\[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z\]

\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z

double f(double x, double y, double z) {
        double r8581 = x;
        double r8582 = y;
        double r8583 = 0.5;
        double r8584 = r8582 + r8583;
        double r8585 = log(r8582);
        double r8586 = r8584 * r8585;
        double r8587 = r8581 - r8586;
        double r8588 = r8587 + r8582;
        double r8589 = z;
        double r8590 = r8588 - r8589;
        return r8590;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019191 +o rules:numerics
(FPCore (x y z)
  :name "Numeric.SpecFunctions:stirlingError from math-functions-0.1.5.2"

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

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

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