Average Error: 11.8 → 0.1
Time: 7.3s
Precision: binary64
Cost: 960
\[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
\[x + \frac{-2}{\frac{1}{\frac{y}{2 \cdot z}} - \frac{t}{z}} \]
(FPCore (x y z t)
 :precision binary64
 (- x (/ (* (* y 2.0) z) (- (* (* z 2.0) z) (* y t)))))
(FPCore (x y z t)
 :precision binary64
 (+ x (/ -2.0 (- (/ 1.0 (/ y (* 2.0 z))) (/ t z)))))
double code(double x, double y, double z, double t) {
	return x - (((y * 2.0) * z) / (((z * 2.0) * z) - (y * t)));
}
double code(double x, double y, double z, double t) {
	return x + (-2.0 / ((1.0 / (y / (2.0 * z))) - (t / z)));
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    code = x - (((y * 2.0d0) * z) / (((z * 2.0d0) * z) - (y * t)))
end function
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    code = x + ((-2.0d0) / ((1.0d0 / (y / (2.0d0 * z))) - (t / z)))
end function
public static double code(double x, double y, double z, double t) {
	return x - (((y * 2.0) * z) / (((z * 2.0) * z) - (y * t)));
}
public static double code(double x, double y, double z, double t) {
	return x + (-2.0 / ((1.0 / (y / (2.0 * z))) - (t / z)));
}
def code(x, y, z, t):
	return x - (((y * 2.0) * z) / (((z * 2.0) * z) - (y * t)))
def code(x, y, z, t):
	return x + (-2.0 / ((1.0 / (y / (2.0 * z))) - (t / z)))
function code(x, y, z, t)
	return Float64(x - Float64(Float64(Float64(y * 2.0) * z) / Float64(Float64(Float64(z * 2.0) * z) - Float64(y * t))))
end
function code(x, y, z, t)
	return Float64(x + Float64(-2.0 / Float64(Float64(1.0 / Float64(y / Float64(2.0 * z))) - Float64(t / z))))
end
function tmp = code(x, y, z, t)
	tmp = x - (((y * 2.0) * z) / (((z * 2.0) * z) - (y * t)));
end
function tmp = code(x, y, z, t)
	tmp = x + (-2.0 / ((1.0 / (y / (2.0 * z))) - (t / z)));
end
code[x_, y_, z_, t_] := N[(x - N[(N[(N[(y * 2.0), $MachinePrecision] * z), $MachinePrecision] / N[(N[(N[(z * 2.0), $MachinePrecision] * z), $MachinePrecision] - N[(y * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
code[x_, y_, z_, t_] := N[(x + N[(-2.0 / N[(N[(1.0 / N[(y / N[(2.0 * z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(t / z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t}
x + \frac{-2}{\frac{1}{\frac{y}{2 \cdot z}} - \frac{t}{z}}

Error

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original11.8
Target0.1
Herbie0.1
\[x - \frac{1}{\frac{z}{y} - \frac{\frac{t}{2}}{z}} \]

Derivation

  1. Initial program 11.8

    \[x - \frac{\left(y \cdot 2\right) \cdot z}{\left(z \cdot 2\right) \cdot z - y \cdot t} \]
  2. Simplified0.1

    \[\leadsto \color{blue}{x + \frac{-2}{2 \cdot \frac{z}{y} - \frac{t}{z}}} \]
    Proof
    (+.f64 x (/.f64 -2 (-.f64 (*.f64 2 (/.f64 z y)) (/.f64 t z)))): 0 points increase in error, 0 points decrease in error
    (+.f64 x (/.f64 (Rewrite<= metadata-eval (neg.f64 2)) (-.f64 (*.f64 2 (/.f64 z y)) (/.f64 t z)))): 0 points increase in error, 0 points decrease in error
    (+.f64 x (/.f64 (neg.f64 2) (-.f64 (Rewrite=> associate-*r/_binary64 (/.f64 (*.f64 2 z) y)) (/.f64 t z)))): 0 points increase in error, 0 points decrease in error
    (+.f64 x (/.f64 (neg.f64 2) (-.f64 (/.f64 (Rewrite<= *-commutative_binary64 (*.f64 z 2)) y) (/.f64 t z)))): 0 points increase in error, 0 points decrease in error
    (+.f64 x (/.f64 (neg.f64 2) (-.f64 (/.f64 (*.f64 z 2) y) (Rewrite<= *-lft-identity_binary64 (*.f64 1 (/.f64 t z)))))): 0 points increase in error, 0 points decrease in error
    (+.f64 x (/.f64 (neg.f64 2) (-.f64 (/.f64 (*.f64 z 2) y) (*.f64 (Rewrite<= *-inverses_binary64 (/.f64 y y)) (/.f64 t z))))): 0 points increase in error, 0 points decrease in error
    (+.f64 x (/.f64 (neg.f64 2) (-.f64 (/.f64 (*.f64 z 2) y) (Rewrite<= times-frac_binary64 (/.f64 (*.f64 y t) (*.f64 y z)))))): 22 points increase in error, 0 points decrease in error
    (+.f64 x (/.f64 (neg.f64 2) (-.f64 (/.f64 (*.f64 z 2) y) (Rewrite<= associate-/l/_binary64 (/.f64 (/.f64 (*.f64 y t) z) y))))): 3 points increase in error, 18 points decrease in error
    (+.f64 x (/.f64 (neg.f64 2) (Rewrite<= div-sub_binary64 (/.f64 (-.f64 (*.f64 z 2) (/.f64 (*.f64 y t) z)) y)))): 0 points increase in error, 0 points decrease in error
    (+.f64 x (/.f64 (neg.f64 2) (/.f64 (-.f64 (Rewrite<= /-rgt-identity_binary64 (/.f64 (*.f64 z 2) 1)) (/.f64 (*.f64 y t) z)) y))): 0 points increase in error, 0 points decrease in error
    (+.f64 x (/.f64 (neg.f64 2) (/.f64 (-.f64 (/.f64 (*.f64 z 2) (Rewrite<= *-inverses_binary64 (/.f64 z z))) (/.f64 (*.f64 y t) z)) y))): 0 points increase in error, 0 points decrease in error
    (+.f64 x (/.f64 (neg.f64 2) (/.f64 (-.f64 (Rewrite<= associate-/l*_binary64 (/.f64 (*.f64 (*.f64 z 2) z) z)) (/.f64 (*.f64 y t) z)) y))): 19 points increase in error, 0 points decrease in error
    (+.f64 x (/.f64 (neg.f64 2) (/.f64 (Rewrite<= div-sub_binary64 (/.f64 (-.f64 (*.f64 (*.f64 z 2) z) (*.f64 y t)) z)) y))): 0 points increase in error, 0 points decrease in error
    (+.f64 x (Rewrite<= distribute-neg-frac_binary64 (neg.f64 (/.f64 2 (/.f64 (/.f64 (-.f64 (*.f64 (*.f64 z 2) z) (*.f64 y t)) z) y))))): 0 points increase in error, 0 points decrease in error
    (+.f64 x (neg.f64 (Rewrite<= associate-/l*_binary64 (/.f64 (*.f64 2 y) (/.f64 (-.f64 (*.f64 (*.f64 z 2) z) (*.f64 y t)) z))))): 3 points increase in error, 11 points decrease in error
    (+.f64 x (neg.f64 (/.f64 (Rewrite<= *-commutative_binary64 (*.f64 y 2)) (/.f64 (-.f64 (*.f64 (*.f64 z 2) z) (*.f64 y t)) z)))): 0 points increase in error, 0 points decrease in error
    (+.f64 x (neg.f64 (Rewrite<= associate-/l*_binary64 (/.f64 (*.f64 (*.f64 y 2) z) (-.f64 (*.f64 (*.f64 z 2) z) (*.f64 y t)))))): 45 points increase in error, 7 points decrease in error
    (Rewrite<= sub-neg_binary64 (-.f64 x (/.f64 (*.f64 (*.f64 y 2) z) (-.f64 (*.f64 (*.f64 z 2) z) (*.f64 y t))))): 0 points increase in error, 0 points decrease in error
  3. Applied egg-rr0.1

    \[\leadsto x + \frac{-2}{\color{blue}{\frac{1}{\frac{y}{2 \cdot z}}} - \frac{t}{z}} \]
  4. Final simplification0.1

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

Alternatives

Alternative 1
Error0.1
Cost832
\[x + \frac{-2}{2 \cdot \frac{z}{y} - \frac{t}{z}} \]
Alternative 2
Error6.9
Cost712
\[\begin{array}{l} t_1 := x - \frac{y}{z}\\ \mathbf{if}\;z \leq -1.1483412482215439 \cdot 10^{-5}:\\ \;\;\;\;t_1\\ \mathbf{elif}\;z \leq 1.0450506643503564 \cdot 10^{+23}:\\ \;\;\;\;x + z \cdot \frac{2}{t}\\ \mathbf{else}:\\ \;\;\;\;t_1\\ \end{array} \]
Alternative 3
Error6.9
Cost712
\[\begin{array}{l} t_1 := x - \frac{y}{z}\\ \mathbf{if}\;z \leq -1.1483412482215439 \cdot 10^{-5}:\\ \;\;\;\;t_1\\ \mathbf{elif}\;z \leq 1.0450506643503564 \cdot 10^{+23}:\\ \;\;\;\;x + 2 \cdot \frac{z}{t}\\ \mathbf{else}:\\ \;\;\;\;t_1\\ \end{array} \]
Alternative 4
Error15.8
Cost584
\[\begin{array}{l} \mathbf{if}\;x \leq -2.0753880498485545 \cdot 10^{-278}:\\ \;\;\;\;x\\ \mathbf{elif}\;x \leq 1.490674323023235 \cdot 10^{-235}:\\ \;\;\;\;2 \cdot \frac{z}{t}\\ \mathbf{else}:\\ \;\;\;\;x\\ \end{array} \]
Alternative 5
Error11.6
Cost584
\[\begin{array}{l} t_1 := x - \frac{y}{z}\\ \mathbf{if}\;z \leq -1.3747265254031916 \cdot 10^{+58}:\\ \;\;\;\;t_1\\ \mathbf{elif}\;z \leq 3.551102001696844 \cdot 10^{+84}:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;t_1\\ \end{array} \]
Alternative 6
Error16.0
Cost64
\[x \]

Error

Reproduce

herbie shell --seed 2022297 
(FPCore (x y z t)
  :name "Numeric.AD.Rank1.Halley:findZero from ad-4.2.4"
  :precision binary64

  :herbie-target
  (- x (/ 1.0 (- (/ z y) (/ (/ t 2.0) z))))

  (- x (/ (* (* y 2.0) z) (- (* (* z 2.0) z) (* y t)))))