\[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z\]
\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z
double f(double x, double y, double z) {
        double r138536 = x;
        double r138537 = y;
        double r138538 = 0.5;
        double r138539 = r138537 + r138538;
        double r138540 = log(r138537);
        double r138541 = r138539 * r138540;
        double r138542 = r138536 - r138541;
        double r138543 = r138542 + r138537;
        double r138544 = z;
        double r138545 = r138543 - r138544;
        return r138545;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2020045 
(FPCore (x y z)
  :name "Numeric.SpecFunctions:stirlingError from math-functions-0.1.5.2"
  :precision binary64

  :herbie-target
  (- (- (+ y x) z) (* (+ y 0.5) (log y)))

  (- (+ (- x (* (+ y 0.5) (log y))) y) z))

Backtrace

hash-ref: no value found for key key: '(* #<enode 140(140)> #<enode 16(354)>)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-upwards-no-duplicates/src/core/simplify.rkt804
for-loop/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/core/simplify.rkt762
(unnamed)/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/core/simplify.rkt560
(unnamed)/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/core/simplify.rkt380
simplify!/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/mainloop.rkt2240
run-iter!/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/mainloop.rkt3270
for-loop/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/mainloop.rkt3654
run-improve47/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/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