
(FPCore (x) :precision binary64 (sqrt (/ (- (exp (* 2.0 x)) 1.0) (- (exp x) 1.0))))
double code(double x) {
return sqrt(((exp((2.0 * x)) - 1.0) / (exp(x) - 1.0)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = sqrt(((exp((2.0d0 * x)) - 1.0d0) / (exp(x) - 1.0d0)))
end function
public static double code(double x) {
return Math.sqrt(((Math.exp((2.0 * x)) - 1.0) / (Math.exp(x) - 1.0)));
}
def code(x): return math.sqrt(((math.exp((2.0 * x)) - 1.0) / (math.exp(x) - 1.0)))
function code(x) return sqrt(Float64(Float64(exp(Float64(2.0 * x)) - 1.0) / Float64(exp(x) - 1.0))) end
function tmp = code(x) tmp = sqrt(((exp((2.0 * x)) - 1.0) / (exp(x) - 1.0))); end
code[x_] := N[Sqrt[N[(N[(N[Exp[N[(2.0 * x), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision] / N[(N[Exp[x], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 10 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (sqrt (/ (- (exp (* 2.0 x)) 1.0) (- (exp x) 1.0))))
double code(double x) {
return sqrt(((exp((2.0 * x)) - 1.0) / (exp(x) - 1.0)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = sqrt(((exp((2.0d0 * x)) - 1.0d0) / (exp(x) - 1.0d0)))
end function
public static double code(double x) {
return Math.sqrt(((Math.exp((2.0 * x)) - 1.0) / (Math.exp(x) - 1.0)));
}
def code(x): return math.sqrt(((math.exp((2.0 * x)) - 1.0) / (math.exp(x) - 1.0)))
function code(x) return sqrt(Float64(Float64(exp(Float64(2.0 * x)) - 1.0) / Float64(exp(x) - 1.0))) end
function tmp = code(x) tmp = sqrt(((exp((2.0 * x)) - 1.0) / (exp(x) - 1.0))); end
code[x_] := N[Sqrt[N[(N[(N[Exp[N[(2.0 * x), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision] / N[(N[Exp[x], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}
\end{array}
(FPCore (x) :precision binary64 (sqrt (+ 1.0 (exp x))))
double code(double x) {
return sqrt((1.0 + exp(x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = sqrt((1.0d0 + exp(x)))
end function
public static double code(double x) {
return Math.sqrt((1.0 + Math.exp(x)));
}
def code(x): return math.sqrt((1.0 + math.exp(x)))
function code(x) return sqrt(Float64(1.0 + exp(x))) end
function tmp = code(x) tmp = sqrt((1.0 + exp(x))); end
code[x_] := N[Sqrt[N[(1.0 + N[Exp[x], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{1 + e^{x}}
\end{array}
Initial program 30.2%
*-commutative30.2%
exp-lft-sqr30.5%
difference-of-sqr-131.2%
associate-/l*31.2%
*-inverses100.0%
/-rgt-identity100.0%
+-commutative100.0%
Simplified100.0%
Final simplification100.0%
(FPCore (x) :precision binary64 (if (<= x -4.2) (+ 1.0 (/ 1.0 x)) (hypot 1.0 (+ 1.0 (* x (+ 0.5 (* x 0.125)))))))
double code(double x) {
double tmp;
if (x <= -4.2) {
tmp = 1.0 + (1.0 / x);
} else {
tmp = hypot(1.0, (1.0 + (x * (0.5 + (x * 0.125)))));
}
return tmp;
}
public static double code(double x) {
double tmp;
if (x <= -4.2) {
tmp = 1.0 + (1.0 / x);
} else {
tmp = Math.hypot(1.0, (1.0 + (x * (0.5 + (x * 0.125)))));
}
return tmp;
}
def code(x): tmp = 0 if x <= -4.2: tmp = 1.0 + (1.0 / x) else: tmp = math.hypot(1.0, (1.0 + (x * (0.5 + (x * 0.125))))) return tmp
function code(x) tmp = 0.0 if (x <= -4.2) tmp = Float64(1.0 + Float64(1.0 / x)); else tmp = hypot(1.0, Float64(1.0 + Float64(x * Float64(0.5 + Float64(x * 0.125))))); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= -4.2) tmp = 1.0 + (1.0 / x); else tmp = hypot(1.0, (1.0 + (x * (0.5 + (x * 0.125))))); end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, -4.2], N[(1.0 + N[(1.0 / x), $MachinePrecision]), $MachinePrecision], N[Sqrt[1.0 ^ 2 + N[(1.0 + N[(x * N[(0.5 + N[(x * 0.125), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -4.2:\\
\;\;\;\;1 + \frac{1}{x}\\
\mathbf{else}:\\
\;\;\;\;\mathsf{hypot}\left(1, 1 + x \cdot \left(0.5 + x \cdot 0.125\right)\right)\\
\end{array}
\end{array}
if x < -4.20000000000000018Initial program 100.0%
*-commutative100.0%
exp-lft-sqr100.0%
difference-of-sqr-1100.0%
associate-/l*100.0%
*-inverses100.0%
/-rgt-identity100.0%
+-commutative100.0%
Simplified100.0%
add-sqr-sqrt100.0%
hypot-1-def100.0%
Applied egg-rr100.0%
Taylor expanded in x around 0 5.9%
Taylor expanded in x around inf 1.2%
Taylor expanded in x around 0 97.4%
if -4.20000000000000018 < x Initial program 4.9%
*-commutative4.9%
exp-lft-sqr5.4%
difference-of-sqr-16.4%
associate-/l*6.4%
*-inverses100.0%
/-rgt-identity100.0%
+-commutative100.0%
Simplified100.0%
add-sqr-sqrt100.0%
hypot-1-def100.0%
Applied egg-rr100.0%
Taylor expanded in x around 0 98.2%
+-commutative98.2%
*-commutative98.2%
*-commutative98.2%
unpow298.2%
associate-*l*98.2%
distribute-lft-out98.2%
Simplified98.2%
Final simplification98.0%
(FPCore (x) :precision binary64 (if (<= x -4.3) (+ 1.0 (/ 1.0 x)) (hypot 1.0 (+ 1.0 (* x 0.5)))))
double code(double x) {
double tmp;
if (x <= -4.3) {
tmp = 1.0 + (1.0 / x);
} else {
tmp = hypot(1.0, (1.0 + (x * 0.5)));
}
return tmp;
}
public static double code(double x) {
double tmp;
if (x <= -4.3) {
tmp = 1.0 + (1.0 / x);
} else {
tmp = Math.hypot(1.0, (1.0 + (x * 0.5)));
}
return tmp;
}
def code(x): tmp = 0 if x <= -4.3: tmp = 1.0 + (1.0 / x) else: tmp = math.hypot(1.0, (1.0 + (x * 0.5))) return tmp
function code(x) tmp = 0.0 if (x <= -4.3) tmp = Float64(1.0 + Float64(1.0 / x)); else tmp = hypot(1.0, Float64(1.0 + Float64(x * 0.5))); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= -4.3) tmp = 1.0 + (1.0 / x); else tmp = hypot(1.0, (1.0 + (x * 0.5))); end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, -4.3], N[(1.0 + N[(1.0 / x), $MachinePrecision]), $MachinePrecision], N[Sqrt[1.0 ^ 2 + N[(1.0 + N[(x * 0.5), $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -4.3:\\
\;\;\;\;1 + \frac{1}{x}\\
\mathbf{else}:\\
\;\;\;\;\mathsf{hypot}\left(1, 1 + x \cdot 0.5\right)\\
\end{array}
\end{array}
if x < -4.29999999999999982Initial program 100.0%
*-commutative100.0%
exp-lft-sqr100.0%
difference-of-sqr-1100.0%
associate-/l*100.0%
*-inverses100.0%
/-rgt-identity100.0%
+-commutative100.0%
Simplified100.0%
add-sqr-sqrt100.0%
hypot-1-def100.0%
Applied egg-rr100.0%
Taylor expanded in x around 0 5.9%
Taylor expanded in x around inf 1.2%
Taylor expanded in x around 0 97.4%
if -4.29999999999999982 < x Initial program 4.9%
*-commutative4.9%
exp-lft-sqr5.4%
difference-of-sqr-16.4%
associate-/l*6.4%
*-inverses100.0%
/-rgt-identity100.0%
+-commutative100.0%
Simplified100.0%
add-sqr-sqrt100.0%
hypot-1-def100.0%
Applied egg-rr100.0%
Taylor expanded in x around 0 97.8%
Final simplification97.7%
(FPCore (x) :precision binary64 (if (<= x -4.6) (+ 1.0 (/ 1.0 x)) (pow (+ 0.5 (* x -0.25)) -0.5)))
double code(double x) {
double tmp;
if (x <= -4.6) {
tmp = 1.0 + (1.0 / x);
} else {
tmp = pow((0.5 + (x * -0.25)), -0.5);
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= (-4.6d0)) then
tmp = 1.0d0 + (1.0d0 / x)
else
tmp = (0.5d0 + (x * (-0.25d0))) ** (-0.5d0)
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= -4.6) {
tmp = 1.0 + (1.0 / x);
} else {
tmp = Math.pow((0.5 + (x * -0.25)), -0.5);
}
return tmp;
}
def code(x): tmp = 0 if x <= -4.6: tmp = 1.0 + (1.0 / x) else: tmp = math.pow((0.5 + (x * -0.25)), -0.5) return tmp
function code(x) tmp = 0.0 if (x <= -4.6) tmp = Float64(1.0 + Float64(1.0 / x)); else tmp = Float64(0.5 + Float64(x * -0.25)) ^ -0.5; end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= -4.6) tmp = 1.0 + (1.0 / x); else tmp = (0.5 + (x * -0.25)) ^ -0.5; end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, -4.6], N[(1.0 + N[(1.0 / x), $MachinePrecision]), $MachinePrecision], N[Power[N[(0.5 + N[(x * -0.25), $MachinePrecision]), $MachinePrecision], -0.5], $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -4.6:\\
\;\;\;\;1 + \frac{1}{x}\\
\mathbf{else}:\\
\;\;\;\;{\left(0.5 + x \cdot -0.25\right)}^{-0.5}\\
\end{array}
\end{array}
if x < -4.5999999999999996Initial program 100.0%
*-commutative100.0%
exp-lft-sqr100.0%
difference-of-sqr-1100.0%
associate-/l*100.0%
*-inverses100.0%
/-rgt-identity100.0%
+-commutative100.0%
Simplified100.0%
add-sqr-sqrt100.0%
hypot-1-def100.0%
Applied egg-rr100.0%
Taylor expanded in x around 0 5.9%
Taylor expanded in x around inf 1.2%
Taylor expanded in x around 0 97.4%
if -4.5999999999999996 < x Initial program 4.9%
*-commutative4.9%
exp-lft-sqr5.4%
difference-of-sqr-16.4%
associate-/l*6.4%
*-inverses100.0%
/-rgt-identity100.0%
+-commutative100.0%
Simplified100.0%
pow1/2100.0%
+-commutative100.0%
flip-+5.4%
metadata-eval5.4%
exp-lft-sqr4.9%
*-commutative4.9%
expm1-udef7.4%
expm1-udef99.4%
div-inv98.7%
div-inv99.4%
clear-num99.4%
inv-pow99.4%
metadata-eval99.4%
pow-pow99.4%
Applied egg-rr100.0%
Taylor expanded in x around 0 98.1%
*-commutative98.1%
Simplified98.1%
Final simplification97.9%
(FPCore (x) :precision binary64 (if (<= x -1.8) (+ 1.0 (/ 1.0 x)) (sqrt (+ x 2.0))))
double code(double x) {
double tmp;
if (x <= -1.8) {
tmp = 1.0 + (1.0 / x);
} else {
tmp = sqrt((x + 2.0));
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= (-1.8d0)) then
tmp = 1.0d0 + (1.0d0 / x)
else
tmp = sqrt((x + 2.0d0))
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= -1.8) {
tmp = 1.0 + (1.0 / x);
} else {
tmp = Math.sqrt((x + 2.0));
}
return tmp;
}
def code(x): tmp = 0 if x <= -1.8: tmp = 1.0 + (1.0 / x) else: tmp = math.sqrt((x + 2.0)) return tmp
function code(x) tmp = 0.0 if (x <= -1.8) tmp = Float64(1.0 + Float64(1.0 / x)); else tmp = sqrt(Float64(x + 2.0)); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= -1.8) tmp = 1.0 + (1.0 / x); else tmp = sqrt((x + 2.0)); end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, -1.8], N[(1.0 + N[(1.0 / x), $MachinePrecision]), $MachinePrecision], N[Sqrt[N[(x + 2.0), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.8:\\
\;\;\;\;1 + \frac{1}{x}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{x + 2}\\
\end{array}
\end{array}
if x < -1.80000000000000004Initial program 100.0%
*-commutative100.0%
exp-lft-sqr100.0%
difference-of-sqr-1100.0%
associate-/l*100.0%
*-inverses100.0%
/-rgt-identity100.0%
+-commutative100.0%
Simplified100.0%
add-sqr-sqrt100.0%
hypot-1-def100.0%
Applied egg-rr100.0%
Taylor expanded in x around 0 5.9%
Taylor expanded in x around inf 1.2%
Taylor expanded in x around 0 97.4%
if -1.80000000000000004 < x Initial program 4.9%
*-commutative4.9%
exp-lft-sqr5.4%
difference-of-sqr-16.4%
associate-/l*6.4%
*-inverses100.0%
/-rgt-identity100.0%
+-commutative100.0%
Simplified100.0%
Taylor expanded in x around 0 97.7%
Final simplification97.6%
(FPCore (x) :precision binary64 (if (<= x -4.9) (+ 1.0 (/ 1.0 x)) (sqrt 2.0)))
double code(double x) {
double tmp;
if (x <= -4.9) {
tmp = 1.0 + (1.0 / x);
} else {
tmp = sqrt(2.0);
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= (-4.9d0)) then
tmp = 1.0d0 + (1.0d0 / x)
else
tmp = sqrt(2.0d0)
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= -4.9) {
tmp = 1.0 + (1.0 / x);
} else {
tmp = Math.sqrt(2.0);
}
return tmp;
}
def code(x): tmp = 0 if x <= -4.9: tmp = 1.0 + (1.0 / x) else: tmp = math.sqrt(2.0) return tmp
function code(x) tmp = 0.0 if (x <= -4.9) tmp = Float64(1.0 + Float64(1.0 / x)); else tmp = sqrt(2.0); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= -4.9) tmp = 1.0 + (1.0 / x); else tmp = sqrt(2.0); end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, -4.9], N[(1.0 + N[(1.0 / x), $MachinePrecision]), $MachinePrecision], N[Sqrt[2.0], $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -4.9:\\
\;\;\;\;1 + \frac{1}{x}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{2}\\
\end{array}
\end{array}
if x < -4.9000000000000004Initial program 100.0%
*-commutative100.0%
exp-lft-sqr100.0%
difference-of-sqr-1100.0%
associate-/l*100.0%
*-inverses100.0%
/-rgt-identity100.0%
+-commutative100.0%
Simplified100.0%
add-sqr-sqrt100.0%
hypot-1-def100.0%
Applied egg-rr100.0%
Taylor expanded in x around 0 5.9%
Taylor expanded in x around inf 1.2%
Taylor expanded in x around 0 97.4%
if -4.9000000000000004 < x Initial program 4.9%
*-commutative4.9%
exp-lft-sqr5.4%
difference-of-sqr-16.4%
associate-/l*6.4%
*-inverses100.0%
/-rgt-identity100.0%
+-commutative100.0%
Simplified100.0%
Taylor expanded in x around 0 96.6%
Final simplification96.8%
(FPCore (x) :precision binary64 (if (<= x -1.42) (+ 1.0 (/ 1.0 x)) (+ 1.0 (* x 0.5))))
double code(double x) {
double tmp;
if (x <= -1.42) {
tmp = 1.0 + (1.0 / x);
} else {
tmp = 1.0 + (x * 0.5);
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= (-1.42d0)) then
tmp = 1.0d0 + (1.0d0 / x)
else
tmp = 1.0d0 + (x * 0.5d0)
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= -1.42) {
tmp = 1.0 + (1.0 / x);
} else {
tmp = 1.0 + (x * 0.5);
}
return tmp;
}
def code(x): tmp = 0 if x <= -1.42: tmp = 1.0 + (1.0 / x) else: tmp = 1.0 + (x * 0.5) return tmp
function code(x) tmp = 0.0 if (x <= -1.42) tmp = Float64(1.0 + Float64(1.0 / x)); else tmp = Float64(1.0 + Float64(x * 0.5)); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= -1.42) tmp = 1.0 + (1.0 / x); else tmp = 1.0 + (x * 0.5); end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, -1.42], N[(1.0 + N[(1.0 / x), $MachinePrecision]), $MachinePrecision], N[(1.0 + N[(x * 0.5), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.42:\\
\;\;\;\;1 + \frac{1}{x}\\
\mathbf{else}:\\
\;\;\;\;1 + x \cdot 0.5\\
\end{array}
\end{array}
if x < -1.4199999999999999Initial program 100.0%
*-commutative100.0%
exp-lft-sqr100.0%
difference-of-sqr-1100.0%
associate-/l*100.0%
*-inverses100.0%
/-rgt-identity100.0%
+-commutative100.0%
Simplified100.0%
add-sqr-sqrt100.0%
hypot-1-def100.0%
Applied egg-rr100.0%
Taylor expanded in x around 0 5.9%
Taylor expanded in x around inf 1.2%
Taylor expanded in x around 0 97.4%
if -1.4199999999999999 < x Initial program 4.9%
*-commutative4.9%
exp-lft-sqr5.4%
difference-of-sqr-16.4%
associate-/l*6.4%
*-inverses100.0%
/-rgt-identity100.0%
+-commutative100.0%
Simplified100.0%
add-sqr-sqrt100.0%
hypot-1-def100.0%
Applied egg-rr100.0%
Taylor expanded in x around 0 97.8%
Taylor expanded in x around inf 20.6%
Final simplification41.0%
(FPCore (x) :precision binary64 (+ 1.0 (* x 0.5)))
double code(double x) {
return 1.0 + (x * 0.5);
}
real(8) function code(x)
real(8), intent (in) :: x
code = 1.0d0 + (x * 0.5d0)
end function
public static double code(double x) {
return 1.0 + (x * 0.5);
}
def code(x): return 1.0 + (x * 0.5)
function code(x) return Float64(1.0 + Float64(x * 0.5)) end
function tmp = code(x) tmp = 1.0 + (x * 0.5); end
code[x_] := N[(1.0 + N[(x * 0.5), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
1 + x \cdot 0.5
\end{array}
Initial program 30.2%
*-commutative30.2%
exp-lft-sqr30.5%
difference-of-sqr-131.2%
associate-/l*31.2%
*-inverses100.0%
/-rgt-identity100.0%
+-commutative100.0%
Simplified100.0%
add-sqr-sqrt100.0%
hypot-1-def100.0%
Applied egg-rr100.0%
Taylor expanded in x around 0 73.4%
Taylor expanded in x around inf 15.5%
Final simplification15.5%
(FPCore (x) :precision binary64 (* x 0.5))
double code(double x) {
return x * 0.5;
}
real(8) function code(x)
real(8), intent (in) :: x
code = x * 0.5d0
end function
public static double code(double x) {
return x * 0.5;
}
def code(x): return x * 0.5
function code(x) return Float64(x * 0.5) end
function tmp = code(x) tmp = x * 0.5; end
code[x_] := N[(x * 0.5), $MachinePrecision]
\begin{array}{l}
\\
x \cdot 0.5
\end{array}
Initial program 30.2%
*-commutative30.2%
exp-lft-sqr30.5%
difference-of-sqr-131.2%
associate-/l*31.2%
*-inverses100.0%
/-rgt-identity100.0%
+-commutative100.0%
Simplified100.0%
add-sqr-sqrt100.0%
hypot-1-def100.0%
Applied egg-rr100.0%
Taylor expanded in x around 0 73.4%
Taylor expanded in x around inf 3.2%
Final simplification3.2%
(FPCore (x) :precision binary64 (* x -0.5))
double code(double x) {
return x * -0.5;
}
real(8) function code(x)
real(8), intent (in) :: x
code = x * (-0.5d0)
end function
public static double code(double x) {
return x * -0.5;
}
def code(x): return x * -0.5
function code(x) return Float64(x * -0.5) end
function tmp = code(x) tmp = x * -0.5; end
code[x_] := N[(x * -0.5), $MachinePrecision]
\begin{array}{l}
\\
x \cdot -0.5
\end{array}
Initial program 30.2%
*-commutative30.2%
exp-lft-sqr30.5%
difference-of-sqr-131.2%
associate-/l*31.2%
*-inverses100.0%
/-rgt-identity100.0%
+-commutative100.0%
Simplified100.0%
add-sqr-sqrt100.0%
hypot-1-def100.0%
Applied egg-rr100.0%
Taylor expanded in x around 0 73.4%
Taylor expanded in x around -inf 4.4%
*-commutative4.4%
Simplified4.4%
Final simplification4.4%
herbie shell --seed 2024019
(FPCore (x)
:name "sqrtexp (problem 3.4.4)"
:precision binary64
(sqrt (/ (- (exp (* 2.0 x)) 1.0) (- (exp x) 1.0))))