
(FPCore (x y z t a) :precision binary64 (+ x (/ (* y (- z t)) (- z a))))
double code(double x, double y, double z, double t, double a) {
return x + ((y * (z - t)) / (z - 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)) / (z - a))
end function
public static double code(double x, double y, double z, double t, double a) {
return x + ((y * (z - t)) / (z - a));
}
def code(x, y, z, t, a): return x + ((y * (z - t)) / (z - a))
function code(x, y, z, t, a) return Float64(x + Float64(Float64(y * Float64(z - t)) / Float64(z - a))) end
function tmp = code(x, y, z, t, a) tmp = x + ((y * (z - t)) / (z - a)); end
code[x_, y_, z_, t_, a_] := N[(x + N[(N[(y * N[(z - t), $MachinePrecision]), $MachinePrecision] / N[(z - a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + \frac{y \cdot \left(z - t\right)}{z - a}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y z t a) :precision binary64 (+ x (/ (* y (- z t)) (- z a))))
double code(double x, double y, double z, double t, double a) {
return x + ((y * (z - t)) / (z - 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)) / (z - a))
end function
public static double code(double x, double y, double z, double t, double a) {
return x + ((y * (z - t)) / (z - a));
}
def code(x, y, z, t, a): return x + ((y * (z - t)) / (z - a))
function code(x, y, z, t, a) return Float64(x + Float64(Float64(y * Float64(z - t)) / Float64(z - a))) end
function tmp = code(x, y, z, t, a) tmp = x + ((y * (z - t)) / (z - a)); end
code[x_, y_, z_, t_, a_] := N[(x + N[(N[(y * N[(z - t), $MachinePrecision]), $MachinePrecision] / N[(z - a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + \frac{y \cdot \left(z - t\right)}{z - a}
\end{array}
(FPCore (x y z t a) :precision binary64 (+ x (* (/ (- z t) (- z a)) y)))
double code(double x, double y, double z, double t, double a) {
return x + (((z - t) / (z - a)) * y);
}
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 + (((z - t) / (z - a)) * y)
end function
public static double code(double x, double y, double z, double t, double a) {
return x + (((z - t) / (z - a)) * y);
}
def code(x, y, z, t, a): return x + (((z - t) / (z - a)) * y)
function code(x, y, z, t, a) return Float64(x + Float64(Float64(Float64(z - t) / Float64(z - a)) * y)) end
function tmp = code(x, y, z, t, a) tmp = x + (((z - t) / (z - a)) * y); end
code[x_, y_, z_, t_, a_] := N[(x + N[(N[(N[(z - t), $MachinePrecision] / N[(z - a), $MachinePrecision]), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + \frac{z - t}{z - a} \cdot y
\end{array}
Initial program 83.0%
associate-/l*99.1%
*-commutative99.1%
Applied egg-rr99.1%
Final simplification99.1%
(FPCore (x y z t a) :precision binary64 (if (or (<= z -3.4e-103) (not (<= z 3.4e-94))) (+ x (* y (/ z (- z a)))) (+ x (* y (/ t a)))))
double code(double x, double y, double z, double t, double a) {
double tmp;
if ((z <= -3.4e-103) || !(z <= 3.4e-94)) {
tmp = x + (y * (z / (z - a)));
} else {
tmp = x + (y * (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 <= (-3.4d-103)) .or. (.not. (z <= 3.4d-94))) then
tmp = x + (y * (z / (z - a)))
else
tmp = x + (y * (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 <= -3.4e-103) || !(z <= 3.4e-94)) {
tmp = x + (y * (z / (z - a)));
} else {
tmp = x + (y * (t / a));
}
return tmp;
}
def code(x, y, z, t, a): tmp = 0 if (z <= -3.4e-103) or not (z <= 3.4e-94): tmp = x + (y * (z / (z - a))) else: tmp = x + (y * (t / a)) return tmp
function code(x, y, z, t, a) tmp = 0.0 if ((z <= -3.4e-103) || !(z <= 3.4e-94)) tmp = Float64(x + Float64(y * Float64(z / Float64(z - a)))); else tmp = Float64(x + Float64(y * Float64(t / a))); end return tmp end
function tmp_2 = code(x, y, z, t, a) tmp = 0.0; if ((z <= -3.4e-103) || ~((z <= 3.4e-94))) tmp = x + (y * (z / (z - a))); else tmp = x + (y * (t / a)); end tmp_2 = tmp; end
code[x_, y_, z_, t_, a_] := If[Or[LessEqual[z, -3.4e-103], N[Not[LessEqual[z, 3.4e-94]], $MachinePrecision]], N[(x + N[(y * N[(z / N[(z - a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x + N[(y * N[(t / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -3.4 \cdot 10^{-103} \lor \neg \left(z \leq 3.4 \cdot 10^{-94}\right):\\
\;\;\;\;x + y \cdot \frac{z}{z - a}\\
\mathbf{else}:\\
\;\;\;\;x + y \cdot \frac{t}{a}\\
\end{array}
\end{array}
if z < -3.40000000000000003e-103 or 3.3999999999999998e-94 < z Initial program 78.4%
Taylor expanded in t around 0 66.2%
associate-/l*81.2%
Simplified81.2%
if -3.40000000000000003e-103 < z < 3.3999999999999998e-94Initial program 94.6%
associate-/l*97.2%
*-commutative97.2%
Applied egg-rr97.2%
Taylor expanded in z around 0 85.1%
Final simplification82.3%
(FPCore (x y z t a) :precision binary64 (if (or (<= t -1.02e+34) (not (<= t 1.65e-10))) (+ x (* y (/ t (- a z)))) (+ x (* y (/ z (- z a))))))
double code(double x, double y, double z, double t, double a) {
double tmp;
if ((t <= -1.02e+34) || !(t <= 1.65e-10)) {
tmp = x + (y * (t / (a - z)));
} else {
tmp = x + (y * (z / (z - 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 ((t <= (-1.02d+34)) .or. (.not. (t <= 1.65d-10))) then
tmp = x + (y * (t / (a - z)))
else
tmp = x + (y * (z / (z - a)))
end if
code = tmp
end function
public static double code(double x, double y, double z, double t, double a) {
double tmp;
if ((t <= -1.02e+34) || !(t <= 1.65e-10)) {
tmp = x + (y * (t / (a - z)));
} else {
tmp = x + (y * (z / (z - a)));
}
return tmp;
}
def code(x, y, z, t, a): tmp = 0 if (t <= -1.02e+34) or not (t <= 1.65e-10): tmp = x + (y * (t / (a - z))) else: tmp = x + (y * (z / (z - a))) return tmp
function code(x, y, z, t, a) tmp = 0.0 if ((t <= -1.02e+34) || !(t <= 1.65e-10)) tmp = Float64(x + Float64(y * Float64(t / Float64(a - z)))); else tmp = Float64(x + Float64(y * Float64(z / Float64(z - a)))); end return tmp end
function tmp_2 = code(x, y, z, t, a) tmp = 0.0; if ((t <= -1.02e+34) || ~((t <= 1.65e-10))) tmp = x + (y * (t / (a - z))); else tmp = x + (y * (z / (z - a))); end tmp_2 = tmp; end
code[x_, y_, z_, t_, a_] := If[Or[LessEqual[t, -1.02e+34], N[Not[LessEqual[t, 1.65e-10]], $MachinePrecision]], N[(x + N[(y * N[(t / N[(a - z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x + N[(y * N[(z / N[(z - a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;t \leq -1.02 \cdot 10^{+34} \lor \neg \left(t \leq 1.65 \cdot 10^{-10}\right):\\
\;\;\;\;x + y \cdot \frac{t}{a - z}\\
\mathbf{else}:\\
\;\;\;\;x + y \cdot \frac{z}{z - a}\\
\end{array}
\end{array}
if t < -1.02e34 or 1.65e-10 < t Initial program 82.0%
associate-/l*98.1%
*-commutative98.1%
Applied egg-rr98.1%
Taylor expanded in t around inf 86.1%
neg-mul-186.1%
distribute-neg-frac286.1%
sub-neg86.1%
distribute-neg-in86.1%
remove-double-neg86.1%
Simplified86.1%
Taylor expanded in t around 0 86.1%
if -1.02e34 < t < 1.65e-10Initial program 83.8%
Taylor expanded in t around 0 76.5%
associate-/l*92.6%
Simplified92.6%
Final simplification89.7%
(FPCore (x y z t a) :precision binary64 (if (<= z -3.5e-232) (+ x y) (if (<= z 4.1e-265) (* (/ y a) (- t z)) (if (<= z 2.35e-38) x (+ x y)))))
double code(double x, double y, double z, double t, double a) {
double tmp;
if (z <= -3.5e-232) {
tmp = x + y;
} else if (z <= 4.1e-265) {
tmp = (y / a) * (t - z);
} else if (z <= 2.35e-38) {
tmp = x;
} else {
tmp = x + y;
}
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 <= (-3.5d-232)) then
tmp = x + y
else if (z <= 4.1d-265) then
tmp = (y / a) * (t - z)
else if (z <= 2.35d-38) then
tmp = x
else
tmp = x + y
end if
code = tmp
end function
public static double code(double x, double y, double z, double t, double a) {
double tmp;
if (z <= -3.5e-232) {
tmp = x + y;
} else if (z <= 4.1e-265) {
tmp = (y / a) * (t - z);
} else if (z <= 2.35e-38) {
tmp = x;
} else {
tmp = x + y;
}
return tmp;
}
def code(x, y, z, t, a): tmp = 0 if z <= -3.5e-232: tmp = x + y elif z <= 4.1e-265: tmp = (y / a) * (t - z) elif z <= 2.35e-38: tmp = x else: tmp = x + y return tmp
function code(x, y, z, t, a) tmp = 0.0 if (z <= -3.5e-232) tmp = Float64(x + y); elseif (z <= 4.1e-265) tmp = Float64(Float64(y / a) * Float64(t - z)); elseif (z <= 2.35e-38) tmp = x; else tmp = Float64(x + y); end return tmp end
function tmp_2 = code(x, y, z, t, a) tmp = 0.0; if (z <= -3.5e-232) tmp = x + y; elseif (z <= 4.1e-265) tmp = (y / a) * (t - z); elseif (z <= 2.35e-38) tmp = x; else tmp = x + y; end tmp_2 = tmp; end
code[x_, y_, z_, t_, a_] := If[LessEqual[z, -3.5e-232], N[(x + y), $MachinePrecision], If[LessEqual[z, 4.1e-265], N[(N[(y / a), $MachinePrecision] * N[(t - z), $MachinePrecision]), $MachinePrecision], If[LessEqual[z, 2.35e-38], x, N[(x + y), $MachinePrecision]]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -3.5 \cdot 10^{-232}:\\
\;\;\;\;x + y\\
\mathbf{elif}\;z \leq 4.1 \cdot 10^{-265}:\\
\;\;\;\;\frac{y}{a} \cdot \left(t - z\right)\\
\mathbf{elif}\;z \leq 2.35 \cdot 10^{-38}:\\
\;\;\;\;x\\
\mathbf{else}:\\
\;\;\;\;x + y\\
\end{array}
\end{array}
if z < -3.4999999999999998e-232 or 2.34999999999999999e-38 < z Initial program 77.9%
Taylor expanded in z around inf 68.7%
+-commutative68.7%
Simplified68.7%
if -3.4999999999999998e-232 < z < 4.1e-265Initial program 95.2%
Taylor expanded in x around 0 71.2%
associate-*l/71.1%
Simplified71.1%
Taylor expanded in z around 0 66.9%
associate-*r/66.9%
neg-mul-166.9%
Simplified66.9%
Taylor expanded in y around 0 67.1%
associate-*r/66.4%
*-rgt-identity66.4%
*-rgt-identity66.4%
div-sub66.4%
sub-neg66.4%
neg-mul-166.4%
distribute-lft-in66.4%
associate-/l*66.4%
neg-mul-166.4%
distribute-rgt-neg-in66.4%
associate-*r/67.1%
*-commutative67.1%
associate-*r/66.9%
unsub-neg66.9%
distribute-lft-out--66.9%
neg-mul-166.9%
distribute-lft-neg-in66.9%
cancel-sign-sub66.9%
+-commutative66.9%
Simplified66.9%
if 4.1e-265 < z < 2.34999999999999999e-38Initial program 97.9%
Taylor expanded in x around inf 61.4%
Final simplification67.2%
(FPCore (x y z t a) :precision binary64 (if (or (<= z -1.15e+65) (not (<= z 1.65e+44))) (+ x y) (+ x (* y (/ t a)))))
double code(double x, double y, double z, double t, double a) {
double tmp;
if ((z <= -1.15e+65) || !(z <= 1.65e+44)) {
tmp = x + y;
} else {
tmp = x + (y * (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 <= (-1.15d+65)) .or. (.not. (z <= 1.65d+44))) then
tmp = x + y
else
tmp = x + (y * (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 <= -1.15e+65) || !(z <= 1.65e+44)) {
tmp = x + y;
} else {
tmp = x + (y * (t / a));
}
return tmp;
}
def code(x, y, z, t, a): tmp = 0 if (z <= -1.15e+65) or not (z <= 1.65e+44): tmp = x + y else: tmp = x + (y * (t / a)) return tmp
function code(x, y, z, t, a) tmp = 0.0 if ((z <= -1.15e+65) || !(z <= 1.65e+44)) tmp = Float64(x + y); else tmp = Float64(x + Float64(y * Float64(t / a))); end return tmp end
function tmp_2 = code(x, y, z, t, a) tmp = 0.0; if ((z <= -1.15e+65) || ~((z <= 1.65e+44))) tmp = x + y; else tmp = x + (y * (t / a)); end tmp_2 = tmp; end
code[x_, y_, z_, t_, a_] := If[Or[LessEqual[z, -1.15e+65], N[Not[LessEqual[z, 1.65e+44]], $MachinePrecision]], N[(x + y), $MachinePrecision], N[(x + N[(y * N[(t / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -1.15 \cdot 10^{+65} \lor \neg \left(z \leq 1.65 \cdot 10^{+44}\right):\\
\;\;\;\;x + y\\
\mathbf{else}:\\
\;\;\;\;x + y \cdot \frac{t}{a}\\
\end{array}
\end{array}
if z < -1.15e65 or 1.65000000000000007e44 < z Initial program 68.0%
Taylor expanded in z around inf 77.5%
+-commutative77.5%
Simplified77.5%
if -1.15e65 < z < 1.65000000000000007e44Initial program 95.2%
associate-/l*98.5%
*-commutative98.5%
Applied egg-rr98.5%
Taylor expanded in z around 0 75.0%
Final simplification76.1%
(FPCore (x y z t a) :precision binary64 (if (or (<= z -1.85e+20) (not (<= z 2.5e-38))) (+ x y) x))
double code(double x, double y, double z, double t, double a) {
double tmp;
if ((z <= -1.85e+20) || !(z <= 2.5e-38)) {
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 ((z <= (-1.85d+20)) .or. (.not. (z <= 2.5d-38))) 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 ((z <= -1.85e+20) || !(z <= 2.5e-38)) {
tmp = x + y;
} else {
tmp = x;
}
return tmp;
}
def code(x, y, z, t, a): tmp = 0 if (z <= -1.85e+20) or not (z <= 2.5e-38): tmp = x + y else: tmp = x return tmp
function code(x, y, z, t, a) tmp = 0.0 if ((z <= -1.85e+20) || !(z <= 2.5e-38)) tmp = Float64(x + y); else tmp = x; end return tmp end
function tmp_2 = code(x, y, z, t, a) tmp = 0.0; if ((z <= -1.85e+20) || ~((z <= 2.5e-38))) tmp = x + y; else tmp = x; end tmp_2 = tmp; end
code[x_, y_, z_, t_, a_] := If[Or[LessEqual[z, -1.85e+20], N[Not[LessEqual[z, 2.5e-38]], $MachinePrecision]], N[(x + y), $MachinePrecision], x]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -1.85 \cdot 10^{+20} \lor \neg \left(z \leq 2.5 \cdot 10^{-38}\right):\\
\;\;\;\;x + y\\
\mathbf{else}:\\
\;\;\;\;x\\
\end{array}
\end{array}
if z < -1.85e20 or 2.50000000000000017e-38 < z Initial program 73.1%
Taylor expanded in z around inf 72.9%
+-commutative72.9%
Simplified72.9%
if -1.85e20 < z < 2.50000000000000017e-38Initial program 95.6%
Taylor expanded in x around inf 55.1%
Final simplification65.1%
(FPCore (x y z t a) :precision binary64 (if (<= x -5.7e-208) x (if (<= x 1.05e-139) y x)))
double code(double x, double y, double z, double t, double a) {
double tmp;
if (x <= -5.7e-208) {
tmp = x;
} else if (x <= 1.05e-139) {
tmp = 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 (x <= (-5.7d-208)) then
tmp = x
else if (x <= 1.05d-139) then
tmp = 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 (x <= -5.7e-208) {
tmp = x;
} else if (x <= 1.05e-139) {
tmp = y;
} else {
tmp = x;
}
return tmp;
}
def code(x, y, z, t, a): tmp = 0 if x <= -5.7e-208: tmp = x elif x <= 1.05e-139: tmp = y else: tmp = x return tmp
function code(x, y, z, t, a) tmp = 0.0 if (x <= -5.7e-208) tmp = x; elseif (x <= 1.05e-139) tmp = y; else tmp = x; end return tmp end
function tmp_2 = code(x, y, z, t, a) tmp = 0.0; if (x <= -5.7e-208) tmp = x; elseif (x <= 1.05e-139) tmp = y; else tmp = x; end tmp_2 = tmp; end
code[x_, y_, z_, t_, a_] := If[LessEqual[x, -5.7e-208], x, If[LessEqual[x, 1.05e-139], y, x]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -5.7 \cdot 10^{-208}:\\
\;\;\;\;x\\
\mathbf{elif}\;x \leq 1.05 \cdot 10^{-139}:\\
\;\;\;\;y\\
\mathbf{else}:\\
\;\;\;\;x\\
\end{array}
\end{array}
if x < -5.7000000000000004e-208 or 1.05000000000000004e-139 < x Initial program 84.5%
Taylor expanded in x around inf 59.5%
if -5.7000000000000004e-208 < x < 1.05000000000000004e-139Initial program 77.9%
Taylor expanded in x around 0 68.6%
associate-*l/74.6%
Simplified74.6%
Taylor expanded in z around inf 49.4%
Taylor expanded in z around inf 43.1%
Final simplification55.6%
(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 83.0%
Taylor expanded in x around inf 48.5%
Final simplification48.5%
(FPCore (x y z t a) :precision binary64 (+ x (/ y (/ (- z a) (- z t)))))
double code(double x, double y, double z, double t, double a) {
return x + (y / ((z - a) / (z - 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 - a) / (z - t)))
end function
public static double code(double x, double y, double z, double t, double a) {
return x + (y / ((z - a) / (z - t)));
}
def code(x, y, z, t, a): return x + (y / ((z - a) / (z - t)))
function code(x, y, z, t, a) return Float64(x + Float64(y / Float64(Float64(z - a) / Float64(z - t)))) end
function tmp = code(x, y, z, t, a) tmp = x + (y / ((z - a) / (z - t))); end
code[x_, y_, z_, t_, a_] := N[(x + N[(y / N[(N[(z - a), $MachinePrecision] / N[(z - t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + \frac{y}{\frac{z - a}{z - t}}
\end{array}
herbie shell --seed 2024078
(FPCore (x y z t a)
:name "Graphics.Rendering.Plot.Render.Plot.Axis:renderAxisTicks from plot-0.2.3.4, A"
:precision binary64
:alt
(+ x (/ y (/ (- z a) (- z t))))
(+ x (/ (* y (- z t)) (- z a))))