Curve intersection, scale width based on ribbon orientation

Percentage Accurate: 97.3% → 99.1%
Time: 10.8s
Alternatives: 8
Speedup: 27.0×

Specification

?
\[\left(\left(\left(0 \leq normAngle \land normAngle \leq \frac{\mathsf{PI}\left(\right)}{2}\right) \land \left(-1 \leq n0\_i \land n0\_i \leq 1\right)\right) \land \left(-1 \leq n1\_i \land n1\_i \leq 1\right)\right) \land \left(2.328306437 \cdot 10^{-10} \leq u \land u \leq 1\right)\]
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1}{\sin normAngle}\\ \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot t\_0\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot t\_0\right) \cdot n1\_i \end{array} \end{array} \]
(FPCore (normAngle u n0_i n1_i)
 :precision binary32
 (let* ((t_0 (/ 1.0 (sin normAngle))))
   (+
    (* (* (sin (* (- 1.0 u) normAngle)) t_0) n0_i)
    (* (* (sin (* u normAngle)) t_0) n1_i))))
float code(float normAngle, float u, float n0_i, float n1_i) {
	float t_0 = 1.0f / sinf(normAngle);
	return ((sinf(((1.0f - u) * normAngle)) * t_0) * n0_i) + ((sinf((u * normAngle)) * t_0) * n1_i);
}
real(4) function code(normangle, u, n0_i, n1_i)
    real(4), intent (in) :: normangle
    real(4), intent (in) :: u
    real(4), intent (in) :: n0_i
    real(4), intent (in) :: n1_i
    real(4) :: t_0
    t_0 = 1.0e0 / sin(normangle)
    code = ((sin(((1.0e0 - u) * normangle)) * t_0) * n0_i) + ((sin((u * normangle)) * t_0) * n1_i)
end function
function code(normAngle, u, n0_i, n1_i)
	t_0 = Float32(Float32(1.0) / sin(normAngle))
	return Float32(Float32(Float32(sin(Float32(Float32(Float32(1.0) - u) * normAngle)) * t_0) * n0_i) + Float32(Float32(sin(Float32(u * normAngle)) * t_0) * n1_i))
end
function tmp = code(normAngle, u, n0_i, n1_i)
	t_0 = single(1.0) / sin(normAngle);
	tmp = ((sin(((single(1.0) - u) * normAngle)) * t_0) * n0_i) + ((sin((u * normAngle)) * t_0) * n1_i);
end
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{1}{\sin normAngle}\\
\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot t\_0\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot t\_0\right) \cdot n1\_i
\end{array}
\end{array}

Sampling outcomes in binary32 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 8 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 97.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1}{\sin normAngle}\\ \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot t\_0\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot t\_0\right) \cdot n1\_i \end{array} \end{array} \]
(FPCore (normAngle u n0_i n1_i)
 :precision binary32
 (let* ((t_0 (/ 1.0 (sin normAngle))))
   (+
    (* (* (sin (* (- 1.0 u) normAngle)) t_0) n0_i)
    (* (* (sin (* u normAngle)) t_0) n1_i))))
float code(float normAngle, float u, float n0_i, float n1_i) {
	float t_0 = 1.0f / sinf(normAngle);
	return ((sinf(((1.0f - u) * normAngle)) * t_0) * n0_i) + ((sinf((u * normAngle)) * t_0) * n1_i);
}
real(4) function code(normangle, u, n0_i, n1_i)
    real(4), intent (in) :: normangle
    real(4), intent (in) :: u
    real(4), intent (in) :: n0_i
    real(4), intent (in) :: n1_i
    real(4) :: t_0
    t_0 = 1.0e0 / sin(normangle)
    code = ((sin(((1.0e0 - u) * normangle)) * t_0) * n0_i) + ((sin((u * normangle)) * t_0) * n1_i)
end function
function code(normAngle, u, n0_i, n1_i)
	t_0 = Float32(Float32(1.0) / sin(normAngle))
	return Float32(Float32(Float32(sin(Float32(Float32(Float32(1.0) - u) * normAngle)) * t_0) * n0_i) + Float32(Float32(sin(Float32(u * normAngle)) * t_0) * n1_i))
end
function tmp = code(normAngle, u, n0_i, n1_i)
	t_0 = single(1.0) / sin(normAngle);
	tmp = ((sin(((single(1.0) - u) * normAngle)) * t_0) * n0_i) + ((sin((u * normAngle)) * t_0) * n1_i);
end
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{1}{\sin normAngle}\\
\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot t\_0\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot t\_0\right) \cdot n1\_i
\end{array}
\end{array}

Alternative 1: 99.1% accurate, 1.3× speedup?

\[\begin{array}{l} \\ n1\_i \cdot \left(\frac{normAngle}{\sin normAngle} \cdot u\right) + n0\_i \cdot \frac{\sin \left(\left(1 - u\right) \cdot normAngle\right)}{\sin normAngle} \end{array} \]
(FPCore (normAngle u n0_i n1_i)
 :precision binary32
 (+
  (* n1_i (* (/ normAngle (sin normAngle)) u))
  (* n0_i (/ (sin (* (- 1.0 u) normAngle)) (sin normAngle)))))
float code(float normAngle, float u, float n0_i, float n1_i) {
	return (n1_i * ((normAngle / sinf(normAngle)) * u)) + (n0_i * (sinf(((1.0f - u) * normAngle)) / sinf(normAngle)));
}
real(4) function code(normangle, u, n0_i, n1_i)
    real(4), intent (in) :: normangle
    real(4), intent (in) :: u
    real(4), intent (in) :: n0_i
    real(4), intent (in) :: n1_i
    code = (n1_i * ((normangle / sin(normangle)) * u)) + (n0_i * (sin(((1.0e0 - u) * normangle)) / sin(normangle)))
end function
function code(normAngle, u, n0_i, n1_i)
	return Float32(Float32(n1_i * Float32(Float32(normAngle / sin(normAngle)) * u)) + Float32(n0_i * Float32(sin(Float32(Float32(Float32(1.0) - u) * normAngle)) / sin(normAngle))))
end
function tmp = code(normAngle, u, n0_i, n1_i)
	tmp = (n1_i * ((normAngle / sin(normAngle)) * u)) + (n0_i * (sin(((single(1.0) - u) * normAngle)) / sin(normAngle)));
end
\begin{array}{l}

\\
n1\_i \cdot \left(\frac{normAngle}{\sin normAngle} \cdot u\right) + n0\_i \cdot \frac{\sin \left(\left(1 - u\right) \cdot normAngle\right)}{\sin normAngle}
\end{array}
Derivation
  1. Initial program 96.9%

    \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
  2. Add Preprocessing
  3. Taylor expanded in u around 0

    \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \color{blue}{\frac{normAngle \cdot u}{\sin normAngle}} \cdot n1\_i \]
  4. Step-by-step derivation
    1. associate-*l/N/A

      \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \color{blue}{\left(\frac{normAngle}{\sin normAngle} \cdot u\right)} \cdot n1\_i \]
    2. lower-*.f32N/A

      \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \color{blue}{\left(\frac{normAngle}{\sin normAngle} \cdot u\right)} \cdot n1\_i \]
    3. lower-/.f32N/A

      \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\color{blue}{\frac{normAngle}{\sin normAngle}} \cdot u\right) \cdot n1\_i \]
    4. lower-sin.f3298.3

      \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\frac{normAngle}{\color{blue}{\sin normAngle}} \cdot u\right) \cdot n1\_i \]
  5. Applied rewrites98.3%

    \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \color{blue}{\left(\frac{normAngle}{\sin normAngle} \cdot u\right)} \cdot n1\_i \]
  6. Step-by-step derivation
    1. lift-*.f32N/A

      \[\leadsto \color{blue}{\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right)} \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
    2. lift-/.f32N/A

      \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \color{blue}{\frac{1}{\sin normAngle}}\right) \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
    3. un-div-invN/A

      \[\leadsto \color{blue}{\frac{\sin \left(\left(1 - u\right) \cdot normAngle\right)}{\sin normAngle}} \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
    4. lower-/.f3299.3

      \[\leadsto \color{blue}{\frac{\sin \left(\left(1 - u\right) \cdot normAngle\right)}{\sin normAngle}} \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
    5. lift-*.f32N/A

      \[\leadsto \frac{\sin \color{blue}{\left(\left(1 - u\right) \cdot normAngle\right)}}{\sin normAngle} \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
    6. *-commutativeN/A

      \[\leadsto \frac{\sin \color{blue}{\left(normAngle \cdot \left(1 - u\right)\right)}}{\sin normAngle} \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
    7. lower-*.f3299.3

      \[\leadsto \frac{\sin \color{blue}{\left(normAngle \cdot \left(1 - u\right)\right)}}{\sin normAngle} \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
  7. Applied rewrites99.3%

    \[\leadsto \color{blue}{\frac{\sin \left(normAngle \cdot \left(1 - u\right)\right)}{\sin normAngle}} \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
  8. Final simplification99.3%

    \[\leadsto n1\_i \cdot \left(\frac{normAngle}{\sin normAngle} \cdot u\right) + n0\_i \cdot \frac{\sin \left(\left(1 - u\right) \cdot normAngle\right)}{\sin normAngle} \]
  9. Add Preprocessing

Alternative 2: 98.8% accurate, 3.5× speedup?

\[\begin{array}{l} \\ \left(1 - u\right) \cdot n0\_i + n1\_i \cdot \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \end{array} \]
(FPCore (normAngle u n0_i n1_i)
 :precision binary32
 (+ (* (- 1.0 u) n0_i) (* n1_i (* (/ normAngle (sin normAngle)) u))))
float code(float normAngle, float u, float n0_i, float n1_i) {
	return ((1.0f - u) * n0_i) + (n1_i * ((normAngle / sinf(normAngle)) * u));
}
real(4) function code(normangle, u, n0_i, n1_i)
    real(4), intent (in) :: normangle
    real(4), intent (in) :: u
    real(4), intent (in) :: n0_i
    real(4), intent (in) :: n1_i
    code = ((1.0e0 - u) * n0_i) + (n1_i * ((normangle / sin(normangle)) * u))
end function
function code(normAngle, u, n0_i, n1_i)
	return Float32(Float32(Float32(Float32(1.0) - u) * n0_i) + Float32(n1_i * Float32(Float32(normAngle / sin(normAngle)) * u)))
end
function tmp = code(normAngle, u, n0_i, n1_i)
	tmp = ((single(1.0) - u) * n0_i) + (n1_i * ((normAngle / sin(normAngle)) * u));
end
\begin{array}{l}

\\
\left(1 - u\right) \cdot n0\_i + n1\_i \cdot \left(\frac{normAngle}{\sin normAngle} \cdot u\right)
\end{array}
Derivation
  1. Initial program 96.9%

    \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
  2. Add Preprocessing
  3. Taylor expanded in u around 0

    \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \color{blue}{\frac{normAngle \cdot u}{\sin normAngle}} \cdot n1\_i \]
  4. Step-by-step derivation
    1. associate-*l/N/A

      \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \color{blue}{\left(\frac{normAngle}{\sin normAngle} \cdot u\right)} \cdot n1\_i \]
    2. lower-*.f32N/A

      \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \color{blue}{\left(\frac{normAngle}{\sin normAngle} \cdot u\right)} \cdot n1\_i \]
    3. lower-/.f32N/A

      \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\color{blue}{\frac{normAngle}{\sin normAngle}} \cdot u\right) \cdot n1\_i \]
    4. lower-sin.f3298.3

      \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\frac{normAngle}{\color{blue}{\sin normAngle}} \cdot u\right) \cdot n1\_i \]
  5. Applied rewrites98.3%

    \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \color{blue}{\left(\frac{normAngle}{\sin normAngle} \cdot u\right)} \cdot n1\_i \]
  6. Taylor expanded in normAngle around 0

    \[\leadsto \color{blue}{\left(1 - u\right)} \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
  7. Step-by-step derivation
    1. lower--.f3298.7

      \[\leadsto \color{blue}{\left(1 - u\right)} \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
  8. Applied rewrites98.7%

    \[\leadsto \color{blue}{\left(1 - u\right)} \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
  9. Final simplification98.7%

    \[\leadsto \left(1 - u\right) \cdot n0\_i + n1\_i \cdot \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \]
  10. Add Preprocessing

Alternative 3: 70.5% accurate, 21.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(n1\_i - n0\_i\right) \cdot u\\ \mathbf{if}\;n1\_i \leq -2.000000033724767 \cdot 10^{-16}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;n1\_i \leq 9.99999983775159 \cdot 10^{-18}:\\ \;\;\;\;n0\_i \cdot \left(1 - u\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (normAngle u n0_i n1_i)
 :precision binary32
 (let* ((t_0 (* (- n1_i n0_i) u)))
   (if (<= n1_i -2.000000033724767e-16)
     t_0
     (if (<= n1_i 9.99999983775159e-18) (* n0_i (- 1.0 u)) t_0))))
float code(float normAngle, float u, float n0_i, float n1_i) {
	float t_0 = (n1_i - n0_i) * u;
	float tmp;
	if (n1_i <= -2.000000033724767e-16f) {
		tmp = t_0;
	} else if (n1_i <= 9.99999983775159e-18f) {
		tmp = n0_i * (1.0f - u);
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(4) function code(normangle, u, n0_i, n1_i)
    real(4), intent (in) :: normangle
    real(4), intent (in) :: u
    real(4), intent (in) :: n0_i
    real(4), intent (in) :: n1_i
    real(4) :: t_0
    real(4) :: tmp
    t_0 = (n1_i - n0_i) * u
    if (n1_i <= (-2.000000033724767e-16)) then
        tmp = t_0
    else if (n1_i <= 9.99999983775159e-18) then
        tmp = n0_i * (1.0e0 - u)
    else
        tmp = t_0
    end if
    code = tmp
end function
function code(normAngle, u, n0_i, n1_i)
	t_0 = Float32(Float32(n1_i - n0_i) * u)
	tmp = Float32(0.0)
	if (n1_i <= Float32(-2.000000033724767e-16))
		tmp = t_0;
	elseif (n1_i <= Float32(9.99999983775159e-18))
		tmp = Float32(n0_i * Float32(Float32(1.0) - u));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(normAngle, u, n0_i, n1_i)
	t_0 = (n1_i - n0_i) * u;
	tmp = single(0.0);
	if (n1_i <= single(-2.000000033724767e-16))
		tmp = t_0;
	elseif (n1_i <= single(9.99999983775159e-18))
		tmp = n0_i * (single(1.0) - u);
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(n1\_i - n0\_i\right) \cdot u\\
\mathbf{if}\;n1\_i \leq -2.000000033724767 \cdot 10^{-16}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;n1\_i \leq 9.99999983775159 \cdot 10^{-18}:\\
\;\;\;\;n0\_i \cdot \left(1 - u\right)\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if n1_i < -2.00000003e-16 or 9.99999984e-18 < n1_i

    1. Initial program 94.0%

      \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
    2. Add Preprocessing
    3. Taylor expanded in normAngle around 0

      \[\leadsto \color{blue}{n0\_i \cdot \left(1 - u\right) + n1\_i \cdot u} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \color{blue}{\left(1 - u\right) \cdot n0\_i} + n1\_i \cdot u \]
      2. lower-fma.f32N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(1 - u, n0\_i, n1\_i \cdot u\right)} \]
      3. lower--.f32N/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{1 - u}, n0\_i, n1\_i \cdot u\right) \]
      4. lower-*.f3267.6

        \[\leadsto \mathsf{fma}\left(1 - u, n0\_i, \color{blue}{n1\_i \cdot u}\right) \]
    5. Applied rewrites67.5%

      \[\leadsto \color{blue}{\mathsf{fma}\left(1 - u, n0\_i, n1\_i \cdot u\right)} \]
    6. Taylor expanded in u around inf

      \[\leadsto u \cdot \color{blue}{\left(n1\_i + -1 \cdot n0\_i\right)} \]
    7. Step-by-step derivation
      1. Applied rewrites66.6%

        \[\leadsto \left(n1\_i - n0\_i\right) \cdot \color{blue}{u} \]

      if -2.00000003e-16 < n1_i < 9.99999984e-18

      1. Initial program 98.6%

        \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
      2. Add Preprocessing
      3. Taylor expanded in normAngle around 0

        \[\leadsto \color{blue}{n0\_i \cdot \left(1 - u\right) + n1\_i \cdot u} \]
      4. Step-by-step derivation
        1. *-commutativeN/A

          \[\leadsto \color{blue}{\left(1 - u\right) \cdot n0\_i} + n1\_i \cdot u \]
        2. lower-fma.f32N/A

          \[\leadsto \color{blue}{\mathsf{fma}\left(1 - u, n0\_i, n1\_i \cdot u\right)} \]
        3. lower--.f32N/A

          \[\leadsto \mathsf{fma}\left(\color{blue}{1 - u}, n0\_i, n1\_i \cdot u\right) \]
        4. lower-*.f3219.8

          \[\leadsto \mathsf{fma}\left(1 - u, n0\_i, \color{blue}{n1\_i \cdot u}\right) \]
      5. Applied rewrites19.8%

        \[\leadsto \color{blue}{\mathsf{fma}\left(1 - u, n0\_i, n1\_i \cdot u\right)} \]
      6. Step-by-step derivation
        1. Applied rewrites97.8%

          \[\leadsto n1\_i \cdot u + \color{blue}{n0\_i \cdot \left(1 - u\right)} \]
        2. Step-by-step derivation
          1. Applied rewrites98.2%

            \[\leadsto n1\_i \cdot u + \left(n0\_i + \color{blue}{\left(-u\right) \cdot n0\_i}\right) \]
          2. Taylor expanded in n0_i around -inf

            \[\leadsto -1 \cdot \color{blue}{\left(n0\_i \cdot \left(u - 1\right)\right)} \]
          3. Step-by-step derivation
            1. Applied rewrites78.7%

              \[\leadsto n0\_i \cdot \color{blue}{\left(1 - u\right)} \]
          4. Recombined 2 regimes into one program.
          5. Add Preprocessing

          Alternative 4: 83.6% accurate, 22.9× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;n0\_i \leq 1.5000000583807998 \cdot 10^{-16}:\\ \;\;\;\;n1\_i \cdot u + 1 \cdot n0\_i\\ \mathbf{else}:\\ \;\;\;\;n0\_i \cdot \left(1 - u\right)\\ \end{array} \end{array} \]
          (FPCore (normAngle u n0_i n1_i)
           :precision binary32
           (if (<= n0_i 1.5000000583807998e-16)
             (+ (* n1_i u) (* 1.0 n0_i))
             (* n0_i (- 1.0 u))))
          float code(float normAngle, float u, float n0_i, float n1_i) {
          	float tmp;
          	if (n0_i <= 1.5000000583807998e-16f) {
          		tmp = (n1_i * u) + (1.0f * n0_i);
          	} else {
          		tmp = n0_i * (1.0f - u);
          	}
          	return tmp;
          }
          
          real(4) function code(normangle, u, n0_i, n1_i)
              real(4), intent (in) :: normangle
              real(4), intent (in) :: u
              real(4), intent (in) :: n0_i
              real(4), intent (in) :: n1_i
              real(4) :: tmp
              if (n0_i <= 1.5000000583807998e-16) then
                  tmp = (n1_i * u) + (1.0e0 * n0_i)
              else
                  tmp = n0_i * (1.0e0 - u)
              end if
              code = tmp
          end function
          
          function code(normAngle, u, n0_i, n1_i)
          	tmp = Float32(0.0)
          	if (n0_i <= Float32(1.5000000583807998e-16))
          		tmp = Float32(Float32(n1_i * u) + Float32(Float32(1.0) * n0_i));
          	else
          		tmp = Float32(n0_i * Float32(Float32(1.0) - u));
          	end
          	return tmp
          end
          
          function tmp_2 = code(normAngle, u, n0_i, n1_i)
          	tmp = single(0.0);
          	if (n0_i <= single(1.5000000583807998e-16))
          		tmp = (n1_i * u) + (single(1.0) * n0_i);
          	else
          		tmp = n0_i * (single(1.0) - u);
          	end
          	tmp_2 = tmp;
          end
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          \mathbf{if}\;n0\_i \leq 1.5000000583807998 \cdot 10^{-16}:\\
          \;\;\;\;n1\_i \cdot u + 1 \cdot n0\_i\\
          
          \mathbf{else}:\\
          \;\;\;\;n0\_i \cdot \left(1 - u\right)\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if n0_i < 1.5000001e-16

            1. Initial program 96.3%

              \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
            2. Add Preprocessing
            3. Taylor expanded in u around 0

              \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \color{blue}{\frac{normAngle \cdot u}{\sin normAngle}} \cdot n1\_i \]
            4. Step-by-step derivation
              1. associate-*l/N/A

                \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \color{blue}{\left(\frac{normAngle}{\sin normAngle} \cdot u\right)} \cdot n1\_i \]
              2. lower-*.f32N/A

                \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \color{blue}{\left(\frac{normAngle}{\sin normAngle} \cdot u\right)} \cdot n1\_i \]
              3. lower-/.f32N/A

                \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\color{blue}{\frac{normAngle}{\sin normAngle}} \cdot u\right) \cdot n1\_i \]
              4. lower-sin.f3298.2

                \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\frac{normAngle}{\color{blue}{\sin normAngle}} \cdot u\right) \cdot n1\_i \]
            5. Applied rewrites98.2%

              \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \color{blue}{\left(\frac{normAngle}{\sin normAngle} \cdot u\right)} \cdot n1\_i \]
            6. Step-by-step derivation
              1. lift-*.f32N/A

                \[\leadsto \color{blue}{\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right)} \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
              2. lift-/.f32N/A

                \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \color{blue}{\frac{1}{\sin normAngle}}\right) \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
              3. un-div-invN/A

                \[\leadsto \color{blue}{\frac{\sin \left(\left(1 - u\right) \cdot normAngle\right)}{\sin normAngle}} \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
              4. lower-/.f3299.2

                \[\leadsto \color{blue}{\frac{\sin \left(\left(1 - u\right) \cdot normAngle\right)}{\sin normAngle}} \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
              5. lift-*.f32N/A

                \[\leadsto \frac{\sin \color{blue}{\left(\left(1 - u\right) \cdot normAngle\right)}}{\sin normAngle} \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
              6. *-commutativeN/A

                \[\leadsto \frac{\sin \color{blue}{\left(normAngle \cdot \left(1 - u\right)\right)}}{\sin normAngle} \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
              7. lower-*.f3299.2

                \[\leadsto \frac{\sin \color{blue}{\left(normAngle \cdot \left(1 - u\right)\right)}}{\sin normAngle} \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
            7. Applied rewrites99.2%

              \[\leadsto \color{blue}{\frac{\sin \left(normAngle \cdot \left(1 - u\right)\right)}{\sin normAngle}} \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
            8. Taylor expanded in u around 0

              \[\leadsto \color{blue}{1} \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
            9. Step-by-step derivation
              1. Applied rewrites86.1%

                \[\leadsto \color{blue}{1} \cdot n0\_i + \left(\frac{normAngle}{\sin normAngle} \cdot u\right) \cdot n1\_i \]
              2. Taylor expanded in normAngle around 0

                \[\leadsto 1 \cdot n0\_i + \color{blue}{n1\_i \cdot u} \]
              3. Step-by-step derivation
                1. lower-*.f3285.2

                  \[\leadsto 1 \cdot n0\_i + \color{blue}{n1\_i \cdot u} \]
              4. Applied rewrites85.2%

                \[\leadsto 1 \cdot n0\_i + \color{blue}{n1\_i \cdot u} \]

              if 1.5000001e-16 < n0_i

              1. Initial program 99.0%

                \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
              2. Add Preprocessing
              3. Taylor expanded in normAngle around 0

                \[\leadsto \color{blue}{n0\_i \cdot \left(1 - u\right) + n1\_i \cdot u} \]
              4. Step-by-step derivation
                1. *-commutativeN/A

                  \[\leadsto \color{blue}{\left(1 - u\right) \cdot n0\_i} + n1\_i \cdot u \]
                2. lower-fma.f32N/A

                  \[\leadsto \color{blue}{\mathsf{fma}\left(1 - u, n0\_i, n1\_i \cdot u\right)} \]
                3. lower--.f32N/A

                  \[\leadsto \mathsf{fma}\left(\color{blue}{1 - u}, n0\_i, n1\_i \cdot u\right) \]
                4. lower-*.f329.7

                  \[\leadsto \mathsf{fma}\left(1 - u, n0\_i, \color{blue}{n1\_i \cdot u}\right) \]
              5. Applied rewrites9.6%

                \[\leadsto \color{blue}{\mathsf{fma}\left(1 - u, n0\_i, n1\_i \cdot u\right)} \]
              6. Step-by-step derivation
                1. Applied rewrites98.4%

                  \[\leadsto n1\_i \cdot u + \color{blue}{n0\_i \cdot \left(1 - u\right)} \]
                2. Step-by-step derivation
                  1. Applied rewrites98.8%

                    \[\leadsto n1\_i \cdot u + \left(n0\_i + \color{blue}{\left(-u\right) \cdot n0\_i}\right) \]
                  2. Taylor expanded in n0_i around -inf

                    \[\leadsto -1 \cdot \color{blue}{\left(n0\_i \cdot \left(u - 1\right)\right)} \]
                  3. Step-by-step derivation
                    1. Applied rewrites91.0%

                      \[\leadsto n0\_i \cdot \color{blue}{\left(1 - u\right)} \]
                  4. Recombined 2 regimes into one program.
                  5. Final simplification86.5%

                    \[\leadsto \begin{array}{l} \mathbf{if}\;n0\_i \leq 1.5000000583807998 \cdot 10^{-16}:\\ \;\;\;\;n1\_i \cdot u + 1 \cdot n0\_i\\ \mathbf{else}:\\ \;\;\;\;n0\_i \cdot \left(1 - u\right)\\ \end{array} \]
                  6. Add Preprocessing

                  Alternative 5: 97.9% accurate, 27.0× speedup?

                  \[\begin{array}{l} \\ \left(n0\_i - n0\_i \cdot u\right) + n1\_i \cdot u \end{array} \]
                  (FPCore (normAngle u n0_i n1_i)
                   :precision binary32
                   (+ (- n0_i (* n0_i u)) (* n1_i u)))
                  float code(float normAngle, float u, float n0_i, float n1_i) {
                  	return (n0_i - (n0_i * u)) + (n1_i * u);
                  }
                  
                  real(4) function code(normangle, u, n0_i, n1_i)
                      real(4), intent (in) :: normangle
                      real(4), intent (in) :: u
                      real(4), intent (in) :: n0_i
                      real(4), intent (in) :: n1_i
                      code = (n0_i - (n0_i * u)) + (n1_i * u)
                  end function
                  
                  function code(normAngle, u, n0_i, n1_i)
                  	return Float32(Float32(n0_i - Float32(n0_i * u)) + Float32(n1_i * u))
                  end
                  
                  function tmp = code(normAngle, u, n0_i, n1_i)
                  	tmp = (n0_i - (n0_i * u)) + (n1_i * u);
                  end
                  
                  \begin{array}{l}
                  
                  \\
                  \left(n0\_i - n0\_i \cdot u\right) + n1\_i \cdot u
                  \end{array}
                  
                  Derivation
                  1. Initial program 96.9%

                    \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
                  2. Add Preprocessing
                  3. Taylor expanded in normAngle around 0

                    \[\leadsto \color{blue}{n0\_i \cdot \left(1 - u\right) + n1\_i \cdot u} \]
                  4. Step-by-step derivation
                    1. *-commutativeN/A

                      \[\leadsto \color{blue}{\left(1 - u\right) \cdot n0\_i} + n1\_i \cdot u \]
                    2. lower-fma.f32N/A

                      \[\leadsto \color{blue}{\mathsf{fma}\left(1 - u, n0\_i, n1\_i \cdot u\right)} \]
                    3. lower--.f32N/A

                      \[\leadsto \mathsf{fma}\left(\color{blue}{1 - u}, n0\_i, n1\_i \cdot u\right) \]
                    4. lower-*.f3237.7

                      \[\leadsto \mathsf{fma}\left(1 - u, n0\_i, \color{blue}{n1\_i \cdot u}\right) \]
                  5. Applied rewrites37.7%

                    \[\leadsto \color{blue}{\mathsf{fma}\left(1 - u, n0\_i, n1\_i \cdot u\right)} \]
                  6. Step-by-step derivation
                    1. Applied rewrites98.0%

                      \[\leadsto n1\_i \cdot u + \color{blue}{n0\_i \cdot \left(1 - u\right)} \]
                    2. Step-by-step derivation
                      1. Applied rewrites98.2%

                        \[\leadsto n1\_i \cdot u + \left(n0\_i + \color{blue}{\left(-u\right) \cdot n0\_i}\right) \]
                      2. Step-by-step derivation
                        1. Applied rewrites98.2%

                          \[\leadsto n1\_i \cdot u + \left(n0\_i - \color{blue}{n0\_i \cdot u}\right) \]
                        2. Final simplification98.2%

                          \[\leadsto \left(n0\_i - n0\_i \cdot u\right) + n1\_i \cdot u \]
                        3. Add Preprocessing

                        Alternative 6: 97.8% accurate, 27.0× speedup?

                        \[\begin{array}{l} \\ n0\_i \cdot \left(1 - u\right) + n1\_i \cdot u \end{array} \]
                        (FPCore (normAngle u n0_i n1_i)
                         :precision binary32
                         (+ (* n0_i (- 1.0 u)) (* n1_i u)))
                        float code(float normAngle, float u, float n0_i, float n1_i) {
                        	return (n0_i * (1.0f - u)) + (n1_i * u);
                        }
                        
                        real(4) function code(normangle, u, n0_i, n1_i)
                            real(4), intent (in) :: normangle
                            real(4), intent (in) :: u
                            real(4), intent (in) :: n0_i
                            real(4), intent (in) :: n1_i
                            code = (n0_i * (1.0e0 - u)) + (n1_i * u)
                        end function
                        
                        function code(normAngle, u, n0_i, n1_i)
                        	return Float32(Float32(n0_i * Float32(Float32(1.0) - u)) + Float32(n1_i * u))
                        end
                        
                        function tmp = code(normAngle, u, n0_i, n1_i)
                        	tmp = (n0_i * (single(1.0) - u)) + (n1_i * u);
                        end
                        
                        \begin{array}{l}
                        
                        \\
                        n0\_i \cdot \left(1 - u\right) + n1\_i \cdot u
                        \end{array}
                        
                        Derivation
                        1. Initial program 96.9%

                          \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
                        2. Add Preprocessing
                        3. Taylor expanded in normAngle around 0

                          \[\leadsto \color{blue}{n0\_i \cdot \left(1 - u\right) + n1\_i \cdot u} \]
                        4. Step-by-step derivation
                          1. *-commutativeN/A

                            \[\leadsto \color{blue}{\left(1 - u\right) \cdot n0\_i} + n1\_i \cdot u \]
                          2. lower-fma.f32N/A

                            \[\leadsto \color{blue}{\mathsf{fma}\left(1 - u, n0\_i, n1\_i \cdot u\right)} \]
                          3. lower--.f32N/A

                            \[\leadsto \mathsf{fma}\left(\color{blue}{1 - u}, n0\_i, n1\_i \cdot u\right) \]
                          4. lower-*.f3237.7

                            \[\leadsto \mathsf{fma}\left(1 - u, n0\_i, \color{blue}{n1\_i \cdot u}\right) \]
                        5. Applied rewrites37.7%

                          \[\leadsto \color{blue}{\mathsf{fma}\left(1 - u, n0\_i, n1\_i \cdot u\right)} \]
                        6. Step-by-step derivation
                          1. Applied rewrites98.0%

                            \[\leadsto n1\_i \cdot u + \color{blue}{n0\_i \cdot \left(1 - u\right)} \]
                          2. Final simplification98.0%

                            \[\leadsto n0\_i \cdot \left(1 - u\right) + n1\_i \cdot u \]
                          3. Add Preprocessing

                          Alternative 7: 58.1% accurate, 51.0× speedup?

                          \[\begin{array}{l} \\ n0\_i \cdot \left(1 - u\right) \end{array} \]
                          (FPCore (normAngle u n0_i n1_i) :precision binary32 (* n0_i (- 1.0 u)))
                          float code(float normAngle, float u, float n0_i, float n1_i) {
                          	return n0_i * (1.0f - u);
                          }
                          
                          real(4) function code(normangle, u, n0_i, n1_i)
                              real(4), intent (in) :: normangle
                              real(4), intent (in) :: u
                              real(4), intent (in) :: n0_i
                              real(4), intent (in) :: n1_i
                              code = n0_i * (1.0e0 - u)
                          end function
                          
                          function code(normAngle, u, n0_i, n1_i)
                          	return Float32(n0_i * Float32(Float32(1.0) - u))
                          end
                          
                          function tmp = code(normAngle, u, n0_i, n1_i)
                          	tmp = n0_i * (single(1.0) - u);
                          end
                          
                          \begin{array}{l}
                          
                          \\
                          n0\_i \cdot \left(1 - u\right)
                          \end{array}
                          
                          Derivation
                          1. Initial program 96.9%

                            \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
                          2. Add Preprocessing
                          3. Taylor expanded in normAngle around 0

                            \[\leadsto \color{blue}{n0\_i \cdot \left(1 - u\right) + n1\_i \cdot u} \]
                          4. Step-by-step derivation
                            1. *-commutativeN/A

                              \[\leadsto \color{blue}{\left(1 - u\right) \cdot n0\_i} + n1\_i \cdot u \]
                            2. lower-fma.f32N/A

                              \[\leadsto \color{blue}{\mathsf{fma}\left(1 - u, n0\_i, n1\_i \cdot u\right)} \]
                            3. lower--.f32N/A

                              \[\leadsto \mathsf{fma}\left(\color{blue}{1 - u}, n0\_i, n1\_i \cdot u\right) \]
                            4. lower-*.f3237.7

                              \[\leadsto \mathsf{fma}\left(1 - u, n0\_i, \color{blue}{n1\_i \cdot u}\right) \]
                          5. Applied rewrites37.7%

                            \[\leadsto \color{blue}{\mathsf{fma}\left(1 - u, n0\_i, n1\_i \cdot u\right)} \]
                          6. Step-by-step derivation
                            1. Applied rewrites98.0%

                              \[\leadsto n1\_i \cdot u + \color{blue}{n0\_i \cdot \left(1 - u\right)} \]
                            2. Step-by-step derivation
                              1. Applied rewrites98.2%

                                \[\leadsto n1\_i \cdot u + \left(n0\_i + \color{blue}{\left(-u\right) \cdot n0\_i}\right) \]
                              2. Taylor expanded in n0_i around -inf

                                \[\leadsto -1 \cdot \color{blue}{\left(n0\_i \cdot \left(u - 1\right)\right)} \]
                              3. Step-by-step derivation
                                1. Applied rewrites58.6%

                                  \[\leadsto n0\_i \cdot \color{blue}{\left(1 - u\right)} \]
                                2. Add Preprocessing

                                Alternative 8: 7.9% accurate, 57.4× speedup?

                                \[\begin{array}{l} \\ \left(-n0\_i\right) \cdot u \end{array} \]
                                (FPCore (normAngle u n0_i n1_i) :precision binary32 (* (- n0_i) u))
                                float code(float normAngle, float u, float n0_i, float n1_i) {
                                	return -n0_i * u;
                                }
                                
                                real(4) function code(normangle, u, n0_i, n1_i)
                                    real(4), intent (in) :: normangle
                                    real(4), intent (in) :: u
                                    real(4), intent (in) :: n0_i
                                    real(4), intent (in) :: n1_i
                                    code = -n0_i * u
                                end function
                                
                                function code(normAngle, u, n0_i, n1_i)
                                	return Float32(Float32(-n0_i) * u)
                                end
                                
                                function tmp = code(normAngle, u, n0_i, n1_i)
                                	tmp = -n0_i * u;
                                end
                                
                                \begin{array}{l}
                                
                                \\
                                \left(-n0\_i\right) \cdot u
                                \end{array}
                                
                                Derivation
                                1. Initial program 96.9%

                                  \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
                                2. Add Preprocessing
                                3. Taylor expanded in normAngle around 0

                                  \[\leadsto \color{blue}{n0\_i \cdot \left(1 - u\right) + n1\_i \cdot u} \]
                                4. Step-by-step derivation
                                  1. *-commutativeN/A

                                    \[\leadsto \color{blue}{\left(1 - u\right) \cdot n0\_i} + n1\_i \cdot u \]
                                  2. lower-fma.f32N/A

                                    \[\leadsto \color{blue}{\mathsf{fma}\left(1 - u, n0\_i, n1\_i \cdot u\right)} \]
                                  3. lower--.f32N/A

                                    \[\leadsto \mathsf{fma}\left(\color{blue}{1 - u}, n0\_i, n1\_i \cdot u\right) \]
                                  4. lower-*.f3237.7

                                    \[\leadsto \mathsf{fma}\left(1 - u, n0\_i, \color{blue}{n1\_i \cdot u}\right) \]
                                5. Applied rewrites37.7%

                                  \[\leadsto \color{blue}{\mathsf{fma}\left(1 - u, n0\_i, n1\_i \cdot u\right)} \]
                                6. Taylor expanded in u around inf

                                  \[\leadsto u \cdot \color{blue}{\left(n1\_i + -1 \cdot n0\_i\right)} \]
                                7. Step-by-step derivation
                                  1. Applied rewrites36.1%

                                    \[\leadsto \left(n1\_i - n0\_i\right) \cdot \color{blue}{u} \]
                                  2. Taylor expanded in n0_i around inf

                                    \[\leadsto \left(-1 \cdot n0\_i\right) \cdot u \]
                                  3. Step-by-step derivation
                                    1. Applied rewrites7.4%

                                      \[\leadsto \left(-n0\_i\right) \cdot u \]
                                    2. Add Preprocessing

                                    Reproduce

                                    ?
                                    herbie shell --seed 2024304 
                                    (FPCore (normAngle u n0_i n1_i)
                                      :name "Curve intersection, scale width based on ribbon orientation"
                                      :precision binary32
                                      :pre (and (and (and (and (<= 0.0 normAngle) (<= normAngle (/ (PI) 2.0))) (and (<= -1.0 n0_i) (<= n0_i 1.0))) (and (<= -1.0 n1_i) (<= n1_i 1.0))) (and (<= 2.328306437e-10 u) (<= u 1.0)))
                                      (+ (* (* (sin (* (- 1.0 u) normAngle)) (/ 1.0 (sin normAngle))) n0_i) (* (* (sin (* u normAngle)) (/ 1.0 (sin normAngle))) n1_i)))