\[\left(\left(x \cdot y - y \cdot z\right) - y \cdot y\right) + y \cdot y\]

\left(\left(x \cdot y - y \cdot z\right) - y \cdot y\right) + y \cdot y

double f(double x, double y, double z) {
        double r8839 = x;
        double r8840 = y;
        double r8841 = r8839 * r8840;
        double r8842 = z;
        double r8843 = r8840 * r8842;
        double r8844 = r8841 - r8843;
        double r8845 = r8840 * r8840;
        double r8846 = r8844 - r8845;
        double r8847 = r8846 + r8845;
        return r8847;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019191 +o rules:numerics
(FPCore (x y z)
  :name "Linear.Quaternion:$c/ from linear-1.19.1.3, B"

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

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

Backtrace

get-representation: Unknown representation #f		L	C
loop	/data/pavpan/nightlies/herbie/interface2/src/points.rkt	122	4
prepare-points	/data/pavpan/nightlies/herbie/interface2/src/points.rkt	146	0
setup-prog!34	/data/pavpan/nightlies/herbie/interface2/src/mainloop.rkt	67	0
run-improve43	/data/pavpan/nightlies/herbie/interface2/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