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{\frac{1 - {\left(\frac{0.254829592 + \frac{-0.284496736 + \frac{1.421413741 + \frac{-1.453152027 + \frac{1.061405429}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{\left(1 + 0.3275911 \cdot \left|x\right|\right) \cdot e^{{\left(\left|x\right|\right)}^{2}}}\right)}^{3} \cdot \left({\left(\frac{\sqrt{0.254829592 + \frac{-0.284496736 + \frac{1.421413741 + \frac{-1.453152027 + \frac{1.061405429}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}}{1 + 0.3275911 \cdot \left|x\right|}\right)}^{3} \cdot {\left(\frac{\sqrt{0.254829592 + \frac{-0.284496736 + \frac{1.421413741 + \frac{-1.453152027 + \frac{1.061405429}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}}{e^{{\left(\left|x\right|\right)}^{2}}}\right)}^{3}\right)}{1 + \sqrt{{\left(\frac{0.254829592 + \frac{-0.284496736 + \frac{1.421413741 + \frac{-1.453152027 + \frac{1.061405429}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{\left(1 + 0.3275911 \cdot \left|x\right|\right) \cdot e^{{\left(\left|x\right|\right)}^{2}}}\right)}^{3}} \cdot \sqrt{{\left(\frac{\sqrt{0.254829592 + \frac{-0.284496736 + \frac{1.421413741 + \frac{-1.453152027 + \frac{1.061405429}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}}{1 + 0.3275911 \cdot \left|x\right|}\right)}^{3} \cdot {\left(\frac{\sqrt{0.254829592 + \frac{-0.284496736 + \frac{1.421413741 + \frac{-1.453152027 + \frac{1.061405429}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}}{e^{{\left(\left|x\right|\right)}^{2}}}\right)}^{3}}}}{1 + \frac{0.254829592 + \frac{-0.284496736 + \frac{1.421413741 + \frac{-1.453152027 + \frac{1.061405429}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{\left(1 + 0.3275911 \cdot \left|x\right|\right) \cdot e^{{\left(\left|x\right|\right)}^{2}}} \cdot \left(1 + \frac{0.254829592 + \frac{-0.284496736 + \frac{1.421413741 + \frac{-1.453152027 + \frac{1.061405429}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{1 + 0.3275911 \cdot \left|x\right|}}{\left(1 + 0.3275911 \cdot \left|x\right|\right) \cdot e^{{\left(\left|x\right|\right)}^{2}}}\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
(/
(+
0.254829592
(/
(+
-0.284496736
(/
(+
1.421413741
(/
(+ -1.453152027 (/ 1.061405429 (+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(* (+ 1.0 (* 0.3275911 (fabs x))) (exp (pow (fabs x) 2.0))))
3.0)
(*
(pow
(/
(sqrt
(+
0.254829592
(/
(+
-0.284496736
(/
(+
1.421413741
(/
(+ -1.453152027 (/ 1.061405429 (+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x))))))
(+ 1.0 (* 0.3275911 (fabs x))))
3.0)
(pow
(/
(sqrt
(+
0.254829592
(/
(+
-0.284496736
(/
(+
1.421413741
(/
(+ -1.453152027 (/ 1.061405429 (+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x))))))
(exp (pow (fabs x) 2.0)))
3.0))))
(+
1.0
(*
(sqrt
(pow
(/
(+
0.254829592
(/
(+
-0.284496736
(/
(+
1.421413741
(/
(+ -1.453152027 (/ 1.061405429 (+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(* (+ 1.0 (* 0.3275911 (fabs x))) (exp (pow (fabs x) 2.0))))
3.0))
(sqrt
(*
(pow
(/
(sqrt
(+
0.254829592
(/
(+
-0.284496736
(/
(+
1.421413741
(/
(+ -1.453152027 (/ 1.061405429 (+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x))))))
(+ 1.0 (* 0.3275911 (fabs x))))
3.0)
(pow
(/
(sqrt
(+
0.254829592
(/
(+
-0.284496736
(/
(+
1.421413741
(/
(+ -1.453152027 (/ 1.061405429 (+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x))))))
(exp (pow (fabs x) 2.0)))
3.0))))))
(+
1.0
(*
(/
(+
0.254829592
(/
(+
-0.284496736
(/
(+
1.421413741
(/
(+ -1.453152027 (/ 1.061405429 (+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(* (+ 1.0 (* 0.3275911 (fabs x))) (exp (pow (fabs x) 2.0))))
(+
1.0
(/
(+
0.254829592
(/
(+
-0.284496736
(/
(+
1.421413741
(/
(+ -1.453152027 (/ 1.061405429 (+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(+ 1.0 (* 0.3275911 (fabs x)))))
(* (+ 1.0 (* 0.3275911 (fabs x))) (exp (pow (fabs x) 2.0)))))))))double code(double x) {
return ((double) (1.0 - ((double) (((double) ((1.0 / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))) * ((double) (0.254829592 + ((double) ((1.0 / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))) * ((double) (-0.284496736 + ((double) ((1.0 / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))) * ((double) (1.421413741 + ((double) ((1.0 / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))) * ((double) (-1.453152027 + ((double) ((1.0 / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))) * 1.061405429)))))))))))))))))) * ((double) exp(((double) -(((double) (((double) fabs(x)) * ((double) fabs(x))))))))))));
}
double code(double x) {
return ((((double) (1.0 - ((double) (((double) pow((((double) (0.254829592 + (((double) (-0.284496736 + (((double) (1.421413741 + (((double) (-1.453152027 + (1.061405429 / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x)))))) * ((double) exp(((double) pow(((double) fabs(x)), 2.0))))))), 3.0)) * ((double) (((double) pow((((double) sqrt(((double) (0.254829592 + (((double) (-0.284496736 + (((double) (1.421413741 + (((double) (-1.453152027 + (1.061405429 / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))), 3.0)) * ((double) pow((((double) sqrt(((double) (0.254829592 + (((double) (-0.284496736 + (((double) (1.421413741 + (((double) (-1.453152027 + (1.061405429 / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))))) / ((double) exp(((double) pow(((double) fabs(x)), 2.0))))), 3.0)))))))) / ((double) (1.0 + ((double) (((double) sqrt(((double) pow((((double) (0.254829592 + (((double) (-0.284496736 + (((double) (1.421413741 + (((double) (-1.453152027 + (1.061405429 / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x)))))) * ((double) exp(((double) pow(((double) fabs(x)), 2.0))))))), 3.0)))) * ((double) sqrt(((double) (((double) pow((((double) sqrt(((double) (0.254829592 + (((double) (-0.284496736 + (((double) (1.421413741 + (((double) (-1.453152027 + (1.061405429 / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))), 3.0)) * ((double) pow((((double) sqrt(((double) (0.254829592 + (((double) (-0.284496736 + (((double) (1.421413741 + (((double) (-1.453152027 + (1.061405429 / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))))) / ((double) exp(((double) pow(((double) fabs(x)), 2.0))))), 3.0))))))))))) / ((double) (1.0 + ((double) ((((double) (0.254829592 + (((double) (-0.284496736 + (((double) (1.421413741 + (((double) (-1.453152027 + (1.061405429 / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x)))))) * ((double) exp(((double) pow(((double) fabs(x)), 2.0))))))) * ((double) (1.0 + (((double) (0.254829592 + (((double) (-0.284496736 + (((double) (1.421413741 + (((double) (-1.453152027 + (1.061405429 / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x))))))))) / ((double) (((double) (1.0 + ((double) (0.3275911 * ((double) fabs(x)))))) * ((double) exp(((double) pow(((double) fabs(x)), 2.0))))))))))))));
}



Bits error versus x
Results
Initial program 13.8
Simplified13.8
rmApplied flip3--_binary6413.8
Simplified13.8
Simplified13.8
rmApplied add-sqr-sqrt_binary6413.0
rmApplied add-sqr-sqrt_binary6413.1
Applied times-frac_binary6413.1
Applied unpow-prod-down_binary6413.1
rmApplied flip--_binary6413.1
Simplified11.7
Final simplification11.7
herbie shell --seed 2020210
(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)))))))