\[\left(\left(\left(\left(\left(x \cdot y - z \cdot t\right) \cdot \left(a \cdot b - c \cdot i\right) - \left(x \cdot j - z \cdot k\right) \cdot \left(y0 \cdot b - y1 \cdot i\right)\right) + \left(x \cdot y2 - z \cdot y3\right) \cdot \left(y0 \cdot c - y1 \cdot a\right)\right) + \left(t \cdot j - y \cdot k\right) \cdot \left(y4 \cdot b - y5 \cdot i\right)\right) - \left(t \cdot y2 - y \cdot y3\right) \cdot \left(y4 \cdot c - y5 \cdot a\right)\right) + \left(k \cdot y2 - j \cdot y3\right) \cdot \left(y4 \cdot y1 - y5 \cdot y0\right)\]

\left(\left(\left(\left(\left(x \cdot y - z \cdot t\right) \cdot \left(a \cdot b - c \cdot i\right) - \left(x \cdot j - z \cdot k\right) \cdot \left(y0 \cdot b - y1 \cdot i\right)\right) + \left(x \cdot y2 - z \cdot y3\right) \cdot \left(y0 \cdot c - y1 \cdot a\right)\right) + \left(t \cdot j - y \cdot k\right) \cdot \left(y4 \cdot b - y5 \cdot i\right)\right) - \left(t \cdot y2 - y \cdot y3\right) \cdot \left(y4 \cdot c - y5 \cdot a\right)\right) + \left(k \cdot y2 - j \cdot y3\right) \cdot \left(y4 \cdot y1 - y5 \cdot y0\right)

double f(double x, double y, double z, double t, double a, double b, double c, double i, double j, double k, double y0, double y1, double y2, double y3, double y4, double y5) {
        double r8398 = x;
        double r8399 = y;
        double r8400 = r8398 * r8399;
        double r8401 = z;
        double r8402 = t;
        double r8403 = r8401 * r8402;
        double r8404 = r8400 - r8403;
        double r8405 = a;
        double r8406 = b;
        double r8407 = r8405 * r8406;
        double r8408 = c;
        double r8409 = i;
        double r8410 = r8408 * r8409;
        double r8411 = r8407 - r8410;
        double r8412 = r8404 * r8411;
        double r8413 = j;
        double r8414 = r8398 * r8413;
        double r8415 = k;
        double r8416 = r8401 * r8415;
        double r8417 = r8414 - r8416;
        double r8418 = y0;
        double r8419 = r8418 * r8406;
        double r8420 = y1;
        double r8421 = r8420 * r8409;
        double r8422 = r8419 - r8421;
        double r8423 = r8417 * r8422;
        double r8424 = r8412 - r8423;
        double r8425 = y2;
        double r8426 = r8398 * r8425;
        double r8427 = y3;
        double r8428 = r8401 * r8427;
        double r8429 = r8426 - r8428;
        double r8430 = r8418 * r8408;
        double r8431 = r8420 * r8405;
        double r8432 = r8430 - r8431;
        double r8433 = r8429 * r8432;
        double r8434 = r8424 + r8433;
        double r8435 = r8402 * r8413;
        double r8436 = r8399 * r8415;
        double r8437 = r8435 - r8436;
        double r8438 = y4;
        double r8439 = r8438 * r8406;
        double r8440 = y5;
        double r8441 = r8440 * r8409;
        double r8442 = r8439 - r8441;
        double r8443 = r8437 * r8442;
        double r8444 = r8434 + r8443;
        double r8445 = r8402 * r8425;
        double r8446 = r8399 * r8427;
        double r8447 = r8445 - r8446;
        double r8448 = r8438 * r8408;
        double r8449 = r8440 * r8405;
        double r8450 = r8448 - r8449;
        double r8451 = r8447 * r8450;
        double r8452 = r8444 - r8451;
        double r8453 = r8415 * r8425;
        double r8454 = r8413 * r8427;
        double r8455 = r8453 - r8454;
        double r8456 = r8438 * r8420;
        double r8457 = r8440 * r8418;
        double r8458 = r8456 - r8457;
        double r8459 = r8455 * r8458;
        double r8460 = r8452 + r8459;
        return r8460;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019179 +o rules:numerics
(FPCore (x y z t a b c i j k y0 y1 y2 y3 y4 y5)
  :name "Linear.Matrix:det44 from linear-1.19.1.3"
  (+ (- (+ (+ (- (* (- (* x y) (* z t)) (- (* a b) (* c i))) (* (- (* x j) (* z k)) (- (* y0 b) (* y1 i)))) (* (- (* x y2) (* z y3)) (- (* y0 c) (* y1 a)))) (* (- (* t j) (* y k)) (- (* y4 b) (* y5 i)))) (* (- (* t y2) (* y y3)) (- (* y4 c) (* y5 a)))) (* (- (* k y2) (* j y3)) (- (* y4 y1) (* y5 y0)))))

Backtrace

result arity mismatch; expected number of values not received expected: 2 received: 1 in: local-binding form values...: 0		L	C
loop	/data/pavpan/nightlies/herbie/various-cleanup/src/core/extraction.rkt	25	2
(unnamed)	/data/pavpan/nightlies/herbie/various-cleanup/src/core/simplify.rkt	26	0
simplify!	/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt	217	0
run-improve43	/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt	339	0
(unnamed)	/opt/racket-7.0/collects/racket/private/more-scheme.rkt	261	28
run	/opt/racket-7.0/share/pkgs/profile-lib/main.rkt	39	2
profile-thunk16	/opt/racket-7.0/share/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/opt/racket-7.0/collects/racket/private/more-scheme.rkt	261	28