\[\left(\left(x \cdot y - y \cdot y\right) + y \cdot y\right) - y \cdot z\]
\left(\left(x \cdot y - y \cdot y\right) + y \cdot y\right) - y \cdot z
double f(double x, double y, double z) {
        double r8791 = x;
        double r8792 = y;
        double r8793 = r8791 * r8792;
        double r8794 = r8792 * r8792;
        double r8795 = r8793 - r8794;
        double r8796 = r8795 + r8794;
        double r8797 = z;
        double r8798 = r8792 * r8797;
        double r8799 = r8796 - r8798;
        return r8799;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019179 
(FPCore (x y z)
  :name "Linear.Quaternion:$c/ from linear-1.19.1.3, D"

  :herbie-target
  (* (- x z) y)

  (- (+ (- (* x y) (* y y)) (* y y)) (* y z)))

Backtrace

result arity mismatch; expected number of values not received expected: 2 received: 1 in: local-binding form values...: 0LC
loop/data/pavpan/nightlies/herbie/various-cleanup/src/core/extraction.rkt252
(unnamed)/data/pavpan/nightlies/herbie/various-cleanup/src/core/simplify.rkt260
simplify!/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt2170
run-improve43/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt3390
(unnamed)/opt/racket-7.0/collects/racket/private/more-scheme.rkt26128
run/opt/racket-7.0/share/pkgs/profile-lib/main.rkt392
profile-thunk16/opt/racket-7.0/share/pkgs/profile-lib/main.rkt90
(unnamed)/opt/racket-7.0/collects/racket/private/more-scheme.rkt26128