Average Error: 13.9 → 13.1
Time: 16.7s
Precision: 64
\[1 - \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-1.45315202700000001 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot 1.0614054289999999\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}\]
↓
\[\frac{{1}^{3} - \sqrt{{\left(\left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}\right)}^{3}} \cdot \sqrt{{\left(\left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}\right)}^{3}}}{1 \cdot 1 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(\left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right) \cdot \frac{1}{e^{{\left(\left|x\right|\right)}^{2}}}\right)\right) \cdot \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(\left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right) \cdot \frac{1}{e^{{\left(\left|x\right|\right)}^{2}}}\right) + 1\right)}\]
1 - \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-1.45315202700000001 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot 1.0614054289999999\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}
↓
\frac{{1}^{3} - \sqrt{{\left(\left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}\right)}^{3}} \cdot \sqrt{{\left(\left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}\right)}^{3}}}{1 \cdot 1 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(\left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right) \cdot \frac{1}{e^{{\left(\left|x\right|\right)}^{2}}}\right)\right) \cdot \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(\left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right) \cdot \frac{1}{e^{{\left(\left|x\right|\right)}^{2}}}\right) + 1\right)}
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 ((pow(1.0, 3.0) - (sqrt(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 / (1.0 + (0.3275911 * fabs(x)))) * -1.453152027) + (1.061405429 * (1.0 / (pow(((0.3275911 * fabs(x)) + 1.0), 2.0) / 1.0)))))))))) * exp(-(fabs(x) * fabs(x)))), 3.0)) * sqrt(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 / (1.0 + (0.3275911 * fabs(x)))) * -1.453152027) + (1.061405429 * (1.0 / (pow(((0.3275911 * fabs(x)) + 1.0), 2.0) / 1.0)))))))))) * exp(-(fabs(x) * fabs(x)))), 3.0)))) / ((1.0 * 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 / (1.0 + (0.3275911 * fabs(x)))) * -1.453152027) + (1.061405429 * (1.0 / (pow(((0.3275911 * fabs(x)) + 1.0), 2.0) / 1.0))))))))) * (1.0 / exp(pow(fabs(x), 2.0))))) * (((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) + (1.061405429 * (1.0 / (pow(((0.3275911 * fabs(x)) + 1.0), 2.0) / 1.0))))))))) * (1.0 / exp(pow(fabs(x), 2.0))))) + 1.0))));
}

Error

Bits error versus x

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Initial program 13.9

    \[1 - \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-1.45315202700000001 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot 1.0614054289999999\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}\]
  2. Using strategy rm

  3. Applied distribute-lft-in13.9

    \[\leadsto 1 - \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \color{blue}{\left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot 1.0614054289999999\right)\right)}\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}\]

  4. Simplified13.9

    \[\leadsto 1 - \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + \color{blue}{1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}}\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}\]
  5. Using strategy rm

  6. Applied flip3--13.8

    \[\leadsto \color{blue}{\frac{{1}^{3} - {\left(\left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}\right)}^{3}}{1 \cdot 1 + \left(\left(\left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}\right) \cdot \left(\left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}\right) + 1 \cdot \left(\left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}\right)\right)}}\]

  7. Simplified13.8

    \[\leadsto \frac{{1}^{3} - {\left(\left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}\right)}^{3}}{\color{blue}{1 \cdot 1 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(\left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right) \cdot \frac{1}{e^{{\left(\left|x\right|\right)}^{2}}}\right)\right) \cdot \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(\left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right) \cdot \frac{1}{e^{{\left(\left|x\right|\right)}^{2}}}\right) + 1\right)}}\]
  8. Using strategy rm

  9. Applied add-sqr-sqrt13.1

    \[\leadsto \frac{{1}^{3} - \color{blue}{\sqrt{{\left(\left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}\right)}^{3}} \cdot \sqrt{{\left(\left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}\right)}^{3}}}}{1 \cdot 1 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(\left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right) \cdot \frac{1}{e^{{\left(\left|x\right|\right)}^{2}}}\right)\right) \cdot \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(\left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right) \cdot \frac{1}{e^{{\left(\left|x\right|\right)}^{2}}}\right) + 1\right)}\]

  10. Final simplification13.1

    \[\leadsto \frac{{1}^{3} - \sqrt{{\left(\left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}\right)}^{3}} \cdot \sqrt{{\left(\left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}\right)}^{3}}}{1 \cdot 1 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(\left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right) \cdot \frac{1}{e^{{\left(\left|x\right|\right)}^{2}}}\right)\right) \cdot \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(\left(0.25482959199999999 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(-0.284496735999999972 + \frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot \left(1.42141374100000006 + \left(\frac{1}{1 + 0.32759110000000002 \cdot \left|x\right|} \cdot -1.45315202700000001 + 1.0614054289999999 \cdot \frac{1}{\frac{{\left(0.32759110000000002 \cdot \left|x\right| + 1\right)}^{2}}{1}}\right)\right)\right)\right) \cdot \frac{1}{e^{{\left(\left|x\right|\right)}^{2}}}\right) + 1\right)}\]

Reproduce

herbie shell --seed 2020100 
(FPCore (x)
  :name "Jmat.Real.erf"
  :precision binary64
  (- 1 (* (* (/ 1 (+ 1 (* 0.3275911 (fabs x)))) (+ 0.254829592 (* (/ 1 (+ 1 (* 0.3275911 (fabs x)))) (+ -0.284496736 (* (/ 1 (+ 1 (* 0.3275911 (fabs x)))) (+ 1.421413741 (* (/ 1 (+ 1 (* 0.3275911 (fabs x)))) (+ -1.453152027 (* (/ 1 (+ 1 (* 0.3275911 (fabs x)))) 1.061405429))))))))) (exp (- (* (fabs x) (fabs x)))))))