Error

Derivation

1. Initial program 1.5

   \[\left(\frac{1}{\sqrt{\pi}} \cdot e^{\left|x\right| \cdot \left|x\right|}\right) \cdot \left(\left(\left(\frac{1}{\left|x\right|} + \frac{1}{2} \cdot \left(\left(\frac{1}{\left|x\right|} \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right)\right) + \frac{3}{4} \cdot \left(\left(\left(\left(\frac{1}{\left|x\right|} \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right)\right) + \frac{15}{8} \cdot \left(\left(\left(\left(\left(\left(\frac{1}{\left|x\right|} \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right)\right)\]

2. Initial simplification1.4

   \[\leadsto (\left(\frac{e^{\left|x\right| \cdot \left|x\right|}}{\sqrt{\pi}}\right) \cdot \left((\left({\left(\frac{1}{\left|x\right|}\right)}^{4} \cdot \frac{3}{4}\right) \cdot \left(\frac{1}{\left|x\right|}\right) + \left((\left({\left(\frac{1}{\left|x\right|}\right)}^{3}\right) \cdot \frac{1}{2} + \left(\frac{1}{\left|x\right|}\right))_*\right))_*\right) + \left(\left({\left(\frac{1}{\left|x\right|}\right)}^{3} \cdot {\left(\frac{1}{\left|x\right|}\right)}^{4}\right) \cdot \left(\left(\frac{15}{8} \cdot \frac{1}{\sqrt{\pi}}\right) \cdot e^{\left|x\right| \cdot \left|x\right|}\right)\right))_*\]
3. Using strategy rm

4. Applied inv-pow1.4

   \[\leadsto (\left(\frac{e^{\left|x\right| \cdot \left|x\right|}}{\sqrt{\pi}}\right) \cdot \left((\left({\left(\frac{1}{\left|x\right|}\right)}^{4} \cdot \frac{3}{4}\right) \cdot \left(\frac{1}{\left|x\right|}\right) + \left((\left({\left(\frac{1}{\left|x\right|}\right)}^{3}\right) \cdot \frac{1}{2} + \left(\frac{1}{\left|x\right|}\right))_*\right))_*\right) + \left(\left({\left(\frac{1}{\left|x\right|}\right)}^{3} \cdot {\color{blue}{\left({\left(\left|x\right|\right)}^{-1}\right)}}^{4}\right) \cdot \left(\left(\frac{15}{8} \cdot \frac{1}{\sqrt{\pi}}\right) \cdot e^{\left|x\right| \cdot \left|x\right|}\right)\right))_*\]

5. Applied pow-pow0.9

   \[\leadsto (\left(\frac{e^{\left|x\right| \cdot \left|x\right|}}{\sqrt{\pi}}\right) \cdot \left((\left({\left(\frac{1}{\left|x\right|}\right)}^{4} \cdot \frac{3}{4}\right) \cdot \left(\frac{1}{\left|x\right|}\right) + \left((\left({\left(\frac{1}{\left|x\right|}\right)}^{3}\right) \cdot \frac{1}{2} + \left(\frac{1}{\left|x\right|}\right))_*\right))_*\right) + \left(\left({\left(\frac{1}{\left|x\right|}\right)}^{3} \cdot \color{blue}{{\left(\left|x\right|\right)}^{\left(-1 \cdot 4\right)}}\right) \cdot \left(\left(\frac{15}{8} \cdot \frac{1}{\sqrt{\pi}}\right) \cdot e^{\left|x\right| \cdot \left|x\right|}\right)\right))_*\]
6. Using strategy rm

7. Applied inv-pow0.9

   \[\leadsto (\left(\frac{e^{\left|x\right| \cdot \left|x\right|}}{\sqrt{\pi}}\right) \cdot \left((\left({\left(\frac{1}{\left|x\right|}\right)}^{4} \cdot \frac{3}{4}\right) \cdot \left(\frac{1}{\left|x\right|}\right) + \left((\left({\left(\frac{1}{\left|x\right|}\right)}^{3}\right) \cdot \frac{1}{2} + \left(\frac{1}{\left|x\right|}\right))_*\right))_*\right) + \left(\left({\color{blue}{\left({\left(\left|x\right|\right)}^{-1}\right)}}^{3} \cdot {\left(\left|x\right|\right)}^{\left(-1 \cdot 4\right)}\right) \cdot \left(\left(\frac{15}{8} \cdot \frac{1}{\sqrt{\pi}}\right) \cdot e^{\left|x\right| \cdot \left|x\right|}\right)\right))_*\]

8. Applied pow-pow0.6

   \[\leadsto (\left(\frac{e^{\left|x\right| \cdot \left|x\right|}}{\sqrt{\pi}}\right) \cdot \left((\left({\left(\frac{1}{\left|x\right|}\right)}^{4} \cdot \frac{3}{4}\right) \cdot \left(\frac{1}{\left|x\right|}\right) + \left((\left({\left(\frac{1}{\left|x\right|}\right)}^{3}\right) \cdot \frac{1}{2} + \left(\frac{1}{\left|x\right|}\right))_*\right))_*\right) + \left(\left(\color{blue}{{\left(\left|x\right|\right)}^{\left(-1 \cdot 3\right)}} \cdot {\left(\left|x\right|\right)}^{\left(-1 \cdot 4\right)}\right) \cdot \left(\left(\frac{15}{8} \cdot \frac{1}{\sqrt{\pi}}\right) \cdot e^{\left|x\right| \cdot \left|x\right|}\right)\right))_*\]

9. Final simplification0.6

   \[\leadsto (\left(\frac{e^{\left|x\right| \cdot \left|x\right|}}{\sqrt{\pi}}\right) \cdot \left((\left({\left(\frac{1}{\left|x\right|}\right)}^{4} \cdot \frac{3}{4}\right) \cdot \left(\frac{1}{\left|x\right|}\right) + \left((\left({\left(\frac{1}{\left|x\right|}\right)}^{3}\right) \cdot \frac{1}{2} + \left(\frac{1}{\left|x\right|}\right))_*\right))_*\right) + \left(\left(e^{\left|x\right| \cdot \left|x\right|} \cdot \left(\frac{15}{8} \cdot \frac{1}{\sqrt{\pi}}\right)\right) \cdot \left({\left(\left|x\right|\right)}^{-4} \cdot {\left(\left|x\right|\right)}^{-3}\right)\right))_*\]

Reproduce

herbie shell --seed 2018360 +o rules:numerics
(FPCore (x)
  :name "Jmat.Real.erfi, branch x greater than or equal to 5"
  (* (* (/ 1 (sqrt PI)) (exp (* (fabs x) (fabs x)))) (+ (+ (+ (/ 1 (fabs x)) (* (/ 1 2) (* (* (/ 1 (fabs x)) (/ 1 (fabs x))) (/ 1 (fabs x))))) (* (/ 3 4) (* (* (* (* (/ 1 (fabs x)) (/ 1 (fabs x))) (/ 1 (fabs x))) (/ 1 (fabs x))) (/ 1 (fabs x))))) (* (/ 15 8) (* (* (* (* (* (* (/ 1 (fabs x)) (/ 1 (fabs x))) (/ 1 (fabs x))) (/ 1 (fabs x))) (/ 1 (fabs x))) (/ 1 (fabs x))) (/ 1 (fabs x)))))))

Details

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