Average Error: 3.7 → 0
Time: 2.8s
Precision: 64
\[-14 \le a \le -13 \land -3 \le b \le -2 \land 3 \le c \le 3.5 \land 12.5 \le d \le 13.5\]
\[\left(a + \left(b + \left(c + d\right)\right)\right) \cdot 2\]
↓
\[\left(\left(a + d\right) + \left(b + c\right)\right) \cdot 2\]
\left(a + \left(b + \left(c + d\right)\right)\right) \cdot 2
↓
\left(\left(a + d\right) + \left(b + c\right)\right) \cdot 2
double f(double a, double b, double c, double d) {
        double r66531 = a;
        double r66532 = b;
        double r66533 = c;
        double r66534 = d;
        double r66535 = r66533 + r66534;
        double r66536 = r66532 + r66535;
        double r66537 = r66531 + r66536;
        double r66538 = 2.0;
        double r66539 = r66537 * r66538;
        return r66539;
}
↓
double f(double a, double b, double c, double d) {
        double r66540 = a;
        double r66541 = d;
        double r66542 = r66540 + r66541;
        double r66543 = b;
        double r66544 = c;
        double r66545 = r66543 + r66544;
        double r66546 = r66542 + r66545;
        double r66547 = 2.0;
        double r66548 = r66546 * r66547;
        return r66548;
}

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

Original3.7
Target3.8
Herbie0
\[\left(a + b\right) \cdot 2 + \left(c + d\right) \cdot 2\]

Derivation

  1. Initial program 3.7

    \[\left(a + \left(b + \left(c + d\right)\right)\right) \cdot 2\]

  2. Taylor expanded around 0 2.8

    \[\leadsto \left(a + \color{blue}{\left(d + \left(b + c\right)\right)}\right) \cdot 2\]
  3. Using strategy rm

  4. Applied associate-+r+0

    \[\leadsto \color{blue}{\left(\left(a + d\right) + \left(b + c\right)\right)} \cdot 2\]

  5. Final simplification0

    \[\leadsto \left(\left(a + d\right) + \left(b + c\right)\right) \cdot 2\]

Reproduce

herbie shell --seed 2020042 
(FPCore (a b c d)
  :name "Expression, p6"
  :precision binary64
  :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))