Average Error: 10.0 → 0.1
Time: 1.2m
Precision: 64
Internal Precision: 1088
\[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1}\]
\[\frac{\frac{2}{x}}{-1 + x \cdot x}\]

Error

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Your Program's Arguments

Results

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Target

Original10.0
Target0.3
Herbie0.1
\[\frac{2}{x \cdot \left(x \cdot x - 1\right)}\]

Derivation

  1. Initial program 10.0

    \[\left(\frac{1}{x + 1} - \frac{2}{x}\right) + \frac{1}{x - 1}\]
  2. Using strategy rm
  3. Applied frac-sub25.8

    \[\leadsto \color{blue}{\frac{1 \cdot x - \left(x + 1\right) \cdot 2}{\left(x + 1\right) \cdot x}} + \frac{1}{x - 1}\]
  4. Applied frac-add25.1

    \[\leadsto \color{blue}{\frac{\left(1 \cdot x - \left(x + 1\right) \cdot 2\right) \cdot \left(x - 1\right) + \left(\left(x + 1\right) \cdot x\right) \cdot 1}{\left(\left(x + 1\right) \cdot x\right) \cdot \left(x - 1\right)}}\]
  5. Taylor expanded around 0 0.3

    \[\leadsto \frac{\color{blue}{2}}{\left(\left(x + 1\right) \cdot x\right) \cdot \left(x - 1\right)}\]
  6. Using strategy rm
  7. Applied associate-/r*0.1

    \[\leadsto \color{blue}{\frac{\frac{2}{\left(x + 1\right) \cdot x}}{x - 1}}\]
  8. Using strategy rm
  9. Applied *-un-lft-identity0.1

    \[\leadsto \frac{\frac{2}{\left(x + 1\right) \cdot x}}{\color{blue}{1 \cdot \left(x - 1\right)}}\]
  10. Applied flip-+0.1

    \[\leadsto \frac{\frac{2}{\color{blue}{\frac{x \cdot x - 1 \cdot 1}{x - 1}} \cdot x}}{1 \cdot \left(x - 1\right)}\]
  11. Applied associate-*l/0.3

    \[\leadsto \frac{\frac{2}{\color{blue}{\frac{\left(x \cdot x - 1 \cdot 1\right) \cdot x}{x - 1}}}}{1 \cdot \left(x - 1\right)}\]
  12. Applied associate-/r/0.3

    \[\leadsto \frac{\color{blue}{\frac{2}{\left(x \cdot x - 1 \cdot 1\right) \cdot x} \cdot \left(x - 1\right)}}{1 \cdot \left(x - 1\right)}\]
  13. Applied times-frac0.3

    \[\leadsto \color{blue}{\frac{\frac{2}{\left(x \cdot x - 1 \cdot 1\right) \cdot x}}{1} \cdot \frac{x - 1}{x - 1}}\]
  14. Simplified0.1

    \[\leadsto \color{blue}{\frac{\frac{2}{x}}{-1 + x \cdot x}} \cdot \frac{x - 1}{x - 1}\]
  15. Simplified0.1

    \[\leadsto \frac{\frac{2}{x}}{-1 + x \cdot x} \cdot \color{blue}{1}\]
  16. Final simplification0.1

    \[\leadsto \frac{\frac{2}{x}}{-1 + x \cdot x}\]

Runtime

Time bar (total: 1.2m)Debug logProfile

herbie shell --seed 2018255 
(FPCore (x)
  :name "3frac (problem 3.3.3)"

  :herbie-target
  (/ 2 (* x (- (* x x) 1)))

  (+ (- (/ 1 (+ x 1)) (/ 2 x)) (/ 1 (- x 1))))