Average Error: 3.6 → 3.1
Time: 16.4s
Precision: 64
Internal Precision: 128
\[\left(a + \left(b + \left(c + d\right)\right)\right) \cdot 2\]
\[2 \cdot (e^{\log_* (1 + \sqrt[3]{\left(\left(\left(b + c\right) + a\right) + d\right) \cdot \left(\left(\left(\left(b + c\right) + d\right) + a\right) \cdot \left(\left(\left(b + c\right) + d\right) + a\right)\right)})} - 1)^*\]

Error

Bits error versus a

Bits error versus b

Bits error versus c

Bits error versus d

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original3.6
Target3.9
Herbie3.1
\[\left(a + b\right) \cdot 2 + \left(c + d\right) \cdot 2\]

Derivation

  1. Initial program 3.6

    \[\left(a + \left(b + \left(c + d\right)\right)\right) \cdot 2\]
  2. Using strategy rm
  3. Applied associate-+r+2.8

    \[\leadsto \left(a + \color{blue}{\left(\left(b + c\right) + d\right)}\right) \cdot 2\]
  4. Using strategy rm
  5. Applied expm1-log1p-u3.1

    \[\leadsto \color{blue}{(e^{\log_* (1 + \left(a + \left(\left(b + c\right) + d\right)\right))} - 1)^*} \cdot 2\]
  6. Using strategy rm
  7. Applied add-cbrt-cube3.2

    \[\leadsto (e^{\log_* (1 + \color{blue}{\sqrt[3]{\left(\left(a + \left(\left(b + c\right) + d\right)\right) \cdot \left(a + \left(\left(b + c\right) + d\right)\right)\right) \cdot \left(a + \left(\left(b + c\right) + d\right)\right)}})} - 1)^* \cdot 2\]
  8. Using strategy rm
  9. Applied associate-+r+3.1

    \[\leadsto (e^{\log_* (1 + \sqrt[3]{\left(\left(a + \left(\left(b + c\right) + d\right)\right) \cdot \left(a + \left(\left(b + c\right) + d\right)\right)\right) \cdot \color{blue}{\left(\left(a + \left(b + c\right)\right) + d\right)}})} - 1)^* \cdot 2\]
  10. Final simplification3.1

    \[\leadsto 2 \cdot (e^{\log_* (1 + \sqrt[3]{\left(\left(\left(b + c\right) + a\right) + d\right) \cdot \left(\left(\left(\left(b + c\right) + d\right) + a\right) \cdot \left(\left(\left(b + c\right) + d\right) + a\right)\right)})} - 1)^*\]

Reproduce

herbie shell --seed 2019026 +o rules:numerics
(FPCore (a b c d)
  :name "Expression, p6"
  :pre (and (<= -14 a -13) (<= -3 b -2) (<= 3 c 3.5) (<= 12.5 d 13.5))

  :herbie-target
  (+ (* (+ a b) 2) (* (+ c d) 2))

  (* (+ a (+ b (+ c d))) 2))