1 - \left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-0.284496736 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(1.421413741 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-1.453152027 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}\frac{1 - {\left(\left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-0.284496736 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(1.421413741 + \frac{\frac{1}{\sqrt[3]{1 + 0.3275911 \cdot \left|x\right|} \cdot \sqrt[3]{1 + 0.3275911 \cdot \left|x\right|}}}{\sqrt[3]{1 + 0.3275911 \cdot \left|x\right|}} \cdot \left(-1.453152027 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-x \cdot x}\right)}^{3}}{1 + \left(\left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-0.284496736 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(1.421413741 + \frac{\frac{1}{\sqrt[3]{1 + 0.3275911 \cdot \left|x\right|} \cdot \sqrt[3]{1 + 0.3275911 \cdot \left|x\right|}}}{\sqrt[3]{1 + 0.3275911 \cdot \left|x\right|}} \cdot \left(-1.453152027 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-x \cdot x} + \left(\left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-0.284496736 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(1.421413741 + \frac{\frac{1}{\sqrt[3]{1 + 0.3275911 \cdot \left|x\right|} \cdot \sqrt[3]{1 + 0.3275911 \cdot \left|x\right|}}}{\sqrt[3]{1 + 0.3275911 \cdot \left|x\right|}} \cdot \left(-1.453152027 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-x \cdot x}\right) \cdot \left(\left(\frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(0.254829592 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(-0.284496736 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot \left(1.421413741 + \frac{\frac{1}{\sqrt[3]{1 + 0.3275911 \cdot \left|x\right|} \cdot \sqrt[3]{1 + 0.3275911 \cdot \left|x\right|}}}{\sqrt[3]{1 + 0.3275911 \cdot \left|x\right|}} \cdot \left(-1.453152027 + \frac{1}{1 + 0.3275911 \cdot \left|x\right|} \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-x \cdot x}\right)\right)}(FPCore (x)
:precision binary64
(-
1.0
(*
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
0.254829592
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
-0.284496736
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
1.421413741
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
-1.453152027
(* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) 1.061405429)))))))))
(exp (- (* (fabs x) (fabs x)))))))(FPCore (x)
:precision binary64
(/
(-
1.0
(pow
(*
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
0.254829592
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
-0.284496736
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
1.421413741
(*
(/
(/
1.0
(*
(cbrt (+ 1.0 (* 0.3275911 (fabs x))))
(cbrt (+ 1.0 (* 0.3275911 (fabs x))))))
(cbrt (+ 1.0 (* 0.3275911 (fabs x)))))
(+
-1.453152027
(* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) 1.061405429)))))))))
(exp (- (* x x))))
3.0))
(+
1.0
(+
(*
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
0.254829592
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
-0.284496736
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
1.421413741
(*
(/
(/
1.0
(*
(cbrt (+ 1.0 (* 0.3275911 (fabs x))))
(cbrt (+ 1.0 (* 0.3275911 (fabs x))))))
(cbrt (+ 1.0 (* 0.3275911 (fabs x)))))
(+
-1.453152027
(* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) 1.061405429)))))))))
(exp (- (* x x))))
(*
(*
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
0.254829592
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
-0.284496736
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
1.421413741
(*
(/
(/
1.0
(*
(cbrt (+ 1.0 (* 0.3275911 (fabs x))))
(cbrt (+ 1.0 (* 0.3275911 (fabs x))))))
(cbrt (+ 1.0 (* 0.3275911 (fabs x)))))
(+
-1.453152027
(* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) 1.061405429)))))))))
(exp (- (* x x))))
(*
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
0.254829592
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
-0.284496736
(*
(/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))
(+
1.421413741
(*
(/
(/
1.0
(*
(cbrt (+ 1.0 (* 0.3275911 (fabs x))))
(cbrt (+ 1.0 (* 0.3275911 (fabs x))))))
(cbrt (+ 1.0 (* 0.3275911 (fabs x)))))
(+
-1.453152027
(* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) 1.061405429)))))))))
(exp (- (* x x)))))))))double code(double x) {
return 1.0 - (((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (0.254829592 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (-0.284496736 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (1.421413741 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (-1.453152027 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * 1.061405429))))))))) * exp(-(fabs(x) * fabs(x))));
}
double code(double x) {
return (1.0 - pow((((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (0.254829592 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (-0.284496736 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (1.421413741 + (((1.0 / (cbrt(1.0 + (0.3275911 * fabs(x))) * cbrt(1.0 + (0.3275911 * fabs(x))))) / cbrt(1.0 + (0.3275911 * fabs(x)))) * (-1.453152027 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * 1.061405429))))))))) * exp(-(x * x))), 3.0)) / (1.0 + ((((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (0.254829592 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (-0.284496736 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (1.421413741 + (((1.0 / (cbrt(1.0 + (0.3275911 * fabs(x))) * cbrt(1.0 + (0.3275911 * fabs(x))))) / cbrt(1.0 + (0.3275911 * fabs(x)))) * (-1.453152027 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * 1.061405429))))))))) * exp(-(x * x))) + ((((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (0.254829592 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (-0.284496736 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (1.421413741 + (((1.0 / (cbrt(1.0 + (0.3275911 * fabs(x))) * cbrt(1.0 + (0.3275911 * fabs(x))))) / cbrt(1.0 + (0.3275911 * fabs(x)))) * (-1.453152027 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * 1.061405429))))))))) * exp(-(x * x))) * (((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (0.254829592 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (-0.284496736 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * (1.421413741 + (((1.0 / (cbrt(1.0 + (0.3275911 * fabs(x))) * cbrt(1.0 + (0.3275911 * fabs(x))))) / cbrt(1.0 + (0.3275911 * fabs(x)))) * (-1.453152027 + ((1.0 / (1.0 + (0.3275911 * fabs(x)))) * 1.061405429))))))))) * exp(-(x * x))))));
}



Bits error versus x
Results
Initial program 13.9
rmApplied add-cube-cbrt_binary64_250014.0
Applied associate-/r*_binary64_240914.0
Simplified14.0
rmApplied flip3--_binary64_246913.9
Final simplification13.9
herbie shell --seed 2021024
(FPCore (x)
:name "Jmat.Real.erf"
:precision binary64
(- 1.0 (* (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) (+ 0.254829592 (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) (+ -0.284496736 (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) (+ 1.421413741 (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) (+ -1.453152027 (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) 1.061405429))))))))) (exp (- (* (fabs x) (fabs x)))))))