Average Error: 14.3 → 0.1
Time: 9.1s
Precision: 64
Ground Truth: 128
\[\frac{1}{x + 1} - \frac{1}{x}\]
\[\frac{\frac{-1}{x}}{x + 1}\]

Error

Bits error versus x

Derivation

  1. Initial program 14.3

    \[\frac{1}{x + 1} - \frac{1}{x}\]
  2. Using strategy rm
  3. Applied frac-sub 13.7

    \[\leadsto \color{blue}{\frac{1 \cdot x - \left(x + 1\right) \cdot 1}{\left(x + 1\right) \cdot x}}\]
  4. Applied simplify 13.7

    \[\leadsto \frac{\color{blue}{x - \left(1 + x\right)}}{\left(x + 1\right) \cdot x}\]
  5. Using strategy rm
  6. Applied add-cube-cbrt 14.4

    \[\leadsto \frac{x - \left(1 + x\right)}{\color{blue}{{\left(\sqrt[3]{\left(x + 1\right) \cdot x}\right)}^3}}\]
  7. Applied add-cube-cbrt 14.4

    \[\leadsto \frac{\color{blue}{{\left(\sqrt[3]{x - \left(1 + x\right)}\right)}^3}}{{\left(\sqrt[3]{\left(x + 1\right) \cdot x}\right)}^3}\]
  8. Applied cube-undiv 14.5

    \[\leadsto \color{blue}{{\left(\frac{\sqrt[3]{x - \left(1 + x\right)}}{\sqrt[3]{\left(x + 1\right) \cdot x}}\right)}^3}\]
  9. Applied taylor 1.4

    \[\leadsto {\left(\frac{\sqrt[3]{-1}}{\sqrt[3]{\left(x + 1\right) \cdot x}}\right)}^3\]
  10. Taylor expanded around 0 1.4

    \[\leadsto {\left(\frac{\sqrt[3]{\color{blue}{-1}}}{\sqrt[3]{\left(x + 1\right) \cdot x}}\right)}^3\]
  11. Applied simplify 0.1

    \[\leadsto \color{blue}{\frac{\frac{-1}{x}}{x + 1}}\]
  12. Removed slow pow expressions

Runtime

Total time: 9.1s Debug log

Please report a bug with the following info:

herbie --seed '#(420001148 2394011633 3690194946 4245530932 3600965098 1065492769)'
(FPCore (x)
  :name "NMSE problem 3.3.1"
  (- (/ 1 (+ x 1)) (/ 1 x)))