\[\frac{e^{x} - e^{-x}}{2}\]
\frac{e^{x} - e^{-x}}{2}
double f(double x) {
        double r10830 = x;
        double r10831 = exp(r10830);
        double r10832 = -r10830;
        double r10833 = exp(r10832);
        double r10834 = r10831 - r10833;
        double r10835 = 2.0;
        double r10836 = r10834 / r10835;
        return r10836;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2020045 
(FPCore (x)
  :name "Hyperbolic sine"
  :precision binary64
  (/ (- (exp x) (exp (- x))) 2))

Backtrace

hash-ref: no value found for key key: '(* #<enode 40(40)> #<enode 38(39)>)LC
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/egraph.rkt2706
update-leader!/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/egraph.rkt2650
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/main.rkt772
prune-phase/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/main.rkt740
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt804
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt762
(unnamed)/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt560
(unnamed)/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt380
simplify!/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/mainloop.rkt2240
run-iter!/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/mainloop.rkt3270
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/mainloop.rkt3654
run-improve47/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/mainloop.rkt3460
.../more-scheme.rkt:261:28unknown
run/opt/racket-7.5/share/pkgs/profile-lib/main.rkt392
profile-thunk16/opt/racket-7.5/share/pkgs/profile-lib/main.rkt90
(unnamed)/opt/racket-7.5/collects/racket/private/more-scheme.rkt26128