
(FPCore (x y z t a) :precision binary64 (+ x (* y (/ (- z t) (- a t)))))
double code(double x, double y, double z, double t, double a) {
return x + (y * ((z - t) / (a - t)));
}
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 - t)))
end function
public static double code(double x, double y, double z, double t, double a) {
return x + (y * ((z - t) / (a - t)));
}
def code(x, y, z, t, a): return x + (y * ((z - t) / (a - t)))
function code(x, y, z, t, a) return Float64(x + Float64(y * Float64(Float64(z - t) / Float64(a - t)))) end
function tmp = code(x, y, z, t, a) tmp = x + (y * ((z - t) / (a - t))); end
code[x_, y_, z_, t_, a_] := N[(x + N[(y * N[(N[(z - t), $MachinePrecision] / N[(a - t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + y \cdot \frac{z - t}{a - t}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 7 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y z t a) :precision binary64 (+ x (* y (/ (- z t) (- a t)))))
double code(double x, double y, double z, double t, double a) {
return x + (y * ((z - t) / (a - t)));
}
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 - t)))
end function
public static double code(double x, double y, double z, double t, double a) {
return x + (y * ((z - t) / (a - t)));
}
def code(x, y, z, t, a): return x + (y * ((z - t) / (a - t)))
function code(x, y, z, t, a) return Float64(x + Float64(y * Float64(Float64(z - t) / Float64(a - t)))) end
function tmp = code(x, y, z, t, a) tmp = x + (y * ((z - t) / (a - t))); end
code[x_, y_, z_, t_, a_] := N[(x + N[(y * N[(N[(z - t), $MachinePrecision] / N[(a - t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + y \cdot \frac{z - t}{a - t}
\end{array}
(FPCore (x y z t a) :precision binary64 (+ x (* y (/ (- z t) (- a t)))))
double code(double x, double y, double z, double t, double a) {
return x + (y * ((z - t) / (a - t)));
}
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 - t)))
end function
public static double code(double x, double y, double z, double t, double a) {
return x + (y * ((z - t) / (a - t)));
}
def code(x, y, z, t, a): return x + (y * ((z - t) / (a - t)))
function code(x, y, z, t, a) return Float64(x + Float64(y * Float64(Float64(z - t) / Float64(a - t)))) end
function tmp = code(x, y, z, t, a) tmp = x + (y * ((z - t) / (a - t))); end
code[x_, y_, z_, t_, a_] := N[(x + N[(y * N[(N[(z - t), $MachinePrecision] / N[(a - t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + y \cdot \frac{z - t}{a - t}
\end{array}
Initial program 98.4%
(FPCore (x y z t a) :precision binary64 (if (or (<= z -7e+124) (not (<= z 230000000000.0))) (+ x (* z (/ y (- a t)))) (+ x (* y (/ t (- t a))))))
double code(double x, double y, double z, double t, double a) {
double tmp;
if ((z <= -7e+124) || !(z <= 230000000000.0)) {
tmp = x + (z * (y / (a - t)));
} else {
tmp = x + (y * (t / (t - a)));
}
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) :: tmp
if ((z <= (-7d+124)) .or. (.not. (z <= 230000000000.0d0))) then
tmp = x + (z * (y / (a - t)))
else
tmp = x + (y * (t / (t - a)))
end if
code = tmp
end function
public static double code(double x, double y, double z, double t, double a) {
double tmp;
if ((z <= -7e+124) || !(z <= 230000000000.0)) {
tmp = x + (z * (y / (a - t)));
} else {
tmp = x + (y * (t / (t - a)));
}
return tmp;
}
def code(x, y, z, t, a): tmp = 0 if (z <= -7e+124) or not (z <= 230000000000.0): tmp = x + (z * (y / (a - t))) else: tmp = x + (y * (t / (t - a))) return tmp
function code(x, y, z, t, a) tmp = 0.0 if ((z <= -7e+124) || !(z <= 230000000000.0)) tmp = Float64(x + Float64(z * Float64(y / Float64(a - t)))); else tmp = Float64(x + Float64(y * Float64(t / Float64(t - a)))); end return tmp end
function tmp_2 = code(x, y, z, t, a) tmp = 0.0; if ((z <= -7e+124) || ~((z <= 230000000000.0))) tmp = x + (z * (y / (a - t))); else tmp = x + (y * (t / (t - a))); end tmp_2 = tmp; end
code[x_, y_, z_, t_, a_] := If[Or[LessEqual[z, -7e+124], N[Not[LessEqual[z, 230000000000.0]], $MachinePrecision]], N[(x + N[(z * N[(y / N[(a - t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x + N[(y * N[(t / N[(t - a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -7 \cdot 10^{+124} \lor \neg \left(z \leq 230000000000\right):\\
\;\;\;\;x + z \cdot \frac{y}{a - t}\\
\mathbf{else}:\\
\;\;\;\;x + y \cdot \frac{t}{t - a}\\
\end{array}
\end{array}
if z < -7.0000000000000002e124 or 2.3e11 < z Initial program 95.7%
Taylor expanded in z around inf 78.8%
div-inv78.8%
*-commutative78.8%
associate-*l*91.9%
div-inv92.0%
Applied egg-rr92.0%
if -7.0000000000000002e124 < z < 2.3e11Initial program 99.9%
+-commutative99.9%
fma-define99.9%
Simplified99.9%
Taylor expanded in z around 0 77.7%
+-commutative77.7%
associate-*r/77.7%
mul-1-neg77.7%
distribute-lft-neg-out77.7%
*-commutative77.7%
*-lft-identity77.7%
times-frac89.4%
/-rgt-identity89.4%
distribute-neg-frac89.4%
distribute-neg-frac289.4%
neg-sub089.4%
sub-neg89.4%
+-commutative89.4%
associate--r+89.4%
neg-sub089.4%
remove-double-neg89.4%
Simplified89.4%
Final simplification90.4%
(FPCore (x y z t a) :precision binary64 (if (or (<= z -1.1e+125) (not (<= z 3.5e+16))) (+ x (* z (/ y (- a t)))) (+ x (/ y (- 1.0 (/ a t))))))
double code(double x, double y, double z, double t, double a) {
double tmp;
if ((z <= -1.1e+125) || !(z <= 3.5e+16)) {
tmp = x + (z * (y / (a - t)));
} else {
tmp = x + (y / (1.0 - (a / t)));
}
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) :: tmp
if ((z <= (-1.1d+125)) .or. (.not. (z <= 3.5d+16))) then
tmp = x + (z * (y / (a - t)))
else
tmp = x + (y / (1.0d0 - (a / t)))
end if
code = tmp
end function
public static double code(double x, double y, double z, double t, double a) {
double tmp;
if ((z <= -1.1e+125) || !(z <= 3.5e+16)) {
tmp = x + (z * (y / (a - t)));
} else {
tmp = x + (y / (1.0 - (a / t)));
}
return tmp;
}
def code(x, y, z, t, a): tmp = 0 if (z <= -1.1e+125) or not (z <= 3.5e+16): tmp = x + (z * (y / (a - t))) else: tmp = x + (y / (1.0 - (a / t))) return tmp
function code(x, y, z, t, a) tmp = 0.0 if ((z <= -1.1e+125) || !(z <= 3.5e+16)) tmp = Float64(x + Float64(z * Float64(y / Float64(a - t)))); else tmp = Float64(x + Float64(y / Float64(1.0 - Float64(a / t)))); end return tmp end
function tmp_2 = code(x, y, z, t, a) tmp = 0.0; if ((z <= -1.1e+125) || ~((z <= 3.5e+16))) tmp = x + (z * (y / (a - t))); else tmp = x + (y / (1.0 - (a / t))); end tmp_2 = tmp; end
code[x_, y_, z_, t_, a_] := If[Or[LessEqual[z, -1.1e+125], N[Not[LessEqual[z, 3.5e+16]], $MachinePrecision]], N[(x + N[(z * N[(y / N[(a - t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x + N[(y / N[(1.0 - N[(a / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -1.1 \cdot 10^{+125} \lor \neg \left(z \leq 3.5 \cdot 10^{+16}\right):\\
\;\;\;\;x + z \cdot \frac{y}{a - t}\\
\mathbf{else}:\\
\;\;\;\;x + \frac{y}{1 - \frac{a}{t}}\\
\end{array}
\end{array}
if z < -1.09999999999999995e125 or 3.5e16 < z Initial program 95.7%
Taylor expanded in z around inf 78.8%
div-inv78.8%
*-commutative78.8%
associate-*l*91.9%
div-inv92.0%
Applied egg-rr92.0%
if -1.09999999999999995e125 < z < 3.5e16Initial program 99.9%
clear-num99.9%
un-div-inv99.9%
Applied egg-rr99.9%
Taylor expanded in z around 0 77.7%
mul-1-neg77.7%
associate-/l*86.5%
distribute-lft-neg-out86.5%
*-commutative86.5%
distribute-rgt-neg-out86.5%
distribute-lft-neg-in86.5%
distribute-neg-frac286.5%
sub-neg86.5%
distribute-neg-in86.5%
remove-double-neg86.5%
+-commutative86.5%
sub-neg86.5%
associate-/r/89.4%
div-sub89.4%
*-inverses89.4%
Simplified89.4%
Final simplification90.3%
(FPCore (x y z t a) :precision binary64 (if (or (<= t -9.5e+129) (not (<= t 8.4e-75))) (+ x y) (+ x (* z (/ y (- a t))))))
double code(double x, double y, double z, double t, double a) {
double tmp;
if ((t <= -9.5e+129) || !(t <= 8.4e-75)) {
tmp = x + y;
} else {
tmp = x + (z * (y / (a - t)));
}
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) :: tmp
if ((t <= (-9.5d+129)) .or. (.not. (t <= 8.4d-75))) then
tmp = x + y
else
tmp = x + (z * (y / (a - t)))
end if
code = tmp
end function
public static double code(double x, double y, double z, double t, double a) {
double tmp;
if ((t <= -9.5e+129) || !(t <= 8.4e-75)) {
tmp = x + y;
} else {
tmp = x + (z * (y / (a - t)));
}
return tmp;
}
def code(x, y, z, t, a): tmp = 0 if (t <= -9.5e+129) or not (t <= 8.4e-75): tmp = x + y else: tmp = x + (z * (y / (a - t))) return tmp
function code(x, y, z, t, a) tmp = 0.0 if ((t <= -9.5e+129) || !(t <= 8.4e-75)) tmp = Float64(x + y); else tmp = Float64(x + Float64(z * Float64(y / Float64(a - t)))); end return tmp end
function tmp_2 = code(x, y, z, t, a) tmp = 0.0; if ((t <= -9.5e+129) || ~((t <= 8.4e-75))) tmp = x + y; else tmp = x + (z * (y / (a - t))); end tmp_2 = tmp; end
code[x_, y_, z_, t_, a_] := If[Or[LessEqual[t, -9.5e+129], N[Not[LessEqual[t, 8.4e-75]], $MachinePrecision]], N[(x + y), $MachinePrecision], N[(x + N[(z * N[(y / N[(a - t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;t \leq -9.5 \cdot 10^{+129} \lor \neg \left(t \leq 8.4 \cdot 10^{-75}\right):\\
\;\;\;\;x + y\\
\mathbf{else}:\\
\;\;\;\;x + z \cdot \frac{y}{a - t}\\
\end{array}
\end{array}
if t < -9.5000000000000004e129 or 8.4000000000000004e-75 < t Initial program 100.0%
+-commutative100.0%
fma-define100.0%
Simplified100.0%
Taylor expanded in t around inf 78.7%
+-commutative78.7%
Simplified78.7%
if -9.5000000000000004e129 < t < 8.4000000000000004e-75Initial program 97.2%
Taylor expanded in z around inf 83.8%
div-inv83.8%
*-commutative83.8%
associate-*l*87.7%
div-inv87.8%
Applied egg-rr87.8%
Final simplification83.8%
(FPCore (x y z t a) :precision binary64 (if (or (<= t -8200000.0) (not (<= t 7.7e-88))) (+ x y) (+ x (/ y (/ a z)))))
double code(double x, double y, double z, double t, double a) {
double tmp;
if ((t <= -8200000.0) || !(t <= 7.7e-88)) {
tmp = x + y;
} else {
tmp = x + (y / (a / z));
}
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) :: tmp
if ((t <= (-8200000.0d0)) .or. (.not. (t <= 7.7d-88))) then
tmp = x + y
else
tmp = x + (y / (a / z))
end if
code = tmp
end function
public static double code(double x, double y, double z, double t, double a) {
double tmp;
if ((t <= -8200000.0) || !(t <= 7.7e-88)) {
tmp = x + y;
} else {
tmp = x + (y / (a / z));
}
return tmp;
}
def code(x, y, z, t, a): tmp = 0 if (t <= -8200000.0) or not (t <= 7.7e-88): tmp = x + y else: tmp = x + (y / (a / z)) return tmp
function code(x, y, z, t, a) tmp = 0.0 if ((t <= -8200000.0) || !(t <= 7.7e-88)) tmp = Float64(x + y); else tmp = Float64(x + Float64(y / Float64(a / z))); end return tmp end
function tmp_2 = code(x, y, z, t, a) tmp = 0.0; if ((t <= -8200000.0) || ~((t <= 7.7e-88))) tmp = x + y; else tmp = x + (y / (a / z)); end tmp_2 = tmp; end
code[x_, y_, z_, t_, a_] := If[Or[LessEqual[t, -8200000.0], N[Not[LessEqual[t, 7.7e-88]], $MachinePrecision]], N[(x + y), $MachinePrecision], N[(x + N[(y / N[(a / z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;t \leq -8200000 \lor \neg \left(t \leq 7.7 \cdot 10^{-88}\right):\\
\;\;\;\;x + y\\
\mathbf{else}:\\
\;\;\;\;x + \frac{y}{\frac{a}{z}}\\
\end{array}
\end{array}
if t < -8.2e6 or 7.70000000000000004e-88 < t Initial program 99.3%
+-commutative99.3%
fma-define99.3%
Simplified99.3%
Taylor expanded in t around inf 73.2%
+-commutative73.2%
Simplified73.2%
if -8.2e6 < t < 7.70000000000000004e-88Initial program 97.3%
clear-num97.2%
un-div-inv97.2%
Applied egg-rr97.2%
Taylor expanded in t around 0 84.7%
Final simplification78.2%
(FPCore (x y z t a) :precision binary64 (if (or (<= t -2050000000000.0) (not (<= t 2.4e-88))) (+ x y) x))
double code(double x, double y, double z, double t, double a) {
double tmp;
if ((t <= -2050000000000.0) || !(t <= 2.4e-88)) {
tmp = x + y;
} else {
tmp = x;
}
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) :: tmp
if ((t <= (-2050000000000.0d0)) .or. (.not. (t <= 2.4d-88))) then
tmp = x + y
else
tmp = x
end if
code = tmp
end function
public static double code(double x, double y, double z, double t, double a) {
double tmp;
if ((t <= -2050000000000.0) || !(t <= 2.4e-88)) {
tmp = x + y;
} else {
tmp = x;
}
return tmp;
}
def code(x, y, z, t, a): tmp = 0 if (t <= -2050000000000.0) or not (t <= 2.4e-88): tmp = x + y else: tmp = x return tmp
function code(x, y, z, t, a) tmp = 0.0 if ((t <= -2050000000000.0) || !(t <= 2.4e-88)) tmp = Float64(x + y); else tmp = x; end return tmp end
function tmp_2 = code(x, y, z, t, a) tmp = 0.0; if ((t <= -2050000000000.0) || ~((t <= 2.4e-88))) tmp = x + y; else tmp = x; end tmp_2 = tmp; end
code[x_, y_, z_, t_, a_] := If[Or[LessEqual[t, -2050000000000.0], N[Not[LessEqual[t, 2.4e-88]], $MachinePrecision]], N[(x + y), $MachinePrecision], x]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;t \leq -2050000000000 \lor \neg \left(t \leq 2.4 \cdot 10^{-88}\right):\\
\;\;\;\;x + y\\
\mathbf{else}:\\
\;\;\;\;x\\
\end{array}
\end{array}
if t < -2.05e12 or 2.4e-88 < t Initial program 99.3%
+-commutative99.3%
fma-define99.3%
Simplified99.3%
Taylor expanded in t around inf 73.5%
+-commutative73.5%
Simplified73.5%
if -2.05e12 < t < 2.4e-88Initial program 97.3%
+-commutative97.3%
fma-define97.3%
Simplified97.3%
Taylor expanded in y around 0 55.2%
Final simplification65.4%
(FPCore (x y z t a) :precision binary64 x)
double code(double x, double y, double z, double t, double a) {
return x;
}
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
end function
public static double code(double x, double y, double z, double t, double a) {
return x;
}
def code(x, y, z, t, a): return x
function code(x, y, z, t, a) return x end
function tmp = code(x, y, z, t, a) tmp = x; end
code[x_, y_, z_, t_, a_] := x
\begin{array}{l}
\\
x
\end{array}
Initial program 98.4%
+-commutative98.4%
fma-define98.4%
Simplified98.4%
Taylor expanded in y around 0 50.1%
(FPCore (x y z t a)
:precision binary64
(let* ((t_1 (+ x (* y (/ (- z t) (- a t))))))
(if (< y -8.508084860551241e-17)
t_1
(if (< y 2.894426862792089e-49)
(+ x (* (* y (- z t)) (/ 1.0 (- a t))))
t_1))))
double code(double x, double y, double z, double t, double a) {
double t_1 = x + (y * ((z - t) / (a - t)));
double tmp;
if (y < -8.508084860551241e-17) {
tmp = t_1;
} else if (y < 2.894426862792089e-49) {
tmp = x + ((y * (z - t)) * (1.0 / (a - t)));
} else {
tmp = 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 = x + (y * ((z - t) / (a - t)))
if (y < (-8.508084860551241d-17)) then
tmp = t_1
else if (y < 2.894426862792089d-49) then
tmp = x + ((y * (z - t)) * (1.0d0 / (a - t)))
else
tmp = 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 = x + (y * ((z - t) / (a - t)));
double tmp;
if (y < -8.508084860551241e-17) {
tmp = t_1;
} else if (y < 2.894426862792089e-49) {
tmp = x + ((y * (z - t)) * (1.0 / (a - t)));
} else {
tmp = t_1;
}
return tmp;
}
def code(x, y, z, t, a): t_1 = x + (y * ((z - t) / (a - t))) tmp = 0 if y < -8.508084860551241e-17: tmp = t_1 elif y < 2.894426862792089e-49: tmp = x + ((y * (z - t)) * (1.0 / (a - t))) else: tmp = t_1 return tmp
function code(x, y, z, t, a) t_1 = Float64(x + Float64(y * Float64(Float64(z - t) / Float64(a - t)))) tmp = 0.0 if (y < -8.508084860551241e-17) tmp = t_1; elseif (y < 2.894426862792089e-49) tmp = Float64(x + Float64(Float64(y * Float64(z - t)) * Float64(1.0 / Float64(a - t)))); else tmp = t_1; end return tmp end
function tmp_2 = code(x, y, z, t, a) t_1 = x + (y * ((z - t) / (a - t))); tmp = 0.0; if (y < -8.508084860551241e-17) tmp = t_1; elseif (y < 2.894426862792089e-49) tmp = x + ((y * (z - t)) * (1.0 / (a - t))); else tmp = t_1; end tmp_2 = tmp; end
code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(x + N[(y * N[(N[(z - t), $MachinePrecision] / N[(a - t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[Less[y, -8.508084860551241e-17], t$95$1, If[Less[y, 2.894426862792089e-49], N[(x + N[(N[(y * N[(z - t), $MachinePrecision]), $MachinePrecision] * N[(1.0 / N[(a - t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$1]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x + y \cdot \frac{z - t}{a - t}\\
\mathbf{if}\;y < -8.508084860551241 \cdot 10^{-17}:\\
\;\;\;\;t\_1\\
\mathbf{elif}\;y < 2.894426862792089 \cdot 10^{-49}:\\
\;\;\;\;x + \left(y \cdot \left(z - t\right)\right) \cdot \frac{1}{a - t}\\
\mathbf{else}:\\
\;\;\;\;t\_1\\
\end{array}
\end{array}
herbie shell --seed 2024170
(FPCore (x y z t a)
:name "Graphics.Rendering.Plot.Render.Plot.Axis:renderAxisLine from plot-0.2.3.4, B"
:precision binary64
:alt
(! :herbie-platform default (if (< y -8508084860551241/100000000000000000000000000000000) (+ x (* y (/ (- z t) (- a t)))) (if (< y 2894426862792089/10000000000000000000000000000000000000000000000000000000000000000) (+ x (* (* y (- z t)) (/ 1 (- a t)))) (+ x (* y (/ (- z t) (- a t)))))))
(+ x (* y (/ (- z t) (- a t)))))