\[\left(\left(x - \frac{16}{116}\right) \cdot 3\right) \cdot y\]

\left(\left(x - \frac{16}{116}\right) \cdot 3\right) \cdot y

double f(double x, double y) {
        double r9386 = x;
        double r9387 = 16.0;
        double r9388 = 116.0;
        double r9389 = r9387 / r9388;
        double r9390 = r9386 - r9389;
        double r9391 = 3.0;
        double r9392 = r9390 * r9391;
        double r9393 = y;
        double r9394 = r9392 * r9393;
        return r9394;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019194 
(FPCore (x y)
  :name "Data.Colour.CIE:cieLAB from colour-2.3.3, A"

  :herbie-target
  (* y (- (* x 3.0) 0.41379310344827586))

  (* (* (- x (/ 16.0 116.0)) 3.0) y))

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	220	0
run-improve47	/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt	342	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