\[1 - \log \left(1 - \frac{x - y}{1 - y}\right)\]

1 - \log \left(1 - \frac{x - y}{1 - y}\right)

double f(double x, double y) {
        double r199375 = 1.0;
        double r199376 = x;
        double r199377 = y;
        double r199378 = r199376 - r199377;
        double r199379 = r199375 - r199377;
        double r199380 = r199378 / r199379;
        double r199381 = r199375 - r199380;
        double r199382 = log(r199381);
        double r199383 = r199375 - r199382;
        return r199383;
}

Reproduce

Please include this information when filing a bug report:

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

  :herbie-target
  (if (< y -81284752.61947241) (- 1 (log (- (/ x (* y y)) (- (/ 1 y) (/ x y))))) (if (< y 3.0094271212461764e+25) (log (/ (exp 1) (- 1 (/ (- x y) (- 1 y))))) (- 1 (log (- (/ x (* y y)) (- (/ 1 y) (/ x y)))))))

  (- 1 (log (- 1 (/ (- x y) (- 1 y))))))

Backtrace

hash-ref: no value found for key key: '(* #<enode 34(34)> #<enode 0(156)>)		L	C
for-loop	/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/egraph.rkt	270	6
update-leader!	/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/egraph.rkt	265	0
for-loop	/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/main.rkt	77	2
prune-phase	/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/main.rkt	74	0
for-loop	/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/core/simplify.rkt	80	4
for-loop	/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/core/simplify.rkt	76	2
(unnamed)	/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/core/simplify.rkt	56	0
(unnamed)	/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/core/simplify.rkt	38	0
simplify!	/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/mainloop.rkt	224	0
run-iter!	/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/mainloop.rkt	327	0
for-loop	/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/mainloop.rkt	365	4
run-improve47	/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/mainloop.rkt	346	0
.../more-scheme.rkt:261:28	unknown
run	/opt/racket-7.5/share/pkgs/profile-lib/main.rkt	39	2
profile-thunk16	/opt/racket-7.5/share/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/opt/racket-7.5/collects/racket/private/more-scheme.rkt	261	28

Falling back on racket egraph because egg-herbie package not installed (more)

Reproduce

Backtrace