\[\frac{\left(1 + \frac{1}{\varepsilon}\right) \cdot e^{-\left(1 - \varepsilon\right) \cdot x} - \left(\frac{1}{\varepsilon} - 1\right) \cdot e^{-\left(1 + \varepsilon\right) \cdot x}}{2}\]
Test:
NMSE Section 6.1 mentioned, A
Bits:
128 bits
Bits error versus x
Bits error versus eps
Time: 1.8 m
Input Error: 20.2
Output Error: 0.1
Log:
Profile: 🕒
\(\begin{cases} 1 & \text{when } x \le 12.645091f0 \\ \frac{\left(\frac{1}{{\left(e^{x}\right)}^{\left(1 - \varepsilon\right)}} + \frac{\frac{1}{\varepsilon}}{{\left(e^{x}\right)}^{\left(1 - \varepsilon\right)}}\right) + \left(e^{-(\varepsilon * x + x)_*} - \frac{\frac{1}{\varepsilon}}{e^{(\varepsilon * x + x)_*}}\right)}{2} & \text{otherwise} \end{cases}\)

    if x < 12.645091f0

    1. Started with
      \[\frac{\left(1 + \frac{1}{\varepsilon}\right) \cdot e^{-\left(1 - \varepsilon\right) \cdot x} - \left(\frac{1}{\varepsilon} - 1\right) \cdot e^{-\left(1 + \varepsilon\right) \cdot x}}{2}\]
      23.5
    2. Applied taylor to get
      \[\frac{\left(1 + \frac{1}{\varepsilon}\right) \cdot e^{-\left(1 - \varepsilon\right) \cdot x} - \left(\frac{1}{\varepsilon} - 1\right) \cdot e^{-\left(1 + \varepsilon\right) \cdot x}}{2} \leadsto \frac{2}{2}\]
      0
    3. Taylor expanded around 0 to get
      \[\frac{\color{red}{2}}{2} \leadsto \frac{\color{blue}{2}}{2}\]
      0
    4. Applied simplify to get
      \[\color{red}{\frac{2}{2}} \leadsto \color{blue}{1}\]
      0

    if 12.645091f0 < x

    1. Started with
      \[\frac{\left(1 + \frac{1}{\varepsilon}\right) \cdot e^{-\left(1 - \varepsilon\right) \cdot x} - \left(\frac{1}{\varepsilon} - 1\right) \cdot e^{-\left(1 + \varepsilon\right) \cdot x}}{2}\]
      0.5
    2. Using strategy rm
      0.5
    3. Applied add-cube-cbrt to get
      \[\frac{\color{red}{\left(1 + \frac{1}{\varepsilon}\right) \cdot e^{-\left(1 - \varepsilon\right) \cdot x} - \left(\frac{1}{\varepsilon} - 1\right) \cdot e^{-\left(1 + \varepsilon\right) \cdot x}}}{2} \leadsto \frac{\color{blue}{{\left(\sqrt[3]{\left(1 + \frac{1}{\varepsilon}\right) \cdot e^{-\left(1 - \varepsilon\right) \cdot x} - \left(\frac{1}{\varepsilon} - 1\right) \cdot e^{-\left(1 + \varepsilon\right) \cdot x}}\right)}^3}}{2}\]
      0.5
    4. Applied simplify to get
      \[\frac{{\color{red}{\left(\sqrt[3]{\left(1 + \frac{1}{\varepsilon}\right) \cdot e^{-\left(1 - \varepsilon\right) \cdot x} - \left(\frac{1}{\varepsilon} - 1\right) \cdot e^{-\left(1 + \varepsilon\right) \cdot x}}\right)}}^3}{2} \leadsto \frac{{\color{blue}{\left(\sqrt[3]{\frac{\frac{1}{\varepsilon} + 1}{{\left(e^{x}\right)}^{\left(1 - \varepsilon\right)}} - \frac{\frac{1}{\varepsilon} - 1}{e^{(\varepsilon * x + x)_*}}}\right)}}^3}{2}\]
      0.5
    5. Applied taylor to get
      \[\frac{{\left(\sqrt[3]{\frac{\frac{1}{\varepsilon} + 1}{{\left(e^{x}\right)}^{\left(1 - \varepsilon\right)}} - \frac{\frac{1}{\varepsilon} - 1}{e^{(\varepsilon * x + x)_*}}}\right)}^3}{2} \leadsto \frac{{\left(\sqrt[3]{\left(\frac{1}{\varepsilon \cdot {\left(e^{x}\right)}^{\left(1 - \varepsilon\right)}} + \left(\frac{1}{{\left(e^{x}\right)}^{\left(1 - \varepsilon\right)}} + \frac{1}{e^{(\varepsilon * x + x)_*}}\right)\right) - \frac{1}{\varepsilon \cdot e^{(\varepsilon * x + x)_*}}}\right)}^3}{2}\]
      0.4
    6. Taylor expanded around 0 to get
      \[\frac{{\color{red}{\left(\sqrt[3]{\left(\frac{1}{\varepsilon \cdot {\left(e^{x}\right)}^{\left(1 - \varepsilon\right)}} + \left(\frac{1}{{\left(e^{x}\right)}^{\left(1 - \varepsilon\right)}} + \frac{1}{e^{(\varepsilon * x + x)_*}}\right)\right) - \frac{1}{\varepsilon \cdot e^{(\varepsilon * x + x)_*}}}\right)}}^3}{2} \leadsto \frac{{\color{blue}{\left(\sqrt[3]{\left(\frac{1}{\varepsilon \cdot {\left(e^{x}\right)}^{\left(1 - \varepsilon\right)}} + \left(\frac{1}{{\left(e^{x}\right)}^{\left(1 - \varepsilon\right)}} + \frac{1}{e^{(\varepsilon * x + x)_*}}\right)\right) - \frac{1}{\varepsilon \cdot e^{(\varepsilon * x + x)_*}}}\right)}}^3}{2}\]
      0.4
    7. Applied simplify to get
      \[\frac{{\left(\sqrt[3]{\left(\frac{1}{\varepsilon \cdot {\left(e^{x}\right)}^{\left(1 - \varepsilon\right)}} + \left(\frac{1}{{\left(e^{x}\right)}^{\left(1 - \varepsilon\right)}} + \frac{1}{e^{(\varepsilon * x + x)_*}}\right)\right) - \frac{1}{\varepsilon \cdot e^{(\varepsilon * x + x)_*}}}\right)}^3}{2} \leadsto \frac{\left(\frac{1}{{\left(e^{x}\right)}^{\left(1 - \varepsilon\right)}} + \frac{\frac{1}{\varepsilon}}{{\left(e^{x}\right)}^{\left(1 - \varepsilon\right)}}\right) + \left(e^{-(\varepsilon * x + x)_*} - \frac{\frac{1}{\varepsilon}}{e^{(\varepsilon * x + x)_*}}\right)}{2}\]
      0.5

    8. Applied final simplification

  1. Removed slow pow expressions

Original test:


(lambda ((x default) (eps default))
  #:name "NMSE Section 6.1 mentioned, A"
  (/ (- (* (+ 1 (/ 1 eps)) (exp (- (* (- 1 eps) x)))) (* (- (/ 1 eps) 1) (exp (- (* (+ 1 eps) x))))) 2))