
(FPCore (x y z t a) :precision binary64 (+ x (/ (* y (- z t)) a)))
double code(double x, double y, double z, double t, double a) {
return x + ((y * (z - t)) / a);
}
real(8) function code(x, y, z, t, a)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8), intent (in) :: t
real(8), intent (in) :: a
code = x + ((y * (z - t)) / a)
end function
public static double code(double x, double y, double z, double t, double a) {
return x + ((y * (z - t)) / a);
}
def code(x, y, z, t, a): return x + ((y * (z - t)) / a)
function code(x, y, z, t, a) return Float64(x + Float64(Float64(y * Float64(z - t)) / a)) end
function tmp = code(x, y, z, t, a) tmp = x + ((y * (z - t)) / a); end
code[x_, y_, z_, t_, a_] := N[(x + N[(N[(y * N[(z - t), $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + \frac{y \cdot \left(z - t\right)}{a}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 10 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y z t a) :precision binary64 (+ x (/ (* y (- z t)) a)))
double code(double x, double y, double z, double t, double a) {
return x + ((y * (z - t)) / a);
}
real(8) function code(x, y, z, t, a)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8), intent (in) :: t
real(8), intent (in) :: a
code = x + ((y * (z - t)) / a)
end function
public static double code(double x, double y, double z, double t, double a) {
return x + ((y * (z - t)) / a);
}
def code(x, y, z, t, a): return x + ((y * (z - t)) / a)
function code(x, y, z, t, a) return Float64(x + Float64(Float64(y * Float64(z - t)) / a)) end
function tmp = code(x, y, z, t, a) tmp = x + ((y * (z - t)) / a); end
code[x_, y_, z_, t_, a_] := N[(x + N[(N[(y * N[(z - t), $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + \frac{y \cdot \left(z - t\right)}{a}
\end{array}
(FPCore (x y z t a) :precision binary64 (let* ((t_1 (* y (- z t))) (t_2 (fma (/ y a) (- z t) x))) (if (<= t_1 -5e+245) t_2 (if (<= t_1 2e+103) (+ (/ t_1 a) x) t_2))))
double code(double x, double y, double z, double t, double a) {
double t_1 = y * (z - t);
double t_2 = fma((y / a), (z - t), x);
double tmp;
if (t_1 <= -5e+245) {
tmp = t_2;
} else if (t_1 <= 2e+103) {
tmp = (t_1 / a) + x;
} else {
tmp = t_2;
}
return tmp;
}
function code(x, y, z, t, a) t_1 = Float64(y * Float64(z - t)) t_2 = fma(Float64(y / a), Float64(z - t), x) tmp = 0.0 if (t_1 <= -5e+245) tmp = t_2; elseif (t_1 <= 2e+103) tmp = Float64(Float64(t_1 / a) + x); else tmp = t_2; end return tmp end
code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(y * N[(z - t), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(y / a), $MachinePrecision] * N[(z - t), $MachinePrecision] + x), $MachinePrecision]}, If[LessEqual[t$95$1, -5e+245], t$95$2, If[LessEqual[t$95$1, 2e+103], N[(N[(t$95$1 / a), $MachinePrecision] + x), $MachinePrecision], t$95$2]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := y \cdot \left(z - t\right)\\
t_2 := \mathsf{fma}\left(\frac{y}{a}, z - t, x\right)\\
\mathbf{if}\;t\_1 \leq -5 \cdot 10^{+245}:\\
\;\;\;\;t\_2\\
\mathbf{elif}\;t\_1 \leq 2 \cdot 10^{+103}:\\
\;\;\;\;\frac{t\_1}{a} + x\\
\mathbf{else}:\\
\;\;\;\;t\_2\\
\end{array}
\end{array}
if (*.f64 y (-.f64 z t)) < -5.00000000000000034e245 or 2e103 < (*.f64 y (-.f64 z t)) Initial program 79.2%
lift-+.f64N/A
+-commutativeN/A
lift-/.f64N/A
lift-*.f64N/A
*-commutativeN/A
associate-/l*N/A
*-commutativeN/A
lower-fma.f64N/A
lower-/.f6499.8
Applied rewrites99.8%
if -5.00000000000000034e245 < (*.f64 y (-.f64 z t)) < 2e103Initial program 99.9%
Final simplification99.9%
(FPCore (x y z t a) :precision binary64 (let* ((t_1 (/ (* y (- z t)) a))) (if (<= t_1 -1e+162) t_1 (if (<= t_1 5e+74) (fma (/ z a) y x) t_1))))
double code(double x, double y, double z, double t, double a) {
double t_1 = (y * (z - t)) / a;
double tmp;
if (t_1 <= -1e+162) {
tmp = t_1;
} else if (t_1 <= 5e+74) {
tmp = fma((z / a), y, x);
} else {
tmp = t_1;
}
return tmp;
}
function code(x, y, z, t, a) t_1 = Float64(Float64(y * Float64(z - t)) / a) tmp = 0.0 if (t_1 <= -1e+162) tmp = t_1; elseif (t_1 <= 5e+74) tmp = fma(Float64(z / a), y, x); else tmp = t_1; end return tmp end
code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[(y * N[(z - t), $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision]}, If[LessEqual[t$95$1, -1e+162], t$95$1, If[LessEqual[t$95$1, 5e+74], N[(N[(z / a), $MachinePrecision] * y + x), $MachinePrecision], t$95$1]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \frac{y \cdot \left(z - t\right)}{a}\\
\mathbf{if}\;t\_1 \leq -1 \cdot 10^{+162}:\\
\;\;\;\;t\_1\\
\mathbf{elif}\;t\_1 \leq 5 \cdot 10^{+74}:\\
\;\;\;\;\mathsf{fma}\left(\frac{z}{a}, y, x\right)\\
\mathbf{else}:\\
\;\;\;\;t\_1\\
\end{array}
\end{array}
if (/.f64 (*.f64 y (-.f64 z t)) a) < -9.9999999999999994e161 or 4.99999999999999963e74 < (/.f64 (*.f64 y (-.f64 z t)) a) Initial program 83.6%
Taylor expanded in a around 0
lower-/.f64N/A
*-commutativeN/A
lower-*.f64N/A
lower--.f6478.0
Applied rewrites78.0%
if -9.9999999999999994e161 < (/.f64 (*.f64 y (-.f64 z t)) a) < 4.99999999999999963e74Initial program 99.9%
Taylor expanded in t around 0
+-commutativeN/A
associate-/l*N/A
*-commutativeN/A
lower-fma.f64N/A
lower-/.f6485.7
Applied rewrites85.7%
Final simplification81.6%
(FPCore (x y z t a) :precision binary64 (if (<= (- z t) -4e+78) (fma (/ y a) (- z t) x) (+ (/ y (/ a (- z t))) x)))
double code(double x, double y, double z, double t, double a) {
double tmp;
if ((z - t) <= -4e+78) {
tmp = fma((y / a), (z - t), x);
} else {
tmp = (y / (a / (z - t))) + x;
}
return tmp;
}
function code(x, y, z, t, a) tmp = 0.0 if (Float64(z - t) <= -4e+78) tmp = fma(Float64(y / a), Float64(z - t), x); else tmp = Float64(Float64(y / Float64(a / Float64(z - t))) + x); end return tmp end
code[x_, y_, z_, t_, a_] := If[LessEqual[N[(z - t), $MachinePrecision], -4e+78], N[(N[(y / a), $MachinePrecision] * N[(z - t), $MachinePrecision] + x), $MachinePrecision], N[(N[(y / N[(a / N[(z - t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + x), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z - t \leq -4 \cdot 10^{+78}:\\
\;\;\;\;\mathsf{fma}\left(\frac{y}{a}, z - t, x\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{y}{\frac{a}{z - t}} + x\\
\end{array}
\end{array}
if (-.f64 z t) < -4.00000000000000003e78Initial program 84.3%
lift-+.f64N/A
+-commutativeN/A
lift-/.f64N/A
lift-*.f64N/A
*-commutativeN/A
associate-/l*N/A
*-commutativeN/A
lower-fma.f64N/A
lower-/.f6497.4
Applied rewrites97.4%
if -4.00000000000000003e78 < (-.f64 z t) Initial program 94.1%
lift-/.f64N/A
lift-*.f64N/A
associate-/l*N/A
clear-numN/A
un-div-invN/A
lower-/.f64N/A
lower-/.f6499.0
Applied rewrites99.0%
Final simplification98.5%
(FPCore (x y z t a) :precision binary64 (let* ((t_1 (fma (/ y a) (- t) x))) (if (<= t -6.4e+78) t_1 (if (<= t 9.5e+36) (fma (/ z a) y x) t_1))))
double code(double x, double y, double z, double t, double a) {
double t_1 = fma((y / a), -t, x);
double tmp;
if (t <= -6.4e+78) {
tmp = t_1;
} else if (t <= 9.5e+36) {
tmp = fma((z / a), y, x);
} else {
tmp = t_1;
}
return tmp;
}
function code(x, y, z, t, a) t_1 = fma(Float64(y / a), Float64(-t), x) tmp = 0.0 if (t <= -6.4e+78) tmp = t_1; elseif (t <= 9.5e+36) tmp = fma(Float64(z / a), y, x); else tmp = t_1; end return tmp end
code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[(y / a), $MachinePrecision] * (-t) + x), $MachinePrecision]}, If[LessEqual[t, -6.4e+78], t$95$1, If[LessEqual[t, 9.5e+36], N[(N[(z / a), $MachinePrecision] * y + x), $MachinePrecision], t$95$1]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \mathsf{fma}\left(\frac{y}{a}, -t, x\right)\\
\mathbf{if}\;t \leq -6.4 \cdot 10^{+78}:\\
\;\;\;\;t\_1\\
\mathbf{elif}\;t \leq 9.5 \cdot 10^{+36}:\\
\;\;\;\;\mathsf{fma}\left(\frac{z}{a}, y, x\right)\\
\mathbf{else}:\\
\;\;\;\;t\_1\\
\end{array}
\end{array}
if t < -6.39999999999999989e78 or 9.49999999999999974e36 < t Initial program 85.0%
Taylor expanded in z around 0
+-commutativeN/A
*-commutativeN/A
associate-*l/N/A
associate-*l*N/A
*-commutativeN/A
associate-*l*N/A
lower-fma.f64N/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6489.6
Applied rewrites89.6%
if -6.39999999999999989e78 < t < 9.49999999999999974e36Initial program 95.6%
Taylor expanded in t around 0
+-commutativeN/A
associate-/l*N/A
*-commutativeN/A
lower-fma.f64N/A
lower-/.f6487.7
Applied rewrites87.7%
(FPCore (x y z t a) :precision binary64 (let* ((t_1 (* (/ (- y) a) t))) (if (<= t -1.85e+126) t_1 (if (<= t 7.5e+112) (fma (/ y a) z x) t_1))))
double code(double x, double y, double z, double t, double a) {
double t_1 = (-y / a) * t;
double tmp;
if (t <= -1.85e+126) {
tmp = t_1;
} else if (t <= 7.5e+112) {
tmp = fma((y / a), z, x);
} else {
tmp = t_1;
}
return tmp;
}
function code(x, y, z, t, a) t_1 = Float64(Float64(Float64(-y) / a) * t) tmp = 0.0 if (t <= -1.85e+126) tmp = t_1; elseif (t <= 7.5e+112) tmp = fma(Float64(y / a), z, x); else tmp = t_1; end return tmp end
code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[((-y) / a), $MachinePrecision] * t), $MachinePrecision]}, If[LessEqual[t, -1.85e+126], t$95$1, If[LessEqual[t, 7.5e+112], N[(N[(y / a), $MachinePrecision] * z + x), $MachinePrecision], t$95$1]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \frac{-y}{a} \cdot t\\
\mathbf{if}\;t \leq -1.85 \cdot 10^{+126}:\\
\;\;\;\;t\_1\\
\mathbf{elif}\;t \leq 7.5 \cdot 10^{+112}:\\
\;\;\;\;\mathsf{fma}\left(\frac{y}{a}, z, x\right)\\
\mathbf{else}:\\
\;\;\;\;t\_1\\
\end{array}
\end{array}
if t < -1.8499999999999999e126 or 7.5e112 < t Initial program 81.8%
Taylor expanded in t around inf
mul-1-negN/A
associate-*l/N/A
distribute-lft-neg-outN/A
lower-*.f64N/A
distribute-neg-fracN/A
mul-1-negN/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6467.0
Applied rewrites67.0%
Applied rewrites73.6%
if -1.8499999999999999e126 < t < 7.5e112Initial program 95.6%
lift-*.f64N/A
lift--.f64N/A
sub-negN/A
+-commutativeN/A
distribute-rgt-inN/A
lower-fma.f64N/A
lower-neg.f64N/A
lower-*.f6495.6
Applied rewrites95.6%
Taylor expanded in t around 0
+-commutativeN/A
associate-*l/N/A
lower-fma.f64N/A
lower-/.f6484.6
Applied rewrites84.6%
(FPCore (x y z t a) :precision binary64 (let* ((t_1 (* (/ (- t) a) y))) (if (<= t -1.75e+126) t_1 (if (<= t 7.5e+112) (fma (/ y a) z x) t_1))))
double code(double x, double y, double z, double t, double a) {
double t_1 = (-t / a) * y;
double tmp;
if (t <= -1.75e+126) {
tmp = t_1;
} else if (t <= 7.5e+112) {
tmp = fma((y / a), z, x);
} else {
tmp = t_1;
}
return tmp;
}
function code(x, y, z, t, a) t_1 = Float64(Float64(Float64(-t) / a) * y) tmp = 0.0 if (t <= -1.75e+126) tmp = t_1; elseif (t <= 7.5e+112) tmp = fma(Float64(y / a), z, x); else tmp = t_1; end return tmp end
code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[((-t) / a), $MachinePrecision] * y), $MachinePrecision]}, If[LessEqual[t, -1.75e+126], t$95$1, If[LessEqual[t, 7.5e+112], N[(N[(y / a), $MachinePrecision] * z + x), $MachinePrecision], t$95$1]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \frac{-t}{a} \cdot y\\
\mathbf{if}\;t \leq -1.75 \cdot 10^{+126}:\\
\;\;\;\;t\_1\\
\mathbf{elif}\;t \leq 7.5 \cdot 10^{+112}:\\
\;\;\;\;\mathsf{fma}\left(\frac{y}{a}, z, x\right)\\
\mathbf{else}:\\
\;\;\;\;t\_1\\
\end{array}
\end{array}
if t < -1.7500000000000001e126 or 7.5e112 < t Initial program 81.8%
Taylor expanded in t around inf
mul-1-negN/A
associate-*l/N/A
distribute-lft-neg-outN/A
lower-*.f64N/A
distribute-neg-fracN/A
mul-1-negN/A
lower-/.f64N/A
mul-1-negN/A
lower-neg.f6467.0
Applied rewrites67.0%
if -1.7500000000000001e126 < t < 7.5e112Initial program 95.6%
lift-*.f64N/A
lift--.f64N/A
sub-negN/A
+-commutativeN/A
distribute-rgt-inN/A
lower-fma.f64N/A
lower-neg.f64N/A
lower-*.f6495.6
Applied rewrites95.6%
Taylor expanded in t around 0
+-commutativeN/A
associate-*l/N/A
lower-fma.f64N/A
lower-/.f6484.6
Applied rewrites84.6%
(FPCore (x y z t a) :precision binary64 (fma (/ y a) (- z t) x))
double code(double x, double y, double z, double t, double a) {
return fma((y / a), (z - t), x);
}
function code(x, y, z, t, a) return fma(Float64(y / a), Float64(z - t), x) end
code[x_, y_, z_, t_, a_] := N[(N[(y / a), $MachinePrecision] * N[(z - t), $MachinePrecision] + x), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\frac{y}{a}, z - t, x\right)
\end{array}
Initial program 91.2%
lift-+.f64N/A
+-commutativeN/A
lift-/.f64N/A
lift-*.f64N/A
*-commutativeN/A
associate-/l*N/A
*-commutativeN/A
lower-fma.f64N/A
lower-/.f6496.0
Applied rewrites96.0%
(FPCore (x y z t a) :precision binary64 (fma (/ y a) z x))
double code(double x, double y, double z, double t, double a) {
return fma((y / a), z, x);
}
function code(x, y, z, t, a) return fma(Float64(y / a), z, x) end
code[x_, y_, z_, t_, a_] := N[(N[(y / a), $MachinePrecision] * z + x), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\frac{y}{a}, z, x\right)
\end{array}
Initial program 91.2%
lift-*.f64N/A
lift--.f64N/A
sub-negN/A
+-commutativeN/A
distribute-rgt-inN/A
lower-fma.f64N/A
lower-neg.f64N/A
lower-*.f6490.7
Applied rewrites90.7%
Taylor expanded in t around 0
+-commutativeN/A
associate-*l/N/A
lower-fma.f64N/A
lower-/.f6468.4
Applied rewrites68.4%
(FPCore (x y z t a) :precision binary64 (fma (/ z a) y x))
double code(double x, double y, double z, double t, double a) {
return fma((z / a), y, x);
}
function code(x, y, z, t, a) return fma(Float64(z / a), y, x) end
code[x_, y_, z_, t_, a_] := N[(N[(z / a), $MachinePrecision] * y + x), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\frac{z}{a}, y, x\right)
\end{array}
Initial program 91.2%
Taylor expanded in t around 0
+-commutativeN/A
associate-/l*N/A
*-commutativeN/A
lower-fma.f64N/A
lower-/.f6467.4
Applied rewrites67.4%
(FPCore (x y z t a) :precision binary64 (* (/ y a) z))
double code(double x, double y, double z, double t, double a) {
return (y / a) * z;
}
real(8) function code(x, y, z, t, a)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8), intent (in) :: t
real(8), intent (in) :: a
code = (y / a) * z
end function
public static double code(double x, double y, double z, double t, double a) {
return (y / a) * z;
}
def code(x, y, z, t, a): return (y / a) * z
function code(x, y, z, t, a) return Float64(Float64(y / a) * z) end
function tmp = code(x, y, z, t, a) tmp = (y / a) * z; end
code[x_, y_, z_, t_, a_] := N[(N[(y / a), $MachinePrecision] * z), $MachinePrecision]
\begin{array}{l}
\\
\frac{y}{a} \cdot z
\end{array}
Initial program 91.2%
Taylor expanded in z around inf
lower-/.f64N/A
*-commutativeN/A
lower-*.f6432.1
Applied rewrites32.1%
Applied rewrites33.7%
(FPCore (x y z t a)
:precision binary64
(let* ((t_1 (/ a (- z t))))
(if (< y -1.0761266216389975e-10)
(+ x (/ 1.0 (/ t_1 y)))
(if (< y 2.894426862792089e-49)
(+ x (/ (* y (- z t)) a))
(+ x (/ y t_1))))))
double code(double x, double y, double z, double t, double a) {
double t_1 = a / (z - t);
double tmp;
if (y < -1.0761266216389975e-10) {
tmp = x + (1.0 / (t_1 / y));
} else if (y < 2.894426862792089e-49) {
tmp = x + ((y * (z - t)) / a);
} else {
tmp = x + (y / t_1);
}
return tmp;
}
real(8) function code(x, y, z, t, a)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8), intent (in) :: t
real(8), intent (in) :: a
real(8) :: t_1
real(8) :: tmp
t_1 = a / (z - t)
if (y < (-1.0761266216389975d-10)) then
tmp = x + (1.0d0 / (t_1 / y))
else if (y < 2.894426862792089d-49) then
tmp = x + ((y * (z - t)) / a)
else
tmp = x + (y / t_1)
end if
code = tmp
end function
public static double code(double x, double y, double z, double t, double a) {
double t_1 = a / (z - t);
double tmp;
if (y < -1.0761266216389975e-10) {
tmp = x + (1.0 / (t_1 / y));
} else if (y < 2.894426862792089e-49) {
tmp = x + ((y * (z - t)) / a);
} else {
tmp = x + (y / t_1);
}
return tmp;
}
def code(x, y, z, t, a): t_1 = a / (z - t) tmp = 0 if y < -1.0761266216389975e-10: tmp = x + (1.0 / (t_1 / y)) elif y < 2.894426862792089e-49: tmp = x + ((y * (z - t)) / a) else: tmp = x + (y / t_1) return tmp
function code(x, y, z, t, a) t_1 = Float64(a / Float64(z - t)) tmp = 0.0 if (y < -1.0761266216389975e-10) tmp = Float64(x + Float64(1.0 / Float64(t_1 / y))); elseif (y < 2.894426862792089e-49) tmp = Float64(x + Float64(Float64(y * Float64(z - t)) / a)); else tmp = Float64(x + Float64(y / t_1)); end return tmp end
function tmp_2 = code(x, y, z, t, a) t_1 = a / (z - t); tmp = 0.0; if (y < -1.0761266216389975e-10) tmp = x + (1.0 / (t_1 / y)); elseif (y < 2.894426862792089e-49) tmp = x + ((y * (z - t)) / a); else tmp = x + (y / t_1); end tmp_2 = tmp; end
code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(a / N[(z - t), $MachinePrecision]), $MachinePrecision]}, If[Less[y, -1.0761266216389975e-10], N[(x + N[(1.0 / N[(t$95$1 / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[Less[y, 2.894426862792089e-49], N[(x + N[(N[(y * N[(z - t), $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision], N[(x + N[(y / t$95$1), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \frac{a}{z - t}\\
\mathbf{if}\;y < -1.0761266216389975 \cdot 10^{-10}:\\
\;\;\;\;x + \frac{1}{\frac{t\_1}{y}}\\
\mathbf{elif}\;y < 2.894426862792089 \cdot 10^{-49}:\\
\;\;\;\;x + \frac{y \cdot \left(z - t\right)}{a}\\
\mathbf{else}:\\
\;\;\;\;x + \frac{y}{t\_1}\\
\end{array}
\end{array}
herbie shell --seed 2024250
(FPCore (x y z t a)
:name "Optimisation.CirclePacking:place from circle-packing-0.1.0.4, E"
:precision binary64
:alt
(! :herbie-platform default (if (< y -430450648655599/4000000000000000000000000) (+ x (/ 1 (/ (/ a (- z t)) y))) (if (< y 2894426862792089/10000000000000000000000000000000000000000000000000000000000000000) (+ x (/ (* y (- z t)) a)) (+ x (/ y (/ a (- z t)))))))
(+ x (/ (* y (- z t)) a)))