\[x \cdot x - \left(y \cdot 4\right) \cdot \left(z \cdot z - t\right)\]
x \cdot x - \left(y \cdot 4\right) \cdot \left(z \cdot z - t\right)
double f(double x, double y, double z, double t) {
        double r9282 = x;
        double r9283 = r9282 * r9282;
        double r9284 = y;
        double r9285 = 4.0;
        double r9286 = r9284 * r9285;
        double r9287 = z;
        double r9288 = r9287 * r9287;
        double r9289 = t;
        double r9290 = r9288 - r9289;
        double r9291 = r9286 * r9290;
        double r9292 = r9283 - r9291;
        return r9292;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019305 
(FPCore (x y z t)
  :name "Graphics.Rasterific.Shading:$sradialGradientWithFocusShader from Rasterific-0.6.1, B"
  :precision binary64

  :herbie-target
  (- (* x x) (* 4 (* y (- (* z z) t))))

  (- (* x x) (* (* y 4) (- (* z z) t))))

Backtrace

exact?: contract violation expected: number? given: 'h3LC
egg-parsed->expr/data/pavpan/nightlies/herbie/eggmath-testversion/src/core/eggmath.rkt650
for-loop/data/pavpan/nightlies/herbie/eggmath-testversion/src/core/eggmath.rkt706
egg-parsed->expr/data/pavpan/nightlies/herbie/eggmath-testversion/src/core/eggmath.rkt650
for-loop/data/pavpan/nightlies/herbie/eggmath-testversion/src/core/eggmath.rkt706
egg-parsed->expr/data/pavpan/nightlies/herbie/eggmath-testversion/src/core/eggmath.rkt650
(unnamed)/data/pavpan/nightlies/herbie/eggmath-testversion/src/core/simplify.rkt498
egraph-add-exprs/data/pavpan/nightlies/herbie/eggmath-testversion/src/core/eggmath.rkt1220
egraph-run/data/pavpan/nightlies/herbie/eggmath-testversion/src/core/eggmath.rkt550
(unnamed)/data/pavpan/nightlies/herbie/eggmath-testversion/src/core/simplify.rkt380
simplify!/data/pavpan/nightlies/herbie/eggmath-testversion/src/mainloop.rkt2230
run-improve47/data/pavpan/nightlies/herbie/eggmath-testversion/src/mainloop.rkt3450
(unnamed)/opt/racket-7.2/collects/racket/private/more-scheme.rkt26128
run/opt/racket-7.2/share/pkgs/profile-lib/main.rkt392
profile-thunk16/opt/racket-7.2/share/pkgs/profile-lib/main.rkt90
(unnamed)/opt/racket-7.2/collects/racket/private/more-scheme.rkt26128