| Alternative 1 | |
|---|---|
| Error | 5.5 |
| Cost | 12680 |
(FPCore (x y z t a b c i j) :precision binary64 (+ (- (* x (- (* y z) (* t a))) (* b (- (* c z) (* i a)))) (* j (- (* c t) (* i y)))))
(FPCore (x y z t a b c i j)
:precision binary64
(let* ((t_1 (* x (- (* y z) (* t a))))
(t_2 (* b (- (* a i) (* z c))))
(t_3 (* j (- (* t c) (* y i))))
(t_4 (+ (+ t_2 t_1) t_3)))
(if (<= t_4 (- INFINITY))
(- (+ (* c (* t j)) (* y (- (* x z) (* i j)))) (* c (* z b)))
(if (<= t_4 1e+308)
(+ (- t_1 (- (* b (fma (- a) i (* a i))) t_2)) t_3)
(fma c (fma (- b) z (* t j)) (* i (fma a b (* j (- y)))))))))double code(double x, double y, double z, double t, double a, double b, double c, double i, double j) {
return ((x * ((y * z) - (t * a))) - (b * ((c * z) - (i * a)))) + (j * ((c * t) - (i * y)));
}
double code(double x, double y, double z, double t, double a, double b, double c, double i, double j) {
double t_1 = x * ((y * z) - (t * a));
double t_2 = b * ((a * i) - (z * c));
double t_3 = j * ((t * c) - (y * i));
double t_4 = (t_2 + t_1) + t_3;
double tmp;
if (t_4 <= -((double) INFINITY)) {
tmp = ((c * (t * j)) + (y * ((x * z) - (i * j)))) - (c * (z * b));
} else if (t_4 <= 1e+308) {
tmp = (t_1 - ((b * fma(-a, i, (a * i))) - t_2)) + t_3;
} else {
tmp = fma(c, fma(-b, z, (t * j)), (i * fma(a, b, (j * -y))));
}
return tmp;
}
function code(x, y, z, t, a, b, c, i, j) return Float64(Float64(Float64(x * Float64(Float64(y * z) - Float64(t * a))) - Float64(b * Float64(Float64(c * z) - Float64(i * a)))) + Float64(j * Float64(Float64(c * t) - Float64(i * y)))) end
function code(x, y, z, t, a, b, c, i, j) t_1 = Float64(x * Float64(Float64(y * z) - Float64(t * a))) t_2 = Float64(b * Float64(Float64(a * i) - Float64(z * c))) t_3 = Float64(j * Float64(Float64(t * c) - Float64(y * i))) t_4 = Float64(Float64(t_2 + t_1) + t_3) tmp = 0.0 if (t_4 <= Float64(-Inf)) tmp = Float64(Float64(Float64(c * Float64(t * j)) + Float64(y * Float64(Float64(x * z) - Float64(i * j)))) - Float64(c * Float64(z * b))); elseif (t_4 <= 1e+308) tmp = Float64(Float64(t_1 - Float64(Float64(b * fma(Float64(-a), i, Float64(a * i))) - t_2)) + t_3); else tmp = fma(c, fma(Float64(-b), z, Float64(t * j)), Float64(i * fma(a, b, Float64(j * Float64(-y))))); end return tmp end
code[x_, y_, z_, t_, a_, b_, c_, i_, j_] := N[(N[(N[(x * N[(N[(y * z), $MachinePrecision] - N[(t * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(b * N[(N[(c * z), $MachinePrecision] - N[(i * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(j * N[(N[(c * t), $MachinePrecision] - N[(i * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
code[x_, y_, z_, t_, a_, b_, c_, i_, j_] := Block[{t$95$1 = N[(x * N[(N[(y * z), $MachinePrecision] - N[(t * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(b * N[(N[(a * i), $MachinePrecision] - N[(z * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(j * N[(N[(t * c), $MachinePrecision] - N[(y * i), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$4 = N[(N[(t$95$2 + t$95$1), $MachinePrecision] + t$95$3), $MachinePrecision]}, If[LessEqual[t$95$4, (-Infinity)], N[(N[(N[(c * N[(t * j), $MachinePrecision]), $MachinePrecision] + N[(y * N[(N[(x * z), $MachinePrecision] - N[(i * j), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(c * N[(z * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$4, 1e+308], N[(N[(t$95$1 - N[(N[(b * N[((-a) * i + N[(a * i), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - t$95$2), $MachinePrecision]), $MachinePrecision] + t$95$3), $MachinePrecision], N[(c * N[((-b) * z + N[(t * j), $MachinePrecision]), $MachinePrecision] + N[(i * N[(a * b + N[(j * (-y)), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]]]]
\left(x \cdot \left(y \cdot z - t \cdot a\right) - b \cdot \left(c \cdot z - i \cdot a\right)\right) + j \cdot \left(c \cdot t - i \cdot y\right)
\begin{array}{l}
t_1 := x \cdot \left(y \cdot z - t \cdot a\right)\\
t_2 := b \cdot \left(a \cdot i - z \cdot c\right)\\
t_3 := j \cdot \left(t \cdot c - y \cdot i\right)\\
t_4 := \left(t_2 + t_1\right) + t_3\\
\mathbf{if}\;t_4 \leq -\infty:\\
\;\;\;\;\left(c \cdot \left(t \cdot j\right) + y \cdot \left(x \cdot z - i \cdot j\right)\right) - c \cdot \left(z \cdot b\right)\\
\mathbf{elif}\;t_4 \leq 10^{+308}:\\
\;\;\;\;\left(t_1 - \left(b \cdot \mathsf{fma}\left(-a, i, a \cdot i\right) - t_2\right)\right) + t_3\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(c, \mathsf{fma}\left(-b, z, t \cdot j\right), i \cdot \mathsf{fma}\left(a, b, j \cdot \left(-y\right)\right)\right)\\
\end{array}
| Original | 12.0 |
|---|---|
| Target | 15.8 |
| Herbie | 5.3 |
if (+.f64 (-.f64 (*.f64 x (-.f64 (*.f64 y z) (*.f64 t a))) (*.f64 b (-.f64 (*.f64 c z) (*.f64 i a)))) (*.f64 j (-.f64 (*.f64 c t) (*.f64 i y)))) < -inf.0Initial program 64.0
Simplified64.0
[Start]64.0 | \[ \left(x \cdot \left(y \cdot z - t \cdot a\right) - b \cdot \left(c \cdot z - i \cdot a\right)\right) + j \cdot \left(c \cdot t - i \cdot y\right)
\] |
|---|---|
associate-+l- [=>]64.0 | \[ \color{blue}{x \cdot \left(y \cdot z - t \cdot a\right) - \left(b \cdot \left(c \cdot z - i \cdot a\right) - j \cdot \left(c \cdot t - i \cdot y\right)\right)}
\] |
fma-neg [=>]64.0 | \[ \color{blue}{\mathsf{fma}\left(x, y \cdot z - t \cdot a, -\left(b \cdot \left(c \cdot z - i \cdot a\right) - j \cdot \left(c \cdot t - i \cdot y\right)\right)\right)}
\] |
neg-sub0 [=>]64.0 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \color{blue}{0 - \left(b \cdot \left(c \cdot z - i \cdot a\right) - j \cdot \left(c \cdot t - i \cdot y\right)\right)}\right)
\] |
associate-+l- [<=]64.0 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \color{blue}{\left(0 - b \cdot \left(c \cdot z - i \cdot a\right)\right) + j \cdot \left(c \cdot t - i \cdot y\right)}\right)
\] |
neg-sub0 [<=]64.0 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \color{blue}{\left(-b \cdot \left(c \cdot z - i \cdot a\right)\right)} + j \cdot \left(c \cdot t - i \cdot y\right)\right)
\] |
distribute-rgt-neg-in [=>]64.0 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \color{blue}{b \cdot \left(-\left(c \cdot z - i \cdot a\right)\right)} + j \cdot \left(c \cdot t - i \cdot y\right)\right)
\] |
fma-def [=>]64.0 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \color{blue}{\mathsf{fma}\left(b, -\left(c \cdot z - i \cdot a\right), j \cdot \left(c \cdot t - i \cdot y\right)\right)}\right)
\] |
sub-neg [=>]64.0 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \mathsf{fma}\left(b, -\color{blue}{\left(c \cdot z + \left(-i \cdot a\right)\right)}, j \cdot \left(c \cdot t - i \cdot y\right)\right)\right)
\] |
distribute-neg-in [=>]64.0 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \mathsf{fma}\left(b, \color{blue}{\left(-c \cdot z\right) + \left(-\left(-i \cdot a\right)\right)}, j \cdot \left(c \cdot t - i \cdot y\right)\right)\right)
\] |
+-commutative [=>]64.0 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \mathsf{fma}\left(b, \color{blue}{\left(-\left(-i \cdot a\right)\right) + \left(-c \cdot z\right)}, j \cdot \left(c \cdot t - i \cdot y\right)\right)\right)
\] |
remove-double-neg [=>]64.0 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \mathsf{fma}\left(b, \color{blue}{i \cdot a} + \left(-c \cdot z\right), j \cdot \left(c \cdot t - i \cdot y\right)\right)\right)
\] |
sub-neg [<=]64.0 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \mathsf{fma}\left(b, \color{blue}{i \cdot a - c \cdot z}, j \cdot \left(c \cdot t - i \cdot y\right)\right)\right)
\] |
*-commutative [=>]64.0 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \mathsf{fma}\left(b, \color{blue}{a \cdot i} - c \cdot z, j \cdot \left(c \cdot t - i \cdot y\right)\right)\right)
\] |
*-commutative [=>]64.0 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \mathsf{fma}\left(b, a \cdot i - \color{blue}{z \cdot c}, j \cdot \left(c \cdot t - i \cdot y\right)\right)\right)
\] |
Taylor expanded in a around 0 43.3
Taylor expanded in y around 0 27.2
if -inf.0 < (+.f64 (-.f64 (*.f64 x (-.f64 (*.f64 y z) (*.f64 t a))) (*.f64 b (-.f64 (*.f64 c z) (*.f64 i a)))) (*.f64 j (-.f64 (*.f64 c t) (*.f64 i y)))) < 1e308Initial program 0.8
Applied egg-rr0.8
if 1e308 < (+.f64 (-.f64 (*.f64 x (-.f64 (*.f64 y z) (*.f64 t a))) (*.f64 b (-.f64 (*.f64 c z) (*.f64 i a)))) (*.f64 j (-.f64 (*.f64 c t) (*.f64 i y)))) Initial program 63.8
Simplified63.8
[Start]63.8 | \[ \left(x \cdot \left(y \cdot z - t \cdot a\right) - b \cdot \left(c \cdot z - i \cdot a\right)\right) + j \cdot \left(c \cdot t - i \cdot y\right)
\] |
|---|---|
associate-+l- [=>]63.8 | \[ \color{blue}{x \cdot \left(y \cdot z - t \cdot a\right) - \left(b \cdot \left(c \cdot z - i \cdot a\right) - j \cdot \left(c \cdot t - i \cdot y\right)\right)}
\] |
fma-neg [=>]63.8 | \[ \color{blue}{\mathsf{fma}\left(x, y \cdot z - t \cdot a, -\left(b \cdot \left(c \cdot z - i \cdot a\right) - j \cdot \left(c \cdot t - i \cdot y\right)\right)\right)}
\] |
neg-sub0 [=>]63.8 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \color{blue}{0 - \left(b \cdot \left(c \cdot z - i \cdot a\right) - j \cdot \left(c \cdot t - i \cdot y\right)\right)}\right)
\] |
associate-+l- [<=]63.8 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \color{blue}{\left(0 - b \cdot \left(c \cdot z - i \cdot a\right)\right) + j \cdot \left(c \cdot t - i \cdot y\right)}\right)
\] |
neg-sub0 [<=]63.8 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \color{blue}{\left(-b \cdot \left(c \cdot z - i \cdot a\right)\right)} + j \cdot \left(c \cdot t - i \cdot y\right)\right)
\] |
distribute-rgt-neg-in [=>]63.8 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \color{blue}{b \cdot \left(-\left(c \cdot z - i \cdot a\right)\right)} + j \cdot \left(c \cdot t - i \cdot y\right)\right)
\] |
fma-def [=>]63.8 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \color{blue}{\mathsf{fma}\left(b, -\left(c \cdot z - i \cdot a\right), j \cdot \left(c \cdot t - i \cdot y\right)\right)}\right)
\] |
sub-neg [=>]63.8 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \mathsf{fma}\left(b, -\color{blue}{\left(c \cdot z + \left(-i \cdot a\right)\right)}, j \cdot \left(c \cdot t - i \cdot y\right)\right)\right)
\] |
distribute-neg-in [=>]63.8 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \mathsf{fma}\left(b, \color{blue}{\left(-c \cdot z\right) + \left(-\left(-i \cdot a\right)\right)}, j \cdot \left(c \cdot t - i \cdot y\right)\right)\right)
\] |
+-commutative [=>]63.8 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \mathsf{fma}\left(b, \color{blue}{\left(-\left(-i \cdot a\right)\right) + \left(-c \cdot z\right)}, j \cdot \left(c \cdot t - i \cdot y\right)\right)\right)
\] |
remove-double-neg [=>]63.8 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \mathsf{fma}\left(b, \color{blue}{i \cdot a} + \left(-c \cdot z\right), j \cdot \left(c \cdot t - i \cdot y\right)\right)\right)
\] |
sub-neg [<=]63.8 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \mathsf{fma}\left(b, \color{blue}{i \cdot a - c \cdot z}, j \cdot \left(c \cdot t - i \cdot y\right)\right)\right)
\] |
*-commutative [=>]63.8 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \mathsf{fma}\left(b, \color{blue}{a \cdot i} - c \cdot z, j \cdot \left(c \cdot t - i \cdot y\right)\right)\right)
\] |
*-commutative [=>]63.8 | \[ \mathsf{fma}\left(x, y \cdot z - t \cdot a, \mathsf{fma}\left(b, a \cdot i - \color{blue}{z \cdot c}, j \cdot \left(c \cdot t - i \cdot y\right)\right)\right)
\] |
Taylor expanded in x around 0 59.3
Taylor expanded in b around 0 59.3
Simplified25.0
[Start]59.3 | \[ b \cdot \left(i \cdot a - c \cdot z\right) + \left(c \cdot t - i \cdot y\right) \cdot j
\] |
|---|---|
*-commutative [=>]59.3 | \[ b \cdot \left(i \cdot a - c \cdot z\right) + \color{blue}{j \cdot \left(c \cdot t - i \cdot y\right)}
\] |
*-commutative [<=]59.3 | \[ b \cdot \left(i \cdot a - c \cdot z\right) + j \cdot \left(c \cdot t - \color{blue}{y \cdot i}\right)
\] |
cancel-sign-sub-inv [=>]59.3 | \[ b \cdot \left(i \cdot a - c \cdot z\right) + j \cdot \color{blue}{\left(c \cdot t + \left(-y\right) \cdot i\right)}
\] |
distribute-rgt-in [=>]59.3 | \[ b \cdot \left(i \cdot a - c \cdot z\right) + \color{blue}{\left(\left(c \cdot t\right) \cdot j + \left(\left(-y\right) \cdot i\right) \cdot j\right)}
\] |
mul-1-neg [<=]59.3 | \[ b \cdot \left(i \cdot a - c \cdot z\right) + \left(\left(c \cdot t\right) \cdot j + \left(\color{blue}{\left(-1 \cdot y\right)} \cdot i\right) \cdot j\right)
\] |
associate-*r* [<=]51.8 | \[ b \cdot \left(i \cdot a - c \cdot z\right) + \left(\left(c \cdot t\right) \cdot j + \color{blue}{\left(-1 \cdot y\right) \cdot \left(i \cdot j\right)}\right)
\] |
associate-*r* [<=]51.8 | \[ b \cdot \left(i \cdot a - c \cdot z\right) + \left(\left(c \cdot t\right) \cdot j + \color{blue}{-1 \cdot \left(y \cdot \left(i \cdot j\right)\right)}\right)
\] |
associate-*r* [<=]43.6 | \[ b \cdot \left(i \cdot a - c \cdot z\right) + \left(\color{blue}{c \cdot \left(t \cdot j\right)} + -1 \cdot \left(y \cdot \left(i \cdot j\right)\right)\right)
\] |
sub-neg [=>]43.6 | \[ b \cdot \color{blue}{\left(i \cdot a + \left(-c \cdot z\right)\right)} + \left(c \cdot \left(t \cdot j\right) + -1 \cdot \left(y \cdot \left(i \cdot j\right)\right)\right)
\] |
distribute-rgt-neg-out [<=]43.6 | \[ b \cdot \left(i \cdot a + \color{blue}{c \cdot \left(-z\right)}\right) + \left(c \cdot \left(t \cdot j\right) + -1 \cdot \left(y \cdot \left(i \cdot j\right)\right)\right)
\] |
distribute-rgt-out [<=]43.6 | \[ \color{blue}{\left(\left(i \cdot a\right) \cdot b + \left(c \cdot \left(-z\right)\right) \cdot b\right)} + \left(c \cdot \left(t \cdot j\right) + -1 \cdot \left(y \cdot \left(i \cdot j\right)\right)\right)
\] |
*-commutative [<=]43.6 | \[ \left(\left(i \cdot a\right) \cdot b + \color{blue}{b \cdot \left(c \cdot \left(-z\right)\right)}\right) + \left(c \cdot \left(t \cdot j\right) + -1 \cdot \left(y \cdot \left(i \cdot j\right)\right)\right)
\] |
associate-+l+ [=>]43.6 | \[ \color{blue}{\left(i \cdot a\right) \cdot b + \left(b \cdot \left(c \cdot \left(-z\right)\right) + \left(c \cdot \left(t \cdot j\right) + -1 \cdot \left(y \cdot \left(i \cdot j\right)\right)\right)\right)}
\] |
Final simplification5.3
| Alternative 1 | |
|---|---|
| Error | 5.5 |
| Cost | 12680 |
| Alternative 2 | |
|---|---|
| Error | 5.5 |
| Cost | 12680 |
| Alternative 3 | |
|---|---|
| Error | 5.5 |
| Cost | 5704 |
| Alternative 4 | |
|---|---|
| Error | 27.0 |
| Cost | 2796 |
| Alternative 5 | |
|---|---|
| Error | 24.3 |
| Cost | 2796 |
| Alternative 6 | |
|---|---|
| Error | 37.3 |
| Cost | 2688 |
| Alternative 7 | |
|---|---|
| Error | 37.2 |
| Cost | 2688 |
| Alternative 8 | |
|---|---|
| Error | 24.0 |
| Cost | 2664 |
| Alternative 9 | |
|---|---|
| Error | 26.4 |
| Cost | 2536 |
| Alternative 10 | |
|---|---|
| Error | 35.1 |
| Cost | 2408 |
| Alternative 11 | |
|---|---|
| Error | 27.7 |
| Cost | 2404 |
| Alternative 12 | |
|---|---|
| Error | 34.4 |
| Cost | 2016 |
| Alternative 13 | |
|---|---|
| Error | 34.7 |
| Cost | 2016 |
| Alternative 14 | |
|---|---|
| Error | 34.8 |
| Cost | 2016 |
| Alternative 15 | |
|---|---|
| Error | 22.4 |
| Cost | 1876 |
| Alternative 16 | |
|---|---|
| Error | 42.8 |
| Cost | 1765 |
| Alternative 17 | |
|---|---|
| Error | 26.9 |
| Cost | 1744 |
| Alternative 18 | |
|---|---|
| Error | 21.2 |
| Cost | 1744 |
| Alternative 19 | |
|---|---|
| Error | 49.4 |
| Cost | 1640 |
| Alternative 20 | |
|---|---|
| Error | 49.5 |
| Cost | 1572 |
| Alternative 21 | |
|---|---|
| Error | 37.7 |
| Cost | 1369 |
| Alternative 22 | |
|---|---|
| Error | 39.8 |
| Cost | 1368 |
| Alternative 23 | |
|---|---|
| Error | 37.2 |
| Cost | 1368 |
| Alternative 24 | |
|---|---|
| Error | 49.6 |
| Cost | 1112 |
| Alternative 25 | |
|---|---|
| Error | 41.8 |
| Cost | 1104 |
| Alternative 26 | |
|---|---|
| Error | 36.8 |
| Cost | 1104 |
| Alternative 27 | |
|---|---|
| Error | 49.4 |
| Cost | 848 |
| Alternative 28 | |
|---|---|
| Error | 49.2 |
| Cost | 716 |
| Alternative 29 | |
|---|---|
| Error | 50.1 |
| Cost | 585 |
| Alternative 30 | |
|---|---|
| Error | 50.1 |
| Cost | 585 |
| Alternative 31 | |
|---|---|
| Error | 50.6 |
| Cost | 584 |
| Alternative 32 | |
|---|---|
| Error | 49.9 |
| Cost | 584 |
| Alternative 33 | |
|---|---|
| Error | 53.4 |
| Cost | 320 |
herbie shell --seed 2023018
(FPCore (x y z t a b c i j)
:name "Linear.Matrix:det33 from linear-1.19.1.3"
:precision binary64
:herbie-target
(if (< t -8.120978919195912e-33) (- (* x (- (* z y) (* a t))) (- (* b (- (* z c) (* a i))) (* (- (* c t) (* y i)) j))) (if (< t -4.712553818218485e-169) (+ (- (* x (- (* y z) (* t a))) (* b (- (* c z) (* i a)))) (/ (* j (- (pow (* c t) 2.0) (pow (* i y) 2.0))) (+ (* c t) (* i y)))) (if (< t -7.633533346031584e-308) (- (* x (- (* z y) (* a t))) (- (* b (- (* z c) (* a i))) (* (- (* c t) (* y i)) j))) (if (< t 1.0535888557455487e-139) (+ (- (* x (- (* y z) (* t a))) (* b (- (* c z) (* i a)))) (/ (* j (- (pow (* c t) 2.0) (pow (* i y) 2.0))) (+ (* c t) (* i y)))) (- (* x (- (* z y) (* a t))) (- (* b (- (* z c) (* a i))) (* (- (* c t) (* y i)) j)))))))
(+ (- (* x (- (* y z) (* t a))) (* b (- (* c z) (* i a)))) (* j (- (* c t) (* i y)))))