
(FPCore (x y z) :precision binary64 (+ x (* (- y x) z)))
double code(double x, double y, double z) {
return x + ((y - x) * z);
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = x + ((y - x) * z)
end function
public static double code(double x, double y, double z) {
return x + ((y - x) * z);
}
def code(x, y, z): return x + ((y - x) * z)
function code(x, y, z) return Float64(x + Float64(Float64(y - x) * z)) end
function tmp = code(x, y, z) tmp = x + ((y - x) * z); end
code[x_, y_, z_] := N[(x + N[(N[(y - x), $MachinePrecision] * z), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + \left(y - x\right) \cdot z
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y z) :precision binary64 (+ x (* (- y x) z)))
double code(double x, double y, double z) {
return x + ((y - x) * z);
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = x + ((y - x) * z)
end function
public static double code(double x, double y, double z) {
return x + ((y - x) * z);
}
def code(x, y, z): return x + ((y - x) * z)
function code(x, y, z) return Float64(x + Float64(Float64(y - x) * z)) end
function tmp = code(x, y, z) tmp = x + ((y - x) * z); end
code[x_, y_, z_] := N[(x + N[(N[(y - x), $MachinePrecision] * z), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + \left(y - x\right) \cdot z
\end{array}
(FPCore (x y z) :precision binary64 (fma (- y x) z x))
double code(double x, double y, double z) {
return fma((y - x), z, x);
}
function code(x, y, z) return fma(Float64(y - x), z, x) end
code[x_, y_, z_] := N[(N[(y - x), $MachinePrecision] * z + x), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(y - x, z, x\right)
\end{array}
Initial program 100.0%
+-commutative100.0%
fma-define100.0%
Simplified100.0%
(FPCore (x y z)
:precision binary64
(let* ((t_0 (* x (- z))))
(if (<= z -3.3e+90)
(* y z)
(if (<= z -470.0)
t_0
(if (<= z -4.2e-119)
(* y z)
(if (<= z 5.7e-86)
x
(if (<= z 5.2e-20)
(* y z)
(if (<= z 1.0)
x
(if (or (<= z 7.5e+49) (not (<= z 4.5e+104)))
t_0
(* y z))))))))))
double code(double x, double y, double z) {
double t_0 = x * -z;
double tmp;
if (z <= -3.3e+90) {
tmp = y * z;
} else if (z <= -470.0) {
tmp = t_0;
} else if (z <= -4.2e-119) {
tmp = y * z;
} else if (z <= 5.7e-86) {
tmp = x;
} else if (z <= 5.2e-20) {
tmp = y * z;
} else if (z <= 1.0) {
tmp = x;
} else if ((z <= 7.5e+49) || !(z <= 4.5e+104)) {
tmp = t_0;
} else {
tmp = y * z;
}
return tmp;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8) :: t_0
real(8) :: tmp
t_0 = x * -z
if (z <= (-3.3d+90)) then
tmp = y * z
else if (z <= (-470.0d0)) then
tmp = t_0
else if (z <= (-4.2d-119)) then
tmp = y * z
else if (z <= 5.7d-86) then
tmp = x
else if (z <= 5.2d-20) then
tmp = y * z
else if (z <= 1.0d0) then
tmp = x
else if ((z <= 7.5d+49) .or. (.not. (z <= 4.5d+104))) then
tmp = t_0
else
tmp = y * z
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double t_0 = x * -z;
double tmp;
if (z <= -3.3e+90) {
tmp = y * z;
} else if (z <= -470.0) {
tmp = t_0;
} else if (z <= -4.2e-119) {
tmp = y * z;
} else if (z <= 5.7e-86) {
tmp = x;
} else if (z <= 5.2e-20) {
tmp = y * z;
} else if (z <= 1.0) {
tmp = x;
} else if ((z <= 7.5e+49) || !(z <= 4.5e+104)) {
tmp = t_0;
} else {
tmp = y * z;
}
return tmp;
}
def code(x, y, z): t_0 = x * -z tmp = 0 if z <= -3.3e+90: tmp = y * z elif z <= -470.0: tmp = t_0 elif z <= -4.2e-119: tmp = y * z elif z <= 5.7e-86: tmp = x elif z <= 5.2e-20: tmp = y * z elif z <= 1.0: tmp = x elif (z <= 7.5e+49) or not (z <= 4.5e+104): tmp = t_0 else: tmp = y * z return tmp
function code(x, y, z) t_0 = Float64(x * Float64(-z)) tmp = 0.0 if (z <= -3.3e+90) tmp = Float64(y * z); elseif (z <= -470.0) tmp = t_0; elseif (z <= -4.2e-119) tmp = Float64(y * z); elseif (z <= 5.7e-86) tmp = x; elseif (z <= 5.2e-20) tmp = Float64(y * z); elseif (z <= 1.0) tmp = x; elseif ((z <= 7.5e+49) || !(z <= 4.5e+104)) tmp = t_0; else tmp = Float64(y * z); end return tmp end
function tmp_2 = code(x, y, z) t_0 = x * -z; tmp = 0.0; if (z <= -3.3e+90) tmp = y * z; elseif (z <= -470.0) tmp = t_0; elseif (z <= -4.2e-119) tmp = y * z; elseif (z <= 5.7e-86) tmp = x; elseif (z <= 5.2e-20) tmp = y * z; elseif (z <= 1.0) tmp = x; elseif ((z <= 7.5e+49) || ~((z <= 4.5e+104))) tmp = t_0; else tmp = y * z; end tmp_2 = tmp; end
code[x_, y_, z_] := Block[{t$95$0 = N[(x * (-z)), $MachinePrecision]}, If[LessEqual[z, -3.3e+90], N[(y * z), $MachinePrecision], If[LessEqual[z, -470.0], t$95$0, If[LessEqual[z, -4.2e-119], N[(y * z), $MachinePrecision], If[LessEqual[z, 5.7e-86], x, If[LessEqual[z, 5.2e-20], N[(y * z), $MachinePrecision], If[LessEqual[z, 1.0], x, If[Or[LessEqual[z, 7.5e+49], N[Not[LessEqual[z, 4.5e+104]], $MachinePrecision]], t$95$0, N[(y * z), $MachinePrecision]]]]]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := x \cdot \left(-z\right)\\
\mathbf{if}\;z \leq -3.3 \cdot 10^{+90}:\\
\;\;\;\;y \cdot z\\
\mathbf{elif}\;z \leq -470:\\
\;\;\;\;t\_0\\
\mathbf{elif}\;z \leq -4.2 \cdot 10^{-119}:\\
\;\;\;\;y \cdot z\\
\mathbf{elif}\;z \leq 5.7 \cdot 10^{-86}:\\
\;\;\;\;x\\
\mathbf{elif}\;z \leq 5.2 \cdot 10^{-20}:\\
\;\;\;\;y \cdot z\\
\mathbf{elif}\;z \leq 1:\\
\;\;\;\;x\\
\mathbf{elif}\;z \leq 7.5 \cdot 10^{+49} \lor \neg \left(z \leq 4.5 \cdot 10^{+104}\right):\\
\;\;\;\;t\_0\\
\mathbf{else}:\\
\;\;\;\;y \cdot z\\
\end{array}
\end{array}
if z < -3.30000000000000008e90 or -470 < z < -4.2e-119 or 5.7000000000000004e-86 < z < 5.1999999999999999e-20 or 7.4999999999999995e49 < z < 4.4999999999999998e104Initial program 99.9%
Taylor expanded in x around 0 65.8%
if -3.30000000000000008e90 < z < -470 or 1 < z < 7.4999999999999995e49 or 4.4999999999999998e104 < z Initial program 99.9%
Taylor expanded in x around inf 64.3%
mul-1-neg64.3%
unsub-neg64.3%
Simplified64.3%
Taylor expanded in z around inf 62.4%
mul-1-neg62.4%
*-commutative62.4%
distribute-rgt-neg-in62.4%
Simplified62.4%
if -4.2e-119 < z < 5.7000000000000004e-86 or 5.1999999999999999e-20 < z < 1Initial program 100.0%
Taylor expanded in z around 0 89.3%
Final simplification71.4%
(FPCore (x y z)
:precision binary64
(let* ((t_0 (* (- y x) z)))
(if (<= z -4.2e-119)
t_0
(if (<= z 5.6e-86)
(* x (- 1.0 z))
(if (<= z 9.5e-20) (* y z) (if (<= z 3.8) (- x (* x z)) t_0))))))
double code(double x, double y, double z) {
double t_0 = (y - x) * z;
double tmp;
if (z <= -4.2e-119) {
tmp = t_0;
} else if (z <= 5.6e-86) {
tmp = x * (1.0 - z);
} else if (z <= 9.5e-20) {
tmp = y * z;
} else if (z <= 3.8) {
tmp = x - (x * z);
} else {
tmp = t_0;
}
return tmp;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8) :: t_0
real(8) :: tmp
t_0 = (y - x) * z
if (z <= (-4.2d-119)) then
tmp = t_0
else if (z <= 5.6d-86) then
tmp = x * (1.0d0 - z)
else if (z <= 9.5d-20) then
tmp = y * z
else if (z <= 3.8d0) then
tmp = x - (x * z)
else
tmp = t_0
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double t_0 = (y - x) * z;
double tmp;
if (z <= -4.2e-119) {
tmp = t_0;
} else if (z <= 5.6e-86) {
tmp = x * (1.0 - z);
} else if (z <= 9.5e-20) {
tmp = y * z;
} else if (z <= 3.8) {
tmp = x - (x * z);
} else {
tmp = t_0;
}
return tmp;
}
def code(x, y, z): t_0 = (y - x) * z tmp = 0 if z <= -4.2e-119: tmp = t_0 elif z <= 5.6e-86: tmp = x * (1.0 - z) elif z <= 9.5e-20: tmp = y * z elif z <= 3.8: tmp = x - (x * z) else: tmp = t_0 return tmp
function code(x, y, z) t_0 = Float64(Float64(y - x) * z) tmp = 0.0 if (z <= -4.2e-119) tmp = t_0; elseif (z <= 5.6e-86) tmp = Float64(x * Float64(1.0 - z)); elseif (z <= 9.5e-20) tmp = Float64(y * z); elseif (z <= 3.8) tmp = Float64(x - Float64(x * z)); else tmp = t_0; end return tmp end
function tmp_2 = code(x, y, z) t_0 = (y - x) * z; tmp = 0.0; if (z <= -4.2e-119) tmp = t_0; elseif (z <= 5.6e-86) tmp = x * (1.0 - z); elseif (z <= 9.5e-20) tmp = y * z; elseif (z <= 3.8) tmp = x - (x * z); else tmp = t_0; end tmp_2 = tmp; end
code[x_, y_, z_] := Block[{t$95$0 = N[(N[(y - x), $MachinePrecision] * z), $MachinePrecision]}, If[LessEqual[z, -4.2e-119], t$95$0, If[LessEqual[z, 5.6e-86], N[(x * N[(1.0 - z), $MachinePrecision]), $MachinePrecision], If[LessEqual[z, 9.5e-20], N[(y * z), $MachinePrecision], If[LessEqual[z, 3.8], N[(x - N[(x * z), $MachinePrecision]), $MachinePrecision], t$95$0]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(y - x\right) \cdot z\\
\mathbf{if}\;z \leq -4.2 \cdot 10^{-119}:\\
\;\;\;\;t\_0\\
\mathbf{elif}\;z \leq 5.6 \cdot 10^{-86}:\\
\;\;\;\;x \cdot \left(1 - z\right)\\
\mathbf{elif}\;z \leq 9.5 \cdot 10^{-20}:\\
\;\;\;\;y \cdot z\\
\mathbf{elif}\;z \leq 3.8:\\
\;\;\;\;x - x \cdot z\\
\mathbf{else}:\\
\;\;\;\;t\_0\\
\end{array}
\end{array}
if z < -4.2e-119 or 3.7999999999999998 < z Initial program 99.9%
Taylor expanded in z around inf 94.4%
if -4.2e-119 < z < 5.60000000000000019e-86Initial program 100.0%
Taylor expanded in x around inf 90.8%
mul-1-neg90.8%
unsub-neg90.8%
Simplified90.8%
if 5.60000000000000019e-86 < z < 9.5e-20Initial program 99.9%
Taylor expanded in x around 0 63.1%
if 9.5e-20 < z < 3.7999999999999998Initial program 100.0%
Taylor expanded in x around inf 99.6%
mul-1-neg99.6%
unsub-neg99.6%
Simplified99.6%
sub-neg99.6%
distribute-rgt-in100.0%
*-un-lft-identity100.0%
distribute-lft-neg-in100.0%
unsub-neg100.0%
*-commutative100.0%
Applied egg-rr100.0%
Final simplification91.7%
(FPCore (x y z)
:precision binary64
(let* ((t_0 (* (- y x) z)) (t_1 (* x (- 1.0 z))))
(if (<= z -4.2e-119)
t_0
(if (<= z 5.7e-86)
t_1
(if (<= z 1.1e-16) (* y z) (if (<= z 0.0086) t_1 t_0))))))
double code(double x, double y, double z) {
double t_0 = (y - x) * z;
double t_1 = x * (1.0 - z);
double tmp;
if (z <= -4.2e-119) {
tmp = t_0;
} else if (z <= 5.7e-86) {
tmp = t_1;
} else if (z <= 1.1e-16) {
tmp = y * z;
} else if (z <= 0.0086) {
tmp = t_1;
} else {
tmp = t_0;
}
return tmp;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8) :: t_0
real(8) :: t_1
real(8) :: tmp
t_0 = (y - x) * z
t_1 = x * (1.0d0 - z)
if (z <= (-4.2d-119)) then
tmp = t_0
else if (z <= 5.7d-86) then
tmp = t_1
else if (z <= 1.1d-16) then
tmp = y * z
else if (z <= 0.0086d0) then
tmp = t_1
else
tmp = t_0
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double t_0 = (y - x) * z;
double t_1 = x * (1.0 - z);
double tmp;
if (z <= -4.2e-119) {
tmp = t_0;
} else if (z <= 5.7e-86) {
tmp = t_1;
} else if (z <= 1.1e-16) {
tmp = y * z;
} else if (z <= 0.0086) {
tmp = t_1;
} else {
tmp = t_0;
}
return tmp;
}
def code(x, y, z): t_0 = (y - x) * z t_1 = x * (1.0 - z) tmp = 0 if z <= -4.2e-119: tmp = t_0 elif z <= 5.7e-86: tmp = t_1 elif z <= 1.1e-16: tmp = y * z elif z <= 0.0086: tmp = t_1 else: tmp = t_0 return tmp
function code(x, y, z) t_0 = Float64(Float64(y - x) * z) t_1 = Float64(x * Float64(1.0 - z)) tmp = 0.0 if (z <= -4.2e-119) tmp = t_0; elseif (z <= 5.7e-86) tmp = t_1; elseif (z <= 1.1e-16) tmp = Float64(y * z); elseif (z <= 0.0086) tmp = t_1; else tmp = t_0; end return tmp end
function tmp_2 = code(x, y, z) t_0 = (y - x) * z; t_1 = x * (1.0 - z); tmp = 0.0; if (z <= -4.2e-119) tmp = t_0; elseif (z <= 5.7e-86) tmp = t_1; elseif (z <= 1.1e-16) tmp = y * z; elseif (z <= 0.0086) tmp = t_1; else tmp = t_0; end tmp_2 = tmp; end
code[x_, y_, z_] := Block[{t$95$0 = N[(N[(y - x), $MachinePrecision] * z), $MachinePrecision]}, Block[{t$95$1 = N[(x * N[(1.0 - z), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[z, -4.2e-119], t$95$0, If[LessEqual[z, 5.7e-86], t$95$1, If[LessEqual[z, 1.1e-16], N[(y * z), $MachinePrecision], If[LessEqual[z, 0.0086], t$95$1, t$95$0]]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(y - x\right) \cdot z\\
t_1 := x \cdot \left(1 - z\right)\\
\mathbf{if}\;z \leq -4.2 \cdot 10^{-119}:\\
\;\;\;\;t\_0\\
\mathbf{elif}\;z \leq 5.7 \cdot 10^{-86}:\\
\;\;\;\;t\_1\\
\mathbf{elif}\;z \leq 1.1 \cdot 10^{-16}:\\
\;\;\;\;y \cdot z\\
\mathbf{elif}\;z \leq 0.0086:\\
\;\;\;\;t\_1\\
\mathbf{else}:\\
\;\;\;\;t\_0\\
\end{array}
\end{array}
if z < -4.2e-119 or 0.0086 < z Initial program 99.9%
Taylor expanded in z around inf 94.4%
if -4.2e-119 < z < 5.7000000000000004e-86 or 1.1e-16 < z < 0.0086Initial program 100.0%
Taylor expanded in x around inf 91.3%
mul-1-neg91.3%
unsub-neg91.3%
Simplified91.3%
if 5.7000000000000004e-86 < z < 1.1e-16Initial program 99.9%
Taylor expanded in x around 0 63.1%
Final simplification91.7%
(FPCore (x y z) :precision binary64 (if (or (<= x -1.95e-28) (not (<= x 1.32e-120))) (* x (- 1.0 z)) (* y z)))
double code(double x, double y, double z) {
double tmp;
if ((x <= -1.95e-28) || !(x <= 1.32e-120)) {
tmp = x * (1.0 - z);
} else {
tmp = y * z;
}
return tmp;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8) :: tmp
if ((x <= (-1.95d-28)) .or. (.not. (x <= 1.32d-120))) then
tmp = x * (1.0d0 - z)
else
tmp = y * z
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double tmp;
if ((x <= -1.95e-28) || !(x <= 1.32e-120)) {
tmp = x * (1.0 - z);
} else {
tmp = y * z;
}
return tmp;
}
def code(x, y, z): tmp = 0 if (x <= -1.95e-28) or not (x <= 1.32e-120): tmp = x * (1.0 - z) else: tmp = y * z return tmp
function code(x, y, z) tmp = 0.0 if ((x <= -1.95e-28) || !(x <= 1.32e-120)) tmp = Float64(x * Float64(1.0 - z)); else tmp = Float64(y * z); end return tmp end
function tmp_2 = code(x, y, z) tmp = 0.0; if ((x <= -1.95e-28) || ~((x <= 1.32e-120))) tmp = x * (1.0 - z); else tmp = y * z; end tmp_2 = tmp; end
code[x_, y_, z_] := If[Or[LessEqual[x, -1.95e-28], N[Not[LessEqual[x, 1.32e-120]], $MachinePrecision]], N[(x * N[(1.0 - z), $MachinePrecision]), $MachinePrecision], N[(y * z), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.95 \cdot 10^{-28} \lor \neg \left(x \leq 1.32 \cdot 10^{-120}\right):\\
\;\;\;\;x \cdot \left(1 - z\right)\\
\mathbf{else}:\\
\;\;\;\;y \cdot z\\
\end{array}
\end{array}
if x < -1.94999999999999999e-28 or 1.32000000000000004e-120 < x Initial program 99.9%
Taylor expanded in x around inf 81.8%
mul-1-neg81.8%
unsub-neg81.8%
Simplified81.8%
if -1.94999999999999999e-28 < x < 1.32000000000000004e-120Initial program 100.0%
Taylor expanded in x around 0 72.2%
Final simplification78.2%
(FPCore (x y z) :precision binary64 (if (or (<= z -3.4e-123) (not (<= z 4e-86))) (* y z) x))
double code(double x, double y, double z) {
double tmp;
if ((z <= -3.4e-123) || !(z <= 4e-86)) {
tmp = y * z;
} else {
tmp = x;
}
return tmp;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8) :: tmp
if ((z <= (-3.4d-123)) .or. (.not. (z <= 4d-86))) then
tmp = y * z
else
tmp = x
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double tmp;
if ((z <= -3.4e-123) || !(z <= 4e-86)) {
tmp = y * z;
} else {
tmp = x;
}
return tmp;
}
def code(x, y, z): tmp = 0 if (z <= -3.4e-123) or not (z <= 4e-86): tmp = y * z else: tmp = x return tmp
function code(x, y, z) tmp = 0.0 if ((z <= -3.4e-123) || !(z <= 4e-86)) tmp = Float64(y * z); else tmp = x; end return tmp end
function tmp_2 = code(x, y, z) tmp = 0.0; if ((z <= -3.4e-123) || ~((z <= 4e-86))) tmp = y * z; else tmp = x; end tmp_2 = tmp; end
code[x_, y_, z_] := If[Or[LessEqual[z, -3.4e-123], N[Not[LessEqual[z, 4e-86]], $MachinePrecision]], N[(y * z), $MachinePrecision], x]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -3.4 \cdot 10^{-123} \lor \neg \left(z \leq 4 \cdot 10^{-86}\right):\\
\;\;\;\;y \cdot z\\
\mathbf{else}:\\
\;\;\;\;x\\
\end{array}
\end{array}
if z < -3.4000000000000001e-123 or 4.00000000000000034e-86 < z Initial program 99.9%
Taylor expanded in x around 0 52.7%
if -3.4000000000000001e-123 < z < 4.00000000000000034e-86Initial program 100.0%
Taylor expanded in z around 0 90.8%
Final simplification63.1%
(FPCore (x y z) :precision binary64 (+ x (* (- y x) z)))
double code(double x, double y, double z) {
return x + ((y - x) * z);
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = x + ((y - x) * z)
end function
public static double code(double x, double y, double z) {
return x + ((y - x) * z);
}
def code(x, y, z): return x + ((y - x) * z)
function code(x, y, z) return Float64(x + Float64(Float64(y - x) * z)) end
function tmp = code(x, y, z) tmp = x + ((y - x) * z); end
code[x_, y_, z_] := N[(x + N[(N[(y - x), $MachinePrecision] * z), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + \left(y - x\right) \cdot z
\end{array}
Initial program 100.0%
(FPCore (x y z) :precision binary64 x)
double code(double x, double y, double z) {
return x;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = x
end function
public static double code(double x, double y, double z) {
return x;
}
def code(x, y, z): return x
function code(x, y, z) return x end
function tmp = code(x, y, z) tmp = x; end
code[x_, y_, z_] := x
\begin{array}{l}
\\
x
\end{array}
Initial program 100.0%
Taylor expanded in z around 0 32.5%
herbie shell --seed 2024085
(FPCore (x y z)
:name "Diagrams.ThreeD.Shapes:frustum from diagrams-lib-1.3.0.3, B"
:precision binary64
(+ x (* (- y x) z)))