Average Error: 10.6 → 0.3
Time: 5.4s
Precision: binary64
\[x + \frac{y \cdot \left(z - t\right)}{z - a}\]
\[\begin{array}{l} \mathbf{if}\;\frac{y \cdot \left(z - t\right)}{z - a} = -inf.0:\\ \;\;\;\;x + y \cdot \frac{z - t}{z - a}\\ \mathbf{elif}\;\frac{y \cdot \left(z - t\right)}{z - a} \le 2.1327535190838117 \cdot 10^{286}:\\ \;\;\;\;x + \frac{y \cdot z + y \cdot \left(-t\right)}{z - a}\\ \mathbf{else}:\\ \;\;\;\;x + \frac{\frac{y}{z - a}}{\frac{1}{z - t}}\\ \end{array}\]

Error

Bits error versus x

Bits error versus y

Bits error versus z

Bits error versus t

Bits error versus a

Target

Original10.6
Target1.2
Herbie0.3
\[x + \frac{y}{\frac{z - a}{z - t}}\]

Derivation

  1. Split input into 3 regimes
  2. if (/ (* y (- z t)) (- z a)) < -inf.0

    1. Initial program 64.0

      \[x + \frac{y \cdot \left(z - t\right)}{z - a}\]
    2. Using strategy rm
    3. Applied *-un-lft-identity64.0

      \[\leadsto x + \frac{y \cdot \left(z - t\right)}{\color{blue}{1 \cdot \left(z - a\right)}}\]
    4. Applied times-frac0.1

      \[\leadsto x + \color{blue}{\frac{y}{1} \cdot \frac{z - t}{z - a}}\]
    5. Simplified0.1

      \[\leadsto x + \color{blue}{y} \cdot \frac{z - t}{z - a}\]

    if -inf.0 < (/ (* y (- z t)) (- z a)) < 2.1327535190838117e286

    1. Initial program 0.2

      \[x + \frac{y \cdot \left(z - t\right)}{z - a}\]
    2. Using strategy rm
    3. Applied sub-neg0.2

      \[\leadsto x + \frac{y \cdot \color{blue}{\left(z + \left(-t\right)\right)}}{z - a}\]
    4. Applied distribute-lft-in0.2

      \[\leadsto x + \frac{\color{blue}{y \cdot z + y \cdot \left(-t\right)}}{z - a}\]

    if 2.1327535190838117e286 < (/ (* y (- z t)) (- z a))

    1. Initial program 60.5

      \[x + \frac{y \cdot \left(z - t\right)}{z - a}\]
    2. Using strategy rm
    3. Applied associate-/l*0.6

      \[\leadsto x + \color{blue}{\frac{y}{\frac{z - a}{z - t}}}\]
    4. Using strategy rm
    5. Applied div-inv0.7

      \[\leadsto x + \frac{y}{\color{blue}{\left(z - a\right) \cdot \frac{1}{z - t}}}\]
    6. Applied associate-/r*1.2

      \[\leadsto x + \color{blue}{\frac{\frac{y}{z - a}}{\frac{1}{z - t}}}\]
  3. Recombined 3 regimes into one program.
  4. Final simplification0.3

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{y \cdot \left(z - t\right)}{z - a} = -inf.0:\\ \;\;\;\;x + y \cdot \frac{z - t}{z - a}\\ \mathbf{elif}\;\frac{y \cdot \left(z - t\right)}{z - a} \le 2.1327535190838117 \cdot 10^{286}:\\ \;\;\;\;x + \frac{y \cdot z + y \cdot \left(-t\right)}{z - a}\\ \mathbf{else}:\\ \;\;\;\;x + \frac{\frac{y}{z - a}}{\frac{1}{z - t}}\\ \end{array}\]

Reproduce

herbie shell --seed 2020174 
(FPCore (x y z t a)
  :name "Graphics.Rendering.Plot.Render.Plot.Axis:renderAxisTicks from plot-0.2.3.4, A"
  :precision binary64

  :herbie-target
  (+ x (/ y (/ (- z a) (- z t))))

  (+ x (/ (* y (- z t)) (- z a))))