
(FPCore (a b c) :precision binary64 (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))
double code(double a, double b, double c) {
return (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = (-b + sqrt(((b * b) - ((4.0d0 * a) * c)))) / (2.0d0 * a)
end function
public static double code(double a, double b, double c) {
return (-b + Math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
}
def code(a, b, c): return (-b + math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a)
function code(a, b, c) return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(4.0 * a) * c)))) / Float64(2.0 * a)) end
function tmp = code(a, b, c) tmp = (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a); end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(4.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (a b c) :precision binary64 (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))
double code(double a, double b, double c) {
return (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = (-b + sqrt(((b * b) - ((4.0d0 * a) * c)))) / (2.0d0 * a)
end function
public static double code(double a, double b, double c) {
return (-b + Math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
}
def code(a, b, c): return (-b + math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a)
function code(a, b, c) return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(4.0 * a) * c)))) / Float64(2.0 * a)) end
function tmp = code(a, b, c) tmp = (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a); end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(4.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a}
\end{array}
(FPCore (a b c)
:precision binary64
(if (<= b -2e+128)
(- (/ c b) (/ b a))
(if (<= b 4e-96)
(/ (- (sqrt (- (* b b) (* c (* a 4.0)))) b) (* a 2.0))
(/ (- c) b))))
double code(double a, double b, double c) {
double tmp;
if (b <= -2e+128) {
tmp = (c / b) - (b / a);
} else if (b <= 4e-96) {
tmp = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
} else {
tmp = -c / b;
}
return tmp;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
real(8) :: tmp
if (b <= (-2d+128)) then
tmp = (c / b) - (b / a)
else if (b <= 4d-96) then
tmp = (sqrt(((b * b) - (c * (a * 4.0d0)))) - b) / (a * 2.0d0)
else
tmp = -c / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -2e+128) {
tmp = (c / b) - (b / a);
} else if (b <= 4e-96) {
tmp = (Math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -2e+128: tmp = (c / b) - (b / a) elif b <= 4e-96: tmp = (math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0) else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -2e+128) tmp = Float64(Float64(c / b) - Float64(b / a)); elseif (b <= 4e-96) tmp = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0)))) - b) / Float64(a * 2.0)); else tmp = Float64(Float64(-c) / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -2e+128) tmp = (c / b) - (b / a); elseif (b <= 4e-96) tmp = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0); else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -2e+128], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], If[LessEqual[b, 4e-96], N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -2 \cdot 10^{+128}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{elif}\;b \leq 4 \cdot 10^{-96}:\\
\;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
if b < -2.0000000000000002e128Initial program 42.2%
*-commutative42.2%
Simplified42.2%
Taylor expanded in b around -inf 95.0%
+-commutative95.0%
mul-1-neg95.0%
unsub-neg95.0%
Simplified95.0%
if -2.0000000000000002e128 < b < 3.9999999999999996e-96Initial program 82.2%
if 3.9999999999999996e-96 < b Initial program 14.7%
*-commutative14.7%
Simplified14.7%
Taylor expanded in b around inf 89.8%
mul-1-neg89.8%
distribute-neg-frac89.8%
Simplified89.8%
Final simplification87.1%
(FPCore (a b c)
:precision binary64
(if (<= b -3.7e-84)
(/ (- b) a)
(if (<= b 1.35e-97)
(/ (- (sqrt (* c (* a -4.0))) b) (* a 2.0))
(/ (- c) b))))
double code(double a, double b, double c) {
double tmp;
if (b <= -3.7e-84) {
tmp = -b / a;
} else if (b <= 1.35e-97) {
tmp = (sqrt((c * (a * -4.0))) - b) / (a * 2.0);
} else {
tmp = -c / b;
}
return tmp;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
real(8) :: tmp
if (b <= (-3.7d-84)) then
tmp = -b / a
else if (b <= 1.35d-97) then
tmp = (sqrt((c * (a * (-4.0d0)))) - b) / (a * 2.0d0)
else
tmp = -c / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -3.7e-84) {
tmp = -b / a;
} else if (b <= 1.35e-97) {
tmp = (Math.sqrt((c * (a * -4.0))) - b) / (a * 2.0);
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -3.7e-84: tmp = -b / a elif b <= 1.35e-97: tmp = (math.sqrt((c * (a * -4.0))) - b) / (a * 2.0) else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -3.7e-84) tmp = Float64(Float64(-b) / a); elseif (b <= 1.35e-97) tmp = Float64(Float64(sqrt(Float64(c * Float64(a * -4.0))) - b) / Float64(a * 2.0)); else tmp = Float64(Float64(-c) / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -3.7e-84) tmp = -b / a; elseif (b <= 1.35e-97) tmp = (sqrt((c * (a * -4.0))) - b) / (a * 2.0); else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -3.7e-84], N[((-b) / a), $MachinePrecision], If[LessEqual[b, 1.35e-97], N[(N[(N[Sqrt[N[(c * N[(a * -4.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -3.7 \cdot 10^{-84}:\\
\;\;\;\;\frac{-b}{a}\\
\mathbf{elif}\;b \leq 1.35 \cdot 10^{-97}:\\
\;\;\;\;\frac{\sqrt{c \cdot \left(a \cdot -4\right)} - b}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
if b < -3.6999999999999999e-84Initial program 68.1%
*-commutative68.1%
Simplified68.1%
Taylor expanded in b around -inf 87.2%
associate-*r/87.2%
mul-1-neg87.2%
Simplified87.2%
if -3.6999999999999999e-84 < b < 1.34999999999999993e-97Initial program 77.1%
*-commutative77.1%
Simplified77.1%
prod-diff76.8%
*-commutative76.8%
fma-def76.8%
associate-+l+76.8%
pow276.8%
distribute-lft-neg-in76.8%
*-commutative76.8%
distribute-rgt-neg-in76.8%
metadata-eval76.8%
associate-*r*76.8%
*-commutative76.8%
*-commutative76.8%
fma-udef76.8%
Applied egg-rr76.8%
fma-def76.8%
fma-def76.8%
associate-*l*76.8%
Simplified76.8%
Taylor expanded in b around 0 75.3%
neg-mul-175.3%
unsub-neg75.3%
associate-*r*75.3%
associate-*r*75.4%
distribute-rgt-in75.6%
distribute-rgt-out75.6%
metadata-eval75.6%
Simplified75.6%
if 1.34999999999999993e-97 < b Initial program 14.7%
*-commutative14.7%
Simplified14.7%
Taylor expanded in b around inf 89.8%
mul-1-neg89.8%
distribute-neg-frac89.8%
Simplified89.8%
Final simplification84.9%
(FPCore (a b c) :precision binary64 (if (<= b -3.2e-84) (/ (- b) a) (if (<= b 2.95e-95) (* 0.5 (/ (sqrt (* c (* a -4.0))) a)) (/ (- c) b))))
double code(double a, double b, double c) {
double tmp;
if (b <= -3.2e-84) {
tmp = -b / a;
} else if (b <= 2.95e-95) {
tmp = 0.5 * (sqrt((c * (a * -4.0))) / a);
} else {
tmp = -c / b;
}
return tmp;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
real(8) :: tmp
if (b <= (-3.2d-84)) then
tmp = -b / a
else if (b <= 2.95d-95) then
tmp = 0.5d0 * (sqrt((c * (a * (-4.0d0)))) / a)
else
tmp = -c / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -3.2e-84) {
tmp = -b / a;
} else if (b <= 2.95e-95) {
tmp = 0.5 * (Math.sqrt((c * (a * -4.0))) / a);
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -3.2e-84: tmp = -b / a elif b <= 2.95e-95: tmp = 0.5 * (math.sqrt((c * (a * -4.0))) / a) else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -3.2e-84) tmp = Float64(Float64(-b) / a); elseif (b <= 2.95e-95) tmp = Float64(0.5 * Float64(sqrt(Float64(c * Float64(a * -4.0))) / a)); else tmp = Float64(Float64(-c) / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -3.2e-84) tmp = -b / a; elseif (b <= 2.95e-95) tmp = 0.5 * (sqrt((c * (a * -4.0))) / a); else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -3.2e-84], N[((-b) / a), $MachinePrecision], If[LessEqual[b, 2.95e-95], N[(0.5 * N[(N[Sqrt[N[(c * N[(a * -4.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -3.2 \cdot 10^{-84}:\\
\;\;\;\;\frac{-b}{a}\\
\mathbf{elif}\;b \leq 2.95 \cdot 10^{-95}:\\
\;\;\;\;0.5 \cdot \frac{\sqrt{c \cdot \left(a \cdot -4\right)}}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
if b < -3.1999999999999999e-84Initial program 68.1%
*-commutative68.1%
Simplified68.1%
Taylor expanded in b around -inf 87.2%
associate-*r/87.2%
mul-1-neg87.2%
Simplified87.2%
if -3.1999999999999999e-84 < b < 2.9499999999999999e-95Initial program 77.1%
*-commutative77.1%
Simplified77.1%
prod-diff76.8%
*-commutative76.8%
fma-def76.8%
associate-+l+76.8%
pow276.8%
distribute-lft-neg-in76.8%
*-commutative76.8%
distribute-rgt-neg-in76.8%
metadata-eval76.8%
associate-*r*76.8%
*-commutative76.8%
*-commutative76.8%
fma-udef76.8%
Applied egg-rr76.8%
fma-def76.8%
fma-def76.8%
associate-*l*76.8%
Simplified76.8%
Taylor expanded in b around 0 73.4%
associate-*l/73.5%
*-lft-identity73.5%
associate-*r*73.5%
associate-*r*73.5%
distribute-rgt-in73.8%
distribute-rgt-out73.8%
metadata-eval73.8%
Simplified73.8%
if 2.9499999999999999e-95 < b Initial program 14.7%
*-commutative14.7%
Simplified14.7%
Taylor expanded in b around inf 89.8%
mul-1-neg89.8%
distribute-neg-frac89.8%
Simplified89.8%
Final simplification84.3%
(FPCore (a b c) :precision binary64 (if (<= b -5e-310) (- (/ c b) (/ b a)) (/ (- c) b)))
double code(double a, double b, double c) {
double tmp;
if (b <= -5e-310) {
tmp = (c / b) - (b / a);
} else {
tmp = -c / b;
}
return tmp;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
real(8) :: tmp
if (b <= (-5d-310)) then
tmp = (c / b) - (b / a)
else
tmp = -c / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -5e-310) {
tmp = (c / b) - (b / a);
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -5e-310: tmp = (c / b) - (b / a) else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -5e-310) tmp = Float64(Float64(c / b) - Float64(b / a)); else tmp = Float64(Float64(-c) / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -5e-310) tmp = (c / b) - (b / a); else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -5e-310], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision], N[((-c) / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -5 \cdot 10^{-310}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
if b < -4.999999999999985e-310Initial program 72.9%
*-commutative72.9%
Simplified72.9%
Taylor expanded in b around -inf 63.3%
+-commutative63.3%
mul-1-neg63.3%
unsub-neg63.3%
Simplified63.3%
if -4.999999999999985e-310 < b Initial program 27.8%
*-commutative27.8%
Simplified27.8%
Taylor expanded in b around inf 71.2%
mul-1-neg71.2%
distribute-neg-frac71.2%
Simplified71.2%
Final simplification67.4%
(FPCore (a b c) :precision binary64 (if (<= b 3.2e-49) (/ (- b) a) (/ c b)))
double code(double a, double b, double c) {
double tmp;
if (b <= 3.2e-49) {
tmp = -b / a;
} else {
tmp = c / b;
}
return tmp;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
real(8) :: tmp
if (b <= 3.2d-49) then
tmp = -b / a
else
tmp = c / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= 3.2e-49) {
tmp = -b / a;
} else {
tmp = c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= 3.2e-49: tmp = -b / a else: tmp = c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= 3.2e-49) tmp = Float64(Float64(-b) / a); else tmp = Float64(c / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= 3.2e-49) tmp = -b / a; else tmp = c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, 3.2e-49], N[((-b) / a), $MachinePrecision], N[(c / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 3.2 \cdot 10^{-49}:\\
\;\;\;\;\frac{-b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{b}\\
\end{array}
\end{array}
if b < 3.20000000000000002e-49Initial program 70.8%
*-commutative70.8%
Simplified70.8%
Taylor expanded in b around -inf 48.7%
associate-*r/48.7%
mul-1-neg48.7%
Simplified48.7%
if 3.20000000000000002e-49 < b Initial program 12.5%
*-commutative12.5%
Simplified12.5%
Taylor expanded in b around -inf 2.5%
Taylor expanded in b around 0 21.8%
Final simplification38.9%
(FPCore (a b c) :precision binary64 (if (<= b -5e-310) (/ (- b) a) (/ (- c) b)))
double code(double a, double b, double c) {
double tmp;
if (b <= -5e-310) {
tmp = -b / a;
} else {
tmp = -c / b;
}
return tmp;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
real(8) :: tmp
if (b <= (-5d-310)) then
tmp = -b / a
else
tmp = -c / b
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -5e-310) {
tmp = -b / a;
} else {
tmp = -c / b;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -5e-310: tmp = -b / a else: tmp = -c / b return tmp
function code(a, b, c) tmp = 0.0 if (b <= -5e-310) tmp = Float64(Float64(-b) / a); else tmp = Float64(Float64(-c) / b); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -5e-310) tmp = -b / a; else tmp = -c / b; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -5e-310], N[((-b) / a), $MachinePrecision], N[((-c) / b), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -5 \cdot 10^{-310}:\\
\;\;\;\;\frac{-b}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\
\end{array}
\end{array}
if b < -4.999999999999985e-310Initial program 72.9%
*-commutative72.9%
Simplified72.9%
Taylor expanded in b around -inf 63.0%
associate-*r/63.0%
mul-1-neg63.0%
Simplified63.0%
if -4.999999999999985e-310 < b Initial program 27.8%
*-commutative27.8%
Simplified27.8%
Taylor expanded in b around inf 71.2%
mul-1-neg71.2%
distribute-neg-frac71.2%
Simplified71.2%
Final simplification67.3%
(FPCore (a b c) :precision binary64 (/ b a))
double code(double a, double b, double c) {
return b / a;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = b / a
end function
public static double code(double a, double b, double c) {
return b / a;
}
def code(a, b, c): return b / a
function code(a, b, c) return Float64(b / a) end
function tmp = code(a, b, c) tmp = b / a; end
code[a_, b_, c_] := N[(b / a), $MachinePrecision]
\begin{array}{l}
\\
\frac{b}{a}
\end{array}
Initial program 49.6%
*-commutative49.6%
Simplified49.6%
Applied egg-rr31.3%
Taylor expanded in b around inf 2.3%
+-commutative2.3%
mul-1-neg2.3%
unsub-neg2.3%
Simplified2.3%
Taylor expanded in c around 0 2.5%
pow-base-12.5%
*-lft-identity2.5%
Simplified2.5%
Final simplification2.5%
(FPCore (a b c) :precision binary64 (/ c b))
double code(double a, double b, double c) {
return c / b;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = c / b
end function
public static double code(double a, double b, double c) {
return c / b;
}
def code(a, b, c): return c / b
function code(a, b, c) return Float64(c / b) end
function tmp = code(a, b, c) tmp = c / b; end
code[a_, b_, c_] := N[(c / b), $MachinePrecision]
\begin{array}{l}
\\
\frac{c}{b}
\end{array}
Initial program 49.6%
*-commutative49.6%
Simplified49.6%
Taylor expanded in b around -inf 30.9%
Taylor expanded in b around 0 9.9%
Final simplification9.9%
herbie shell --seed 2024014
(FPCore (a b c)
:name "Quadratic roots, full range"
:precision binary64
(/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))