
(FPCore (x y z) :precision binary64 (/ (/ 1.0 x) (* y (+ 1.0 (* z z)))))
double code(double x, double y, double z) {
return (1.0 / x) / (y * (1.0 + (z * z)));
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = (1.0d0 / x) / (y * (1.0d0 + (z * z)))
end function
public static double code(double x, double y, double z) {
return (1.0 / x) / (y * (1.0 + (z * z)));
}
def code(x, y, z): return (1.0 / x) / (y * (1.0 + (z * z)))
function code(x, y, z) return Float64(Float64(1.0 / x) / Float64(y * Float64(1.0 + Float64(z * z)))) end
function tmp = code(x, y, z) tmp = (1.0 / x) / (y * (1.0 + (z * z))); end
code[x_, y_, z_] := N[(N[(1.0 / x), $MachinePrecision] / N[(y * N[(1.0 + N[(z * z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{1}{x}}{y \cdot \left(1 + z \cdot z\right)}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 7 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y z) :precision binary64 (/ (/ 1.0 x) (* y (+ 1.0 (* z z)))))
double code(double x, double y, double z) {
return (1.0 / x) / (y * (1.0 + (z * z)));
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = (1.0d0 / x) / (y * (1.0d0 + (z * z)))
end function
public static double code(double x, double y, double z) {
return (1.0 / x) / (y * (1.0 + (z * z)));
}
def code(x, y, z): return (1.0 / x) / (y * (1.0 + (z * z)))
function code(x, y, z) return Float64(Float64(1.0 / x) / Float64(y * Float64(1.0 + Float64(z * z)))) end
function tmp = code(x, y, z) tmp = (1.0 / x) / (y * (1.0 + (z * z))); end
code[x_, y_, z_] := N[(N[(1.0 / x), $MachinePrecision] / N[(y * N[(1.0 + N[(z * z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{1}{x}}{y \cdot \left(1 + z \cdot z\right)}
\end{array}
NOTE: x, y, and z should be sorted in increasing order before calling this function. (FPCore (x y z) :precision binary64 (if (<= (* z z) 4e+284) (/ (/ (/ -1.0 x) y) (- (fma z z 1.0))) (/ 1.0 (* (* (* y z) x) z))))
assert(x < y && y < z);
double code(double x, double y, double z) {
double tmp;
if ((z * z) <= 4e+284) {
tmp = ((-1.0 / x) / y) / -fma(z, z, 1.0);
} else {
tmp = 1.0 / (((y * z) * x) * z);
}
return tmp;
}
x, y, z = sort([x, y, z]) function code(x, y, z) tmp = 0.0 if (Float64(z * z) <= 4e+284) tmp = Float64(Float64(Float64(-1.0 / x) / y) / Float64(-fma(z, z, 1.0))); else tmp = Float64(1.0 / Float64(Float64(Float64(y * z) * x) * z)); end return tmp end
NOTE: x, y, and z should be sorted in increasing order before calling this function. code[x_, y_, z_] := If[LessEqual[N[(z * z), $MachinePrecision], 4e+284], N[(N[(N[(-1.0 / x), $MachinePrecision] / y), $MachinePrecision] / (-N[(z * z + 1.0), $MachinePrecision])), $MachinePrecision], N[(1.0 / N[(N[(N[(y * z), $MachinePrecision] * x), $MachinePrecision] * z), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
[x, y, z] = \mathsf{sort}([x, y, z])\\
\\
\begin{array}{l}
\mathbf{if}\;z \cdot z \leq 4 \cdot 10^{+284}:\\
\;\;\;\;\frac{\frac{\frac{-1}{x}}{y}}{-\mathsf{fma}\left(z, z, 1\right)}\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{\left(\left(y \cdot z\right) \cdot x\right) \cdot z}\\
\end{array}
\end{array}
if (*.f64 z z) < 4.00000000000000032e284Initial program 95.6%
lift-/.f64N/A
lift-*.f64N/A
associate-/r*N/A
frac-2negN/A
lower-/.f64N/A
distribute-neg-fracN/A
lower-/.f64N/A
lift-/.f64N/A
distribute-neg-fracN/A
metadata-evalN/A
lower-/.f64N/A
lower-neg.f6499.1
lift-+.f64N/A
+-commutativeN/A
lift-*.f64N/A
lower-fma.f6499.1
Applied rewrites99.1%
if 4.00000000000000032e284 < (*.f64 z z) Initial program 72.1%
Taylor expanded in z around inf
lower-/.f64N/A
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
unpow2N/A
lower-*.f6472.1
Applied rewrites72.1%
Applied rewrites71.5%
Applied rewrites97.7%
NOTE: x, y, and z should be sorted in increasing order before calling this function. (FPCore (x y z) :precision binary64 (if (<= (* z z) 2e+258) (/ 1.0 (* (* (fma z z 1.0) x) y)) (/ (/ 1.0 (* x z)) (* y z))))
assert(x < y && y < z);
double code(double x, double y, double z) {
double tmp;
if ((z * z) <= 2e+258) {
tmp = 1.0 / ((fma(z, z, 1.0) * x) * y);
} else {
tmp = (1.0 / (x * z)) / (y * z);
}
return tmp;
}
x, y, z = sort([x, y, z]) function code(x, y, z) tmp = 0.0 if (Float64(z * z) <= 2e+258) tmp = Float64(1.0 / Float64(Float64(fma(z, z, 1.0) * x) * y)); else tmp = Float64(Float64(1.0 / Float64(x * z)) / Float64(y * z)); end return tmp end
NOTE: x, y, and z should be sorted in increasing order before calling this function. code[x_, y_, z_] := If[LessEqual[N[(z * z), $MachinePrecision], 2e+258], N[(1.0 / N[(N[(N[(z * z + 1.0), $MachinePrecision] * x), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 / N[(x * z), $MachinePrecision]), $MachinePrecision] / N[(y * z), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
[x, y, z] = \mathsf{sort}([x, y, z])\\
\\
\begin{array}{l}
\mathbf{if}\;z \cdot z \leq 2 \cdot 10^{+258}:\\
\;\;\;\;\frac{1}{\left(\mathsf{fma}\left(z, z, 1\right) \cdot x\right) \cdot y}\\
\mathbf{else}:\\
\;\;\;\;\frac{\frac{1}{x \cdot z}}{y \cdot z}\\
\end{array}
\end{array}
if (*.f64 z z) < 2.00000000000000011e258Initial program 95.5%
lift-/.f64N/A
lift-*.f64N/A
associate-/r*N/A
frac-2negN/A
lower-/.f64N/A
distribute-neg-fracN/A
lower-/.f64N/A
lift-/.f64N/A
distribute-neg-fracN/A
metadata-evalN/A
lower-/.f64N/A
lower-neg.f6499.1
lift-+.f64N/A
+-commutativeN/A
lift-*.f64N/A
lower-fma.f6499.1
Applied rewrites99.1%
lift-/.f64N/A
lift-/.f64N/A
associate-/r*N/A
lift-/.f64N/A
div-invN/A
lift-/.f64N/A
neg-mul-1N/A
lift-neg.f64N/A
distribute-rgt-neg-inN/A
lift-fma.f64N/A
lift-*.f64N/A
+-commutativeN/A
lift-*.f64N/A
frac-2negN/A
clear-numN/A
lower-/.f64N/A
div-invN/A
Applied rewrites94.5%
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
lift-*.f64N/A
lower-*.f6497.1
lift-*.f64N/A
*-commutativeN/A
lower-*.f6497.1
Applied rewrites97.1%
if 2.00000000000000011e258 < (*.f64 z z) Initial program 74.6%
Taylor expanded in z around inf
lower-/.f64N/A
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
unpow2N/A
lower-*.f6474.5
Applied rewrites74.5%
Applied rewrites97.8%
Final simplification97.3%
NOTE: x, y, and z should be sorted in increasing order before calling this function. (FPCore (x y z) :precision binary64 (if (<= (* z z) 4e+284) (/ 1.0 (* (* (fma z z 1.0) x) y)) (/ 1.0 (* (* (* y z) x) z))))
assert(x < y && y < z);
double code(double x, double y, double z) {
double tmp;
if ((z * z) <= 4e+284) {
tmp = 1.0 / ((fma(z, z, 1.0) * x) * y);
} else {
tmp = 1.0 / (((y * z) * x) * z);
}
return tmp;
}
x, y, z = sort([x, y, z]) function code(x, y, z) tmp = 0.0 if (Float64(z * z) <= 4e+284) tmp = Float64(1.0 / Float64(Float64(fma(z, z, 1.0) * x) * y)); else tmp = Float64(1.0 / Float64(Float64(Float64(y * z) * x) * z)); end return tmp end
NOTE: x, y, and z should be sorted in increasing order before calling this function. code[x_, y_, z_] := If[LessEqual[N[(z * z), $MachinePrecision], 4e+284], N[(1.0 / N[(N[(N[(z * z + 1.0), $MachinePrecision] * x), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[(N[(y * z), $MachinePrecision] * x), $MachinePrecision] * z), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
[x, y, z] = \mathsf{sort}([x, y, z])\\
\\
\begin{array}{l}
\mathbf{if}\;z \cdot z \leq 4 \cdot 10^{+284}:\\
\;\;\;\;\frac{1}{\left(\mathsf{fma}\left(z, z, 1\right) \cdot x\right) \cdot y}\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{\left(\left(y \cdot z\right) \cdot x\right) \cdot z}\\
\end{array}
\end{array}
if (*.f64 z z) < 4.00000000000000032e284Initial program 95.6%
lift-/.f64N/A
lift-*.f64N/A
associate-/r*N/A
frac-2negN/A
lower-/.f64N/A
distribute-neg-fracN/A
lower-/.f64N/A
lift-/.f64N/A
distribute-neg-fracN/A
metadata-evalN/A
lower-/.f64N/A
lower-neg.f6499.1
lift-+.f64N/A
+-commutativeN/A
lift-*.f64N/A
lower-fma.f6499.1
Applied rewrites99.1%
lift-/.f64N/A
lift-/.f64N/A
associate-/r*N/A
lift-/.f64N/A
div-invN/A
lift-/.f64N/A
neg-mul-1N/A
lift-neg.f64N/A
distribute-rgt-neg-inN/A
lift-fma.f64N/A
lift-*.f64N/A
+-commutativeN/A
lift-*.f64N/A
frac-2negN/A
clear-numN/A
lower-/.f64N/A
div-invN/A
Applied rewrites94.7%
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
lift-*.f64N/A
lower-*.f6497.2
lift-*.f64N/A
*-commutativeN/A
lower-*.f6497.2
Applied rewrites97.2%
if 4.00000000000000032e284 < (*.f64 z z) Initial program 72.1%
Taylor expanded in z around inf
lower-/.f64N/A
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
unpow2N/A
lower-*.f6472.1
Applied rewrites72.1%
Applied rewrites71.5%
Applied rewrites97.7%
Final simplification97.3%
NOTE: x, y, and z should be sorted in increasing order before calling this function. (FPCore (x y z) :precision binary64 (if (<= (* z z) 5e-8) (/ (/ -1.0 y) (- x)) (/ 1.0 (* (* y z) (* x z)))))
assert(x < y && y < z);
double code(double x, double y, double z) {
double tmp;
if ((z * z) <= 5e-8) {
tmp = (-1.0 / y) / -x;
} else {
tmp = 1.0 / ((y * z) * (x * z));
}
return tmp;
}
NOTE: x, y, and z should be sorted in increasing order before calling this function.
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 * z) <= 5d-8) then
tmp = ((-1.0d0) / y) / -x
else
tmp = 1.0d0 / ((y * z) * (x * z))
end if
code = tmp
end function
assert x < y && y < z;
public static double code(double x, double y, double z) {
double tmp;
if ((z * z) <= 5e-8) {
tmp = (-1.0 / y) / -x;
} else {
tmp = 1.0 / ((y * z) * (x * z));
}
return tmp;
}
[x, y, z] = sort([x, y, z]) def code(x, y, z): tmp = 0 if (z * z) <= 5e-8: tmp = (-1.0 / y) / -x else: tmp = 1.0 / ((y * z) * (x * z)) return tmp
x, y, z = sort([x, y, z]) function code(x, y, z) tmp = 0.0 if (Float64(z * z) <= 5e-8) tmp = Float64(Float64(-1.0 / y) / Float64(-x)); else tmp = Float64(1.0 / Float64(Float64(y * z) * Float64(x * z))); end return tmp end
x, y, z = num2cell(sort([x, y, z])){:}
function tmp_2 = code(x, y, z)
tmp = 0.0;
if ((z * z) <= 5e-8)
tmp = (-1.0 / y) / -x;
else
tmp = 1.0 / ((y * z) * (x * z));
end
tmp_2 = tmp;
end
NOTE: x, y, and z should be sorted in increasing order before calling this function. code[x_, y_, z_] := If[LessEqual[N[(z * z), $MachinePrecision], 5e-8], N[(N[(-1.0 / y), $MachinePrecision] / (-x)), $MachinePrecision], N[(1.0 / N[(N[(y * z), $MachinePrecision] * N[(x * z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
[x, y, z] = \mathsf{sort}([x, y, z])\\
\\
\begin{array}{l}
\mathbf{if}\;z \cdot z \leq 5 \cdot 10^{-8}:\\
\;\;\;\;\frac{\frac{-1}{y}}{-x}\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{\left(y \cdot z\right) \cdot \left(x \cdot z\right)}\\
\end{array}
\end{array}
if (*.f64 z z) < 4.9999999999999998e-8Initial program 99.7%
Taylor expanded in z around 0
associate-/r*N/A
lower-/.f64N/A
lower-/.f6499.1
Applied rewrites99.1%
Applied rewrites99.1%
if 4.9999999999999998e-8 < (*.f64 z z) Initial program 78.0%
Taylor expanded in z around inf
lower-/.f64N/A
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
unpow2N/A
lower-*.f6475.8
Applied rewrites75.8%
Applied rewrites94.0%
Final simplification96.6%
NOTE: x, y, and z should be sorted in increasing order before calling this function. (FPCore (x y z) :precision binary64 (/ (/ -1.0 y) (- x)))
assert(x < y && y < z);
double code(double x, double y, double z) {
return (-1.0 / y) / -x;
}
NOTE: x, y, and z should be sorted in increasing order before calling this function.
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = ((-1.0d0) / y) / -x
end function
assert x < y && y < z;
public static double code(double x, double y, double z) {
return (-1.0 / y) / -x;
}
[x, y, z] = sort([x, y, z]) def code(x, y, z): return (-1.0 / y) / -x
x, y, z = sort([x, y, z]) function code(x, y, z) return Float64(Float64(-1.0 / y) / Float64(-x)) end
x, y, z = num2cell(sort([x, y, z])){:}
function tmp = code(x, y, z)
tmp = (-1.0 / y) / -x;
end
NOTE: x, y, and z should be sorted in increasing order before calling this function. code[x_, y_, z_] := N[(N[(-1.0 / y), $MachinePrecision] / (-x)), $MachinePrecision]
\begin{array}{l}
[x, y, z] = \mathsf{sort}([x, y, z])\\
\\
\frac{\frac{-1}{y}}{-x}
\end{array}
Initial program 89.2%
Taylor expanded in z around 0
associate-/r*N/A
lower-/.f64N/A
lower-/.f6459.5
Applied rewrites59.5%
Applied rewrites59.5%
NOTE: x, y, and z should be sorted in increasing order before calling this function. (FPCore (x y z) :precision binary64 (/ (/ 1.0 x) y))
assert(x < y && y < z);
double code(double x, double y, double z) {
return (1.0 / x) / y;
}
NOTE: x, y, and z should be sorted in increasing order before calling this function.
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = (1.0d0 / x) / y
end function
assert x < y && y < z;
public static double code(double x, double y, double z) {
return (1.0 / x) / y;
}
[x, y, z] = sort([x, y, z]) def code(x, y, z): return (1.0 / x) / y
x, y, z = sort([x, y, z]) function code(x, y, z) return Float64(Float64(1.0 / x) / y) end
x, y, z = num2cell(sort([x, y, z])){:}
function tmp = code(x, y, z)
tmp = (1.0 / x) / y;
end
NOTE: x, y, and z should be sorted in increasing order before calling this function. code[x_, y_, z_] := N[(N[(1.0 / x), $MachinePrecision] / y), $MachinePrecision]
\begin{array}{l}
[x, y, z] = \mathsf{sort}([x, y, z])\\
\\
\frac{\frac{1}{x}}{y}
\end{array}
Initial program 89.2%
Taylor expanded in z around 0
associate-/r*N/A
lower-/.f64N/A
lower-/.f6459.5
Applied rewrites59.5%
NOTE: x, y, and z should be sorted in increasing order before calling this function. (FPCore (x y z) :precision binary64 (/ 1.0 (* y x)))
assert(x < y && y < z);
double code(double x, double y, double z) {
return 1.0 / (y * x);
}
NOTE: x, y, and z should be sorted in increasing order before calling this function.
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = 1.0d0 / (y * x)
end function
assert x < y && y < z;
public static double code(double x, double y, double z) {
return 1.0 / (y * x);
}
[x, y, z] = sort([x, y, z]) def code(x, y, z): return 1.0 / (y * x)
x, y, z = sort([x, y, z]) function code(x, y, z) return Float64(1.0 / Float64(y * x)) end
x, y, z = num2cell(sort([x, y, z])){:}
function tmp = code(x, y, z)
tmp = 1.0 / (y * x);
end
NOTE: x, y, and z should be sorted in increasing order before calling this function. code[x_, y_, z_] := N[(1.0 / N[(y * x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
[x, y, z] = \mathsf{sort}([x, y, z])\\
\\
\frac{1}{y \cdot x}
\end{array}
Initial program 89.2%
Taylor expanded in z around 0
associate-/r*N/A
lower-/.f64N/A
lower-/.f6459.5
Applied rewrites59.5%
Applied rewrites59.2%
(FPCore (x y z)
:precision binary64
(let* ((t_0 (+ 1.0 (* z z))) (t_1 (* y t_0)) (t_2 (/ (/ 1.0 y) (* t_0 x))))
(if (< t_1 (- INFINITY))
t_2
(if (< t_1 8.680743250567252e+305) (/ (/ 1.0 x) (* t_0 y)) t_2))))
double code(double x, double y, double z) {
double t_0 = 1.0 + (z * z);
double t_1 = y * t_0;
double t_2 = (1.0 / y) / (t_0 * x);
double tmp;
if (t_1 < -((double) INFINITY)) {
tmp = t_2;
} else if (t_1 < 8.680743250567252e+305) {
tmp = (1.0 / x) / (t_0 * y);
} else {
tmp = t_2;
}
return tmp;
}
public static double code(double x, double y, double z) {
double t_0 = 1.0 + (z * z);
double t_1 = y * t_0;
double t_2 = (1.0 / y) / (t_0 * x);
double tmp;
if (t_1 < -Double.POSITIVE_INFINITY) {
tmp = t_2;
} else if (t_1 < 8.680743250567252e+305) {
tmp = (1.0 / x) / (t_0 * y);
} else {
tmp = t_2;
}
return tmp;
}
def code(x, y, z): t_0 = 1.0 + (z * z) t_1 = y * t_0 t_2 = (1.0 / y) / (t_0 * x) tmp = 0 if t_1 < -math.inf: tmp = t_2 elif t_1 < 8.680743250567252e+305: tmp = (1.0 / x) / (t_0 * y) else: tmp = t_2 return tmp
function code(x, y, z) t_0 = Float64(1.0 + Float64(z * z)) t_1 = Float64(y * t_0) t_2 = Float64(Float64(1.0 / y) / Float64(t_0 * x)) tmp = 0.0 if (t_1 < Float64(-Inf)) tmp = t_2; elseif (t_1 < 8.680743250567252e+305) tmp = Float64(Float64(1.0 / x) / Float64(t_0 * y)); else tmp = t_2; end return tmp end
function tmp_2 = code(x, y, z) t_0 = 1.0 + (z * z); t_1 = y * t_0; t_2 = (1.0 / y) / (t_0 * x); tmp = 0.0; if (t_1 < -Inf) tmp = t_2; elseif (t_1 < 8.680743250567252e+305) tmp = (1.0 / x) / (t_0 * y); else tmp = t_2; end tmp_2 = tmp; end
code[x_, y_, z_] := Block[{t$95$0 = N[(1.0 + N[(z * z), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(y * t$95$0), $MachinePrecision]}, Block[{t$95$2 = N[(N[(1.0 / y), $MachinePrecision] / N[(t$95$0 * x), $MachinePrecision]), $MachinePrecision]}, If[Less[t$95$1, (-Infinity)], t$95$2, If[Less[t$95$1, 8.680743250567252e+305], N[(N[(1.0 / x), $MachinePrecision] / N[(t$95$0 * y), $MachinePrecision]), $MachinePrecision], t$95$2]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := 1 + z \cdot z\\
t_1 := y \cdot t\_0\\
t_2 := \frac{\frac{1}{y}}{t\_0 \cdot x}\\
\mathbf{if}\;t\_1 < -\infty:\\
\;\;\;\;t\_2\\
\mathbf{elif}\;t\_1 < 8.680743250567252 \cdot 10^{+305}:\\
\;\;\;\;\frac{\frac{1}{x}}{t\_0 \cdot y}\\
\mathbf{else}:\\
\;\;\;\;t\_2\\
\end{array}
\end{array}
herbie shell --seed 2024296
(FPCore (x y z)
:name "Statistics.Distribution.CauchyLorentz:$cdensity from math-functions-0.1.5.2"
:precision binary64
:alt
(! :herbie-platform default (if (< (* y (+ 1 (* z z))) -inf.0) (/ (/ 1 y) (* (+ 1 (* z z)) x)) (if (< (* y (+ 1 (* z z))) 868074325056725200000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000) (/ (/ 1 x) (* (+ 1 (* z z)) y)) (/ (/ 1 y) (* (+ 1 (* z z)) x)))))
(/ (/ 1.0 x) (* y (+ 1.0 (* z z)))))