
(FPCore (x y z) :precision binary64 (* 2.0 (sqrt (+ (+ (* x y) (* x z)) (* y z)))))
double code(double x, double y, double z) {
return 2.0 * sqrt((((x * y) + (x * z)) + (y * z)));
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = 2.0d0 * sqrt((((x * y) + (x * z)) + (y * z)))
end function
public static double code(double x, double y, double z) {
return 2.0 * Math.sqrt((((x * y) + (x * z)) + (y * z)));
}
def code(x, y, z): return 2.0 * math.sqrt((((x * y) + (x * z)) + (y * z)))
function code(x, y, z) return Float64(2.0 * sqrt(Float64(Float64(Float64(x * y) + Float64(x * z)) + Float64(y * z)))) end
function tmp = code(x, y, z) tmp = 2.0 * sqrt((((x * y) + (x * z)) + (y * z))); end
code[x_, y_, z_] := N[(2.0 * N[Sqrt[N[(N[(N[(x * y), $MachinePrecision] + N[(x * z), $MachinePrecision]), $MachinePrecision] + N[(y * z), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
2 \cdot \sqrt{\left(x \cdot y + x \cdot z\right) + y \cdot z}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 6 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y z) :precision binary64 (* 2.0 (sqrt (+ (+ (* x y) (* x z)) (* y z)))))
double code(double x, double y, double z) {
return 2.0 * sqrt((((x * y) + (x * z)) + (y * z)));
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = 2.0d0 * sqrt((((x * y) + (x * z)) + (y * z)))
end function
public static double code(double x, double y, double z) {
return 2.0 * Math.sqrt((((x * y) + (x * z)) + (y * z)));
}
def code(x, y, z): return 2.0 * math.sqrt((((x * y) + (x * z)) + (y * z)))
function code(x, y, z) return Float64(2.0 * sqrt(Float64(Float64(Float64(x * y) + Float64(x * z)) + Float64(y * z)))) end
function tmp = code(x, y, z) tmp = 2.0 * sqrt((((x * y) + (x * z)) + (y * z))); end
code[x_, y_, z_] := N[(2.0 * N[Sqrt[N[(N[(N[(x * y), $MachinePrecision] + N[(x * z), $MachinePrecision]), $MachinePrecision] + N[(y * z), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
2 \cdot \sqrt{\left(x \cdot y + x \cdot z\right) + y \cdot z}
\end{array}
NOTE: x, y, and z should be sorted in increasing order before calling this function.
(FPCore (x y z)
:precision binary64
(if (<= y 5e+29)
(* (sqrt (+ (* z y) (+ (* z x) (* x y)))) 2.0)
(*
(fma
(sqrt (/ (/ 1.0 (+ x y)) (pow z 3.0)))
(* x y)
(* (sqrt (/ (+ x y) z)) 2.0))
z)))assert(x < y && y < z);
double code(double x, double y, double z) {
double tmp;
if (y <= 5e+29) {
tmp = sqrt(((z * y) + ((z * x) + (x * y)))) * 2.0;
} else {
tmp = fma(sqrt(((1.0 / (x + y)) / pow(z, 3.0))), (x * y), (sqrt(((x + y) / z)) * 2.0)) * z;
}
return tmp;
}
x, y, z = sort([x, y, z]) function code(x, y, z) tmp = 0.0 if (y <= 5e+29) tmp = Float64(sqrt(Float64(Float64(z * y) + Float64(Float64(z * x) + Float64(x * y)))) * 2.0); else tmp = Float64(fma(sqrt(Float64(Float64(1.0 / Float64(x + y)) / (z ^ 3.0))), Float64(x * y), Float64(sqrt(Float64(Float64(x + y) / z)) * 2.0)) * 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[y, 5e+29], N[(N[Sqrt[N[(N[(z * y), $MachinePrecision] + N[(N[(z * x), $MachinePrecision] + N[(x * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision], N[(N[(N[Sqrt[N[(N[(1.0 / N[(x + y), $MachinePrecision]), $MachinePrecision] / N[Power[z, 3.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[(x * y), $MachinePrecision] + N[(N[Sqrt[N[(N[(x + y), $MachinePrecision] / z), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]), $MachinePrecision] * z), $MachinePrecision]]
\begin{array}{l}
[x, y, z] = \mathsf{sort}([x, y, z])\\
\\
\begin{array}{l}
\mathbf{if}\;y \leq 5 \cdot 10^{+29}:\\
\;\;\;\;\sqrt{z \cdot y + \left(z \cdot x + x \cdot y\right)} \cdot 2\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\sqrt{\frac{\frac{1}{x + y}}{{z}^{3}}}, x \cdot y, \sqrt{\frac{x + y}{z}} \cdot 2\right) \cdot z\\
\end{array}
\end{array}
if y < 5.0000000000000001e29Initial program 72.6%
if 5.0000000000000001e29 < y Initial program 62.3%
Taylor expanded in z around inf
*-commutativeN/A
lower-*.f64N/A
Applied rewrites35.4%
Final simplification64.2%
NOTE: x, y, and z should be sorted in increasing order before calling this function. (FPCore (x y z) :precision binary64 (* (sqrt (+ (* z y) (+ (* z x) (* x y)))) 2.0))
assert(x < y && y < z);
double code(double x, double y, double z) {
return sqrt(((z * y) + ((z * x) + (x * y)))) * 2.0;
}
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 = sqrt(((z * y) + ((z * x) + (x * y)))) * 2.0d0
end function
assert x < y && y < z;
public static double code(double x, double y, double z) {
return Math.sqrt(((z * y) + ((z * x) + (x * y)))) * 2.0;
}
[x, y, z] = sort([x, y, z]) def code(x, y, z): return math.sqrt(((z * y) + ((z * x) + (x * y)))) * 2.0
x, y, z = sort([x, y, z]) function code(x, y, z) return Float64(sqrt(Float64(Float64(z * y) + Float64(Float64(z * x) + Float64(x * y)))) * 2.0) end
x, y, z = num2cell(sort([x, y, z])){:}
function tmp = code(x, y, z)
tmp = sqrt(((z * y) + ((z * x) + (x * y)))) * 2.0;
end
NOTE: x, y, and z should be sorted in increasing order before calling this function. code[x_, y_, z_] := N[(N[Sqrt[N[(N[(z * y), $MachinePrecision] + N[(N[(z * x), $MachinePrecision] + N[(x * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]
\begin{array}{l}
[x, y, z] = \mathsf{sort}([x, y, z])\\
\\
\sqrt{z \cdot y + \left(z \cdot x + x \cdot y\right)} \cdot 2
\end{array}
Initial program 70.3%
Final simplification70.3%
NOTE: x, y, and z should be sorted in increasing order before calling this function. (FPCore (x y z) :precision binary64 (if (<= y -1e-302) (* (sqrt (* (+ z y) x)) 2.0) (* (sqrt (* (+ x y) z)) 2.0)))
assert(x < y && y < z);
double code(double x, double y, double z) {
double tmp;
if (y <= -1e-302) {
tmp = sqrt(((z + y) * x)) * 2.0;
} else {
tmp = sqrt(((x + y) * z)) * 2.0;
}
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 (y <= (-1d-302)) then
tmp = sqrt(((z + y) * x)) * 2.0d0
else
tmp = sqrt(((x + y) * z)) * 2.0d0
end if
code = tmp
end function
assert x < y && y < z;
public static double code(double x, double y, double z) {
double tmp;
if (y <= -1e-302) {
tmp = Math.sqrt(((z + y) * x)) * 2.0;
} else {
tmp = Math.sqrt(((x + y) * z)) * 2.0;
}
return tmp;
}
[x, y, z] = sort([x, y, z]) def code(x, y, z): tmp = 0 if y <= -1e-302: tmp = math.sqrt(((z + y) * x)) * 2.0 else: tmp = math.sqrt(((x + y) * z)) * 2.0 return tmp
x, y, z = sort([x, y, z]) function code(x, y, z) tmp = 0.0 if (y <= -1e-302) tmp = Float64(sqrt(Float64(Float64(z + y) * x)) * 2.0); else tmp = Float64(sqrt(Float64(Float64(x + y) * z)) * 2.0); end return tmp end
x, y, z = num2cell(sort([x, y, z])){:}
function tmp_2 = code(x, y, z)
tmp = 0.0;
if (y <= -1e-302)
tmp = sqrt(((z + y) * x)) * 2.0;
else
tmp = sqrt(((x + y) * z)) * 2.0;
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[y, -1e-302], N[(N[Sqrt[N[(N[(z + y), $MachinePrecision] * x), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision], N[(N[Sqrt[N[(N[(x + y), $MachinePrecision] * z), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]]
\begin{array}{l}
[x, y, z] = \mathsf{sort}([x, y, z])\\
\\
\begin{array}{l}
\mathbf{if}\;y \leq -1 \cdot 10^{-302}:\\
\;\;\;\;\sqrt{\left(z + y\right) \cdot x} \cdot 2\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\left(x + y\right) \cdot z} \cdot 2\\
\end{array}
\end{array}
if y < -9.9999999999999996e-303Initial program 72.0%
Taylor expanded in x around inf
*-commutativeN/A
lower-*.f64N/A
+-commutativeN/A
lower-+.f6446.0
Applied rewrites46.0%
if -9.9999999999999996e-303 < y Initial program 68.3%
Taylor expanded in z around inf
*-commutativeN/A
lower-*.f64N/A
+-commutativeN/A
lower-+.f6442.1
Applied rewrites42.1%
Final simplification44.1%
NOTE: x, y, and z should be sorted in increasing order before calling this function. (FPCore (x y z) :precision binary64 (if (<= y -1.3e-289) (* (sqrt (* x y)) 2.0) (* (sqrt (* (+ x y) z)) 2.0)))
assert(x < y && y < z);
double code(double x, double y, double z) {
double tmp;
if (y <= -1.3e-289) {
tmp = sqrt((x * y)) * 2.0;
} else {
tmp = sqrt(((x + y) * z)) * 2.0;
}
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 (y <= (-1.3d-289)) then
tmp = sqrt((x * y)) * 2.0d0
else
tmp = sqrt(((x + y) * z)) * 2.0d0
end if
code = tmp
end function
assert x < y && y < z;
public static double code(double x, double y, double z) {
double tmp;
if (y <= -1.3e-289) {
tmp = Math.sqrt((x * y)) * 2.0;
} else {
tmp = Math.sqrt(((x + y) * z)) * 2.0;
}
return tmp;
}
[x, y, z] = sort([x, y, z]) def code(x, y, z): tmp = 0 if y <= -1.3e-289: tmp = math.sqrt((x * y)) * 2.0 else: tmp = math.sqrt(((x + y) * z)) * 2.0 return tmp
x, y, z = sort([x, y, z]) function code(x, y, z) tmp = 0.0 if (y <= -1.3e-289) tmp = Float64(sqrt(Float64(x * y)) * 2.0); else tmp = Float64(sqrt(Float64(Float64(x + y) * z)) * 2.0); end return tmp end
x, y, z = num2cell(sort([x, y, z])){:}
function tmp_2 = code(x, y, z)
tmp = 0.0;
if (y <= -1.3e-289)
tmp = sqrt((x * y)) * 2.0;
else
tmp = sqrt(((x + y) * z)) * 2.0;
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[y, -1.3e-289], N[(N[Sqrt[N[(x * y), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision], N[(N[Sqrt[N[(N[(x + y), $MachinePrecision] * z), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]]
\begin{array}{l}
[x, y, z] = \mathsf{sort}([x, y, z])\\
\\
\begin{array}{l}
\mathbf{if}\;y \leq -1.3 \cdot 10^{-289}:\\
\;\;\;\;\sqrt{x \cdot y} \cdot 2\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\left(x + y\right) \cdot z} \cdot 2\\
\end{array}
\end{array}
if y < -1.2999999999999999e-289Initial program 71.4%
Taylor expanded in z around 0
*-commutativeN/A
lower-*.f6426.8
Applied rewrites26.8%
if -1.2999999999999999e-289 < y Initial program 69.1%
Taylor expanded in z around inf
*-commutativeN/A
lower-*.f64N/A
+-commutativeN/A
lower-+.f6443.5
Applied rewrites43.5%
Final simplification34.8%
NOTE: x, y, and z should be sorted in increasing order before calling this function. (FPCore (x y z) :precision binary64 (if (<= y -2e-310) (* (sqrt (* x y)) 2.0) (* (sqrt (* z y)) 2.0)))
assert(x < y && y < z);
double code(double x, double y, double z) {
double tmp;
if (y <= -2e-310) {
tmp = sqrt((x * y)) * 2.0;
} else {
tmp = sqrt((z * y)) * 2.0;
}
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 (y <= (-2d-310)) then
tmp = sqrt((x * y)) * 2.0d0
else
tmp = sqrt((z * y)) * 2.0d0
end if
code = tmp
end function
assert x < y && y < z;
public static double code(double x, double y, double z) {
double tmp;
if (y <= -2e-310) {
tmp = Math.sqrt((x * y)) * 2.0;
} else {
tmp = Math.sqrt((z * y)) * 2.0;
}
return tmp;
}
[x, y, z] = sort([x, y, z]) def code(x, y, z): tmp = 0 if y <= -2e-310: tmp = math.sqrt((x * y)) * 2.0 else: tmp = math.sqrt((z * y)) * 2.0 return tmp
x, y, z = sort([x, y, z]) function code(x, y, z) tmp = 0.0 if (y <= -2e-310) tmp = Float64(sqrt(Float64(x * y)) * 2.0); else tmp = Float64(sqrt(Float64(z * y)) * 2.0); end return tmp end
x, y, z = num2cell(sort([x, y, z])){:}
function tmp_2 = code(x, y, z)
tmp = 0.0;
if (y <= -2e-310)
tmp = sqrt((x * y)) * 2.0;
else
tmp = sqrt((z * y)) * 2.0;
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[y, -2e-310], N[(N[Sqrt[N[(x * y), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision], N[(N[Sqrt[N[(z * y), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]]
\begin{array}{l}
[x, y, z] = \mathsf{sort}([x, y, z])\\
\\
\begin{array}{l}
\mathbf{if}\;y \leq -2 \cdot 10^{-310}:\\
\;\;\;\;\sqrt{x \cdot y} \cdot 2\\
\mathbf{else}:\\
\;\;\;\;\sqrt{z \cdot y} \cdot 2\\
\end{array}
\end{array}
if y < -1.999999999999994e-310Initial program 71.5%
Taylor expanded in z around 0
*-commutativeN/A
lower-*.f6426.2
Applied rewrites26.2%
if -1.999999999999994e-310 < y Initial program 68.9%
Taylor expanded in x around 0
*-commutativeN/A
lower-*.f6425.6
Applied rewrites25.6%
Final simplification25.9%
NOTE: x, y, and z should be sorted in increasing order before calling this function. (FPCore (x y z) :precision binary64 (* (sqrt (* x y)) 2.0))
assert(x < y && y < z);
double code(double x, double y, double z) {
return sqrt((x * y)) * 2.0;
}
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 = sqrt((x * y)) * 2.0d0
end function
assert x < y && y < z;
public static double code(double x, double y, double z) {
return Math.sqrt((x * y)) * 2.0;
}
[x, y, z] = sort([x, y, z]) def code(x, y, z): return math.sqrt((x * y)) * 2.0
x, y, z = sort([x, y, z]) function code(x, y, z) return Float64(sqrt(Float64(x * y)) * 2.0) end
x, y, z = num2cell(sort([x, y, z])){:}
function tmp = code(x, y, z)
tmp = sqrt((x * y)) * 2.0;
end
NOTE: x, y, and z should be sorted in increasing order before calling this function. code[x_, y_, z_] := N[(N[Sqrt[N[(x * y), $MachinePrecision]], $MachinePrecision] * 2.0), $MachinePrecision]
\begin{array}{l}
[x, y, z] = \mathsf{sort}([x, y, z])\\
\\
\sqrt{x \cdot y} \cdot 2
\end{array}
Initial program 70.3%
Taylor expanded in z around 0
*-commutativeN/A
lower-*.f6427.7
Applied rewrites27.7%
Final simplification27.7%
(FPCore (x y z)
:precision binary64
(let* ((t_0
(+
(* 0.25 (* (* (pow y -0.75) (* (pow z -0.75) x)) (+ y z)))
(* (pow z 0.25) (pow y 0.25)))))
(if (< z 7.636950090573675e+176)
(* 2.0 (sqrt (+ (* (+ x y) z) (* x y))))
(* (* t_0 t_0) 2.0))))
double code(double x, double y, double z) {
double t_0 = (0.25 * ((pow(y, -0.75) * (pow(z, -0.75) * x)) * (y + z))) + (pow(z, 0.25) * pow(y, 0.25));
double tmp;
if (z < 7.636950090573675e+176) {
tmp = 2.0 * sqrt((((x + y) * z) + (x * y)));
} else {
tmp = (t_0 * t_0) * 2.0;
}
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 = (0.25d0 * (((y ** (-0.75d0)) * ((z ** (-0.75d0)) * x)) * (y + z))) + ((z ** 0.25d0) * (y ** 0.25d0))
if (z < 7.636950090573675d+176) then
tmp = 2.0d0 * sqrt((((x + y) * z) + (x * y)))
else
tmp = (t_0 * t_0) * 2.0d0
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double t_0 = (0.25 * ((Math.pow(y, -0.75) * (Math.pow(z, -0.75) * x)) * (y + z))) + (Math.pow(z, 0.25) * Math.pow(y, 0.25));
double tmp;
if (z < 7.636950090573675e+176) {
tmp = 2.0 * Math.sqrt((((x + y) * z) + (x * y)));
} else {
tmp = (t_0 * t_0) * 2.0;
}
return tmp;
}
def code(x, y, z): t_0 = (0.25 * ((math.pow(y, -0.75) * (math.pow(z, -0.75) * x)) * (y + z))) + (math.pow(z, 0.25) * math.pow(y, 0.25)) tmp = 0 if z < 7.636950090573675e+176: tmp = 2.0 * math.sqrt((((x + y) * z) + (x * y))) else: tmp = (t_0 * t_0) * 2.0 return tmp
function code(x, y, z) t_0 = Float64(Float64(0.25 * Float64(Float64((y ^ -0.75) * Float64((z ^ -0.75) * x)) * Float64(y + z))) + Float64((z ^ 0.25) * (y ^ 0.25))) tmp = 0.0 if (z < 7.636950090573675e+176) tmp = Float64(2.0 * sqrt(Float64(Float64(Float64(x + y) * z) + Float64(x * y)))); else tmp = Float64(Float64(t_0 * t_0) * 2.0); end return tmp end
function tmp_2 = code(x, y, z) t_0 = (0.25 * (((y ^ -0.75) * ((z ^ -0.75) * x)) * (y + z))) + ((z ^ 0.25) * (y ^ 0.25)); tmp = 0.0; if (z < 7.636950090573675e+176) tmp = 2.0 * sqrt((((x + y) * z) + (x * y))); else tmp = (t_0 * t_0) * 2.0; end tmp_2 = tmp; end
code[x_, y_, z_] := Block[{t$95$0 = N[(N[(0.25 * N[(N[(N[Power[y, -0.75], $MachinePrecision] * N[(N[Power[z, -0.75], $MachinePrecision] * x), $MachinePrecision]), $MachinePrecision] * N[(y + z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[Power[z, 0.25], $MachinePrecision] * N[Power[y, 0.25], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[Less[z, 7.636950090573675e+176], N[(2.0 * N[Sqrt[N[(N[(N[(x + y), $MachinePrecision] * z), $MachinePrecision] + N[(x * y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(N[(t$95$0 * t$95$0), $MachinePrecision] * 2.0), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := 0.25 \cdot \left(\left({y}^{-0.75} \cdot \left({z}^{-0.75} \cdot x\right)\right) \cdot \left(y + z\right)\right) + {z}^{0.25} \cdot {y}^{0.25}\\
\mathbf{if}\;z < 7.636950090573675 \cdot 10^{+176}:\\
\;\;\;\;2 \cdot \sqrt{\left(x + y\right) \cdot z + x \cdot y}\\
\mathbf{else}:\\
\;\;\;\;\left(t\_0 \cdot t\_0\right) \cdot 2\\
\end{array}
\end{array}
herbie shell --seed 2024248
(FPCore (x y z)
:name "Diagrams.TwoD.Apollonian:descartes from diagrams-contrib-1.3.0.5"
:precision binary64
:alt
(! :herbie-platform default (if (< z 763695009057367500000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000) (* 2 (sqrt (+ (* (+ x y) z) (* x y)))) (* (* (+ (* 1/4 (* (* (pow y -3/4) (* (pow z -3/4) x)) (+ y z))) (* (pow z 1/4) (pow y 1/4))) (+ (* 1/4 (* (* (pow y -3/4) (* (pow z -3/4) x)) (+ y z))) (* (pow z 1/4) (pow y 1/4)))) 2)))
(* 2.0 (sqrt (+ (+ (* x y) (* x z)) (* y z)))))