      public static double code(double N) {
                      	return ((((0.3333333333333333 / N) - 0.5) / N) - -1.0) / N;
                      }
                      
                      def code(N):
                      	return ((((0.3333333333333333 / N) - 0.5) / N) - -1.0) / N
                      
                      function code(N)
                      	return Float64(Float64(Float64(Float64(Float64(0.3333333333333333 / N) - 0.5) / N) - -1.0) / N)
                      end
                      
                      function tmp = code(N)
                      	tmp = ((((0.3333333333333333 / N) - 0.5) / N) - -1.0) / N;
                      end
                      
                      code[N_] := N[(N[(N[(N[(N[(0.3333333333333333 / N), $MachinePrecision] - 0.5), $MachinePrecision] / N), $MachinePrecision] - -1.0), $MachinePrecision] / N), $MachinePrecision]
                      
                      \begin{array}{l}
                      
                      \\
                      \frac{\frac{\frac{0.3333333333333333}{N} - 0.5}{N} - -1}{N}
                      \end{array}
                      
                      Derivation
                      1. Initial program 21.9%

                        \[\log \left(N + 1\right) - \log N \]
                      2. Add Preprocessing
                      3. Taylor expanded in N around inf

                        \[\leadsto \color{blue}{\frac{\left(1 + \frac{\frac{1}{3}}{{N}^{2}}\right) - \frac{1}{2} \cdot \frac{1}{N}}{N}} \]
                      4. Step-by-step derivation
                        1. lower-/.f64N/A

                          \[\leadsto \color{blue}{\frac{\left(1 + \frac{\frac{1}{3}}{{N}^{2}}\right) - \frac{1}{2} \cdot \frac{1}{N}}{N}} \]
                      5. Applied rewrites96.2%

                        \[\leadsto \color{blue}{\frac{\frac{\frac{0.3333333333333333}{N} - 0.5}{N} - -1}{N}} \]
                      6. Add Preprocessing

                      Alternative 10: 92.3% accurate, 8.0× speedup?

                      \[\begin{array}{l} \\ \frac{1 - \frac{0.5}{N}}{N} \end{array} \]
                      (FPCore (N) :precision binary64 (/ (- 1.0 (/ 0.5 N)) N))
                      double code(double N) {
                      	return (1.0 - (0.5 / N)) / N;
                      }
                      
                      real(8) function code(n)
                          real(8), intent (in) :: n
                          code = (1.0d0 - (0.5d0 / n)) / n
                      end function
                      
                      public static double code(double N) {
                      	return (1.0 - (0.5 / N)) / N;
                      }
                      
                      def code(N):
                      	return (1.0 - (0.5 / N)) / N
                      
                      function code(N)
                      	return Float64(Float64(1.0 - Float64(0.5 / N)) / N)
                      end
                      
                      function tmp = code(N)
                      	tmp = (1.0 - (0.5 / N)) / N;
                      end
                      
                      code[N_] := N[(N[(1.0 - N[(0.5 / N), $MachinePrecision]), $MachinePrecision] / N), $MachinePrecision]
                      
                      \begin{array}{l}
                      
                      \\
                      \frac{1 - \frac{0.5}{N}}{N}
                      \end{array}
                      
                      Derivation
                      1. Initial program 21.9%

                        \[\log \left(N + 1\right) - \log N \]
                      2. Add Preprocessing
                      3. Taylor expanded in N around inf

                        \[\leadsto \color{blue}{\frac{1 - \frac{1}{2} \cdot \frac{1}{N}}{N}} \]
                      4. Step-by-step derivation
                        1. lower-/.f64N/A

                          \[\leadsto \color{blue}{\frac{1 - \frac{1}{2} \cdot \frac{1}{N}}{N}} \]
                        2. lower--.f64N/A

                          \[\leadsto \frac{\color{blue}{1 - \frac{1}{2} \cdot \frac{1}{N}}}{N} \]
                        3. associate-*r/N/A

                          \[\leadsto \frac{1 - \color{blue}{\frac{\frac{1}{2} \cdot 1}{N}}}{N} \]
                        4. metadata-evalN/A

                          \[\leadsto \frac{1 - \frac{\color{blue}{\frac{1}{2}}}{N}}{N} \]
                        5. lower-/.f6493.4

                          \[\leadsto \frac{1 - \color{blue}{\frac{0.5}{N}}}{N} \]
                      5. Applied rewrites93.4%

                        \[\leadsto \color{blue}{\frac{1 - \frac{0.5}{N}}{N}} \]
                      6. Add Preprocessing

                      Alternative 11: 3.3% accurate, 207.0× speedup?

                      \[\begin{array}{l} \\ 0 \end{array} \]
                      (FPCore (N) :precision binary64 0.0)
                      double code(double N) {
                      	return 0.0;
                      }
                      
                      real(8) function code(n)
                          real(8), intent (in) :: n
                          code = 0.0d0
                      end function
                      
                      public static double code(double N) {
                      	return 0.0;
                      }
                      
                      def code(N):
                      	return 0.0
                      
                      function code(N)
                      	return 0.0
                      end
                      
                      function tmp = code(N)
                      	tmp = 0.0;
                      end
                      
                      code[N_] := 0.0
                      
                      \begin{array}{l}
                      
                      \\
                      0
                      \end{array}
                      
                      Derivation
                      1. Initial program 21.9%

                        \[\log \left(N + 1\right) - \log N \]
                      2. Add Preprocessing
                      3. Step-by-step derivation
                        1. lift--.f64N/A

                          \[\leadsto \color{blue}{\log \left(N + 1\right) - \log N} \]
                        2. flip--N/A

                          \[\leadsto \color{blue}{\frac{\log \left(N + 1\right) \cdot \log \left(N + 1\right) - \log N \cdot \log N}{\log \left(N + 1\right) + \log N}} \]
                        3. lower-/.f64N/A

                          \[\leadsto \color{blue}{\frac{\log \left(N + 1\right) \cdot \log \left(N + 1\right) - \log N \cdot \log N}{\log \left(N + 1\right) + \log N}} \]
                        4. lower--.f64N/A

                          \[\leadsto \frac{\color{blue}{\log \left(N + 1\right) \cdot \log \left(N + 1\right) - \log N \cdot \log N}}{\log \left(N + 1\right) + \log N} \]
                        5. pow2N/A

                          \[\leadsto \frac{\color{blue}{{\log \left(N + 1\right)}^{2}} - \log N \cdot \log N}{\log \left(N + 1\right) + \log N} \]
                        6. lower-pow.f64N/A

                          \[\leadsto \frac{\color{blue}{{\log \left(N + 1\right)}^{2}} - \log N \cdot \log N}{\log \left(N + 1\right) + \log N} \]
                        7. lift-log.f64N/A

                          \[\leadsto \frac{{\color{blue}{\log \left(N + 1\right)}}^{2} - \log N \cdot \log N}{\log \left(N + 1\right) + \log N} \]
                        8. lift-+.f64N/A

                          \[\leadsto \frac{{\log \color{blue}{\left(N + 1\right)}}^{2} - \log N \cdot \log N}{\log \left(N + 1\right) + \log N} \]
                        9. +-commutativeN/A

                          \[\leadsto \frac{{\log \color{blue}{\left(1 + N\right)}}^{2} - \log N \cdot \log N}{\log \left(N + 1\right) + \log N} \]
                        10. lower-log1p.f64N/A

                          \[\leadsto \frac{{\color{blue}{\left(\mathsf{log1p}\left(N\right)\right)}}^{2} - \log N \cdot \log N}{\log \left(N + 1\right) + \log N} \]
                        11. pow2N/A

                          \[\leadsto \frac{{\left(\mathsf{log1p}\left(N\right)\right)}^{2} - \color{blue}{{\log N}^{2}}}{\log \left(N + 1\right) + \log N} \]
                        12. lower-pow.f64N/A

                          \[\leadsto \frac{{\left(\mathsf{log1p}\left(N\right)\right)}^{2} - \color{blue}{{\log N}^{2}}}{\log \left(N + 1\right) + \log N} \]
                        13. +-commutativeN/A

                          \[\leadsto \frac{{\left(\mathsf{log1p}\left(N\right)\right)}^{2} - {\log N}^{2}}{\color{blue}{\log N + \log \left(N + 1\right)}} \]
                        14. lower-+.f6421.8

                          \[\leadsto \frac{{\left(\mathsf{log1p}\left(N\right)\right)}^{2} - {\log N}^{2}}{\color{blue}{\log N + \log \left(N + 1\right)}} \]
                        15. lift-log.f64N/A

                          \[\leadsto \frac{{\left(\mathsf{log1p}\left(N\right)\right)}^{2} - {\log N}^{2}}{\log N + \color{blue}{\log \left(N + 1\right)}} \]
                        16. lift-+.f64N/A

                          \[\leadsto \frac{{\left(\mathsf{log1p}\left(N\right)\right)}^{2} - {\log N}^{2}}{\log N + \log \color{blue}{\left(N + 1\right)}} \]
                        17. +-commutativeN/A

                          \[\leadsto \frac{{\left(\mathsf{log1p}\left(N\right)\right)}^{2} - {\log N}^{2}}{\log N + \log \color{blue}{\left(1 + N\right)}} \]
                        18. lower-log1p.f6421.8

                          \[\leadsto \frac{{\left(\mathsf{log1p}\left(N\right)\right)}^{2} - {\log N}^{2}}{\log N + \color{blue}{\mathsf{log1p}\left(N\right)}} \]
                      4. Applied rewrites21.8%

                        \[\leadsto \color{blue}{\frac{{\left(\mathsf{log1p}\left(N\right)\right)}^{2} - {\log N}^{2}}{\log N + \mathsf{log1p}\left(N\right)}} \]
                      5. Step-by-step derivation
                        1. lift--.f64N/A

                          \[\leadsto \frac{\color{blue}{{\left(\mathsf{log1p}\left(N\right)\right)}^{2} - {\log N}^{2}}}{\log N + \mathsf{log1p}\left(N\right)} \]
                        2. sub-negN/A

                          \[\leadsto \frac{\color{blue}{{\left(\mathsf{log1p}\left(N\right)\right)}^{2} + \left(\mathsf{neg}\left({\log N}^{2}\right)\right)}}{\log N + \mathsf{log1p}\left(N\right)} \]
                        3. lift-neg.f64N/A

                          \[\leadsto \frac{{\left(\mathsf{log1p}\left(N\right)\right)}^{2} + \color{blue}{\left(-{\log N}^{2}\right)}}{\log N + \mathsf{log1p}\left(N\right)} \]
                        4. +-commutativeN/A

                          \[\leadsto \frac{\color{blue}{\left(-{\log N}^{2}\right) + {\left(\mathsf{log1p}\left(N\right)\right)}^{2}}}{\log N + \mathsf{log1p}\left(N\right)} \]
                        5. lift-neg.f64N/A

                          \[\leadsto \frac{\color{blue}{\left(\mathsf{neg}\left({\log N}^{2}\right)\right)} + {\left(\mathsf{log1p}\left(N\right)\right)}^{2}}{\log N + \mathsf{log1p}\left(N\right)} \]
                        6. lift-pow.f64N/A

                          \[\leadsto \frac{\left(\mathsf{neg}\left(\color{blue}{{\log N}^{2}}\right)\right) + {\left(\mathsf{log1p}\left(N\right)\right)}^{2}}{\log N + \mathsf{log1p}\left(N\right)} \]
                        7. unpow2N/A

                          \[\leadsto \frac{\left(\mathsf{neg}\left(\color{blue}{\log N \cdot \log N}\right)\right) + {\left(\mathsf{log1p}\left(N\right)\right)}^{2}}{\log N + \mathsf{log1p}\left(N\right)} \]
                        8. distribute-lft-neg-inN/A

                          \[\leadsto \frac{\color{blue}{\left(\mathsf{neg}\left(\log N\right)\right) \cdot \log N} + {\left(\mathsf{log1p}\left(N\right)\right)}^{2}}{\log N + \mathsf{log1p}\left(N\right)} \]
                        9. lower-fma.f64N/A

                          \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\mathsf{neg}\left(\log N\right), \log N, {\left(\mathsf{log1p}\left(N\right)\right)}^{2}\right)}}{\log N + \mathsf{log1p}\left(N\right)} \]
                        10. lower-neg.f6423.9

                          \[\leadsto \frac{\mathsf{fma}\left(\color{blue}{-\log N}, \log N, {\left(\mathsf{log1p}\left(N\right)\right)}^{2}\right)}{\log N + \mathsf{log1p}\left(N\right)} \]
                      6. Applied rewrites23.9%

                        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(-\log N, \log N, {\left(\mathsf{log1p}\left(N\right)\right)}^{2}\right)}}{\log N + \mathsf{log1p}\left(N\right)} \]
                      7. Taylor expanded in N around -inf

                        \[\leadsto \color{blue}{\frac{-1 \cdot {\left(\log -1 + -1 \cdot \log \left(\frac{-1}{N}\right)\right)}^{2} + {\left(\log -1 + -1 \cdot \log \left(\frac{-1}{N}\right)\right)}^{2}}{-2 \cdot \log \left(\frac{-1}{N}\right) + 2 \cdot \log -1}} \]
                      8. Step-by-step derivation
                        1. distribute-lft1-inN/A

                          \[\leadsto \frac{\color{blue}{\left(-1 + 1\right) \cdot {\left(\log -1 + -1 \cdot \log \left(\frac{-1}{N}\right)\right)}^{2}}}{-2 \cdot \log \left(\frac{-1}{N}\right) + 2 \cdot \log -1} \]
                        2. metadata-evalN/A

                          \[\leadsto \frac{\color{blue}{0} \cdot {\left(\log -1 + -1 \cdot \log \left(\frac{-1}{N}\right)\right)}^{2}}{-2 \cdot \log \left(\frac{-1}{N}\right) + 2 \cdot \log -1} \]
                        3. associate-*r/N/A

                          \[\leadsto \color{blue}{0 \cdot \frac{{\left(\log -1 + -1 \cdot \log \left(\frac{-1}{N}\right)\right)}^{2}}{-2 \cdot \log \left(\frac{-1}{N}\right) + 2 \cdot \log -1}} \]
                        4. mul0-lft3.3

                          \[\leadsto \color{blue}{0} \]
                      9. Applied rewrites3.3%

                        \[\leadsto \color{blue}{0} \]
                      10. Final simplification3.3%

                        \[\leadsto 0 \]
                      11. Add Preprocessing

                      Developer Target 1: 96.3% accurate, 0.6× speedup?

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

                      Reproduce

                      ?
                      herbie shell --seed 2024324 
                      (FPCore (N)
                        :name "2log (problem 3.3.6)"
                        :precision binary64
                        :pre (and (> N 1.0) (< N 1e+40))
                      
                        :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)))