\[\left(x + y\right) + x\]
\left(x + y\right) + x
double f(double x, double y) {
        double r9417 = x;
        double r9418 = y;
        double r9419 = r9417 + r9418;
        double r9420 = r9419 + r9417;
        return r9420;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019305 
(FPCore (x y)
  :name "Graphics.Rendering.Plot.Render.Plot.Legend:renderLegendOutside from plot-0.2.3.4, A"
  :precision binary64

  :herbie-target
  (+ y (* 2 x))

  (+ (+ x y) x))

Backtrace

exact?: contract violation expected: number? given: 'h0LC
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