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

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

double code(double x, double y) {
	return ((double) (1.0 - ((double) log(((double) (1.0 - ((double) (((double) (x - y)) / ((double) (1.0 - y))))))))));
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2020128 
(FPCore (x y)
  :name "Numeric.SpecFunctions:invIncompleteGamma from math-functions-0.1.5.2, B"
  :precision binary64

  :herbie-target
  (if (< y -81284752.61947241) (- 1.0 (log (- (/ x (* y y)) (- (/ 1.0 y) (/ x y))))) (if (< y 3.0094271212461764e+25) (log (/ (exp 1.0) (- 1.0 (/ (- x y) (- 1.0 y))))) (- 1.0 (log (- (/ x (* y y)) (- (/ 1.0 y) (/ x y)))))))

  (- 1.0 (log (- 1.0 (/ (- x y) (- 1.0 y))))))

Backtrace

random-bits: contract violation expected: Positive-Integer given: 0		L	C
random-ranges	/data/pavpan/nightlies/herbie/separate-biginterval/src/common.rkt	139	0
sample-multi-bounded	/data/pavpan/nightlies/herbie/separate-biginterval/src/points.rkt	14	0
(unnamed)	/data/pavpan/nightlies/herbie/separate-biginterval/src/points.rkt	127	6
prepare-points-intervals	/data/pavpan/nightlies/herbie/separate-biginterval/src/points.rkt	134	0
pred	/data/pavpan/nightlies/herbie/separate-biginterval/src/core/regimes.rkt	200	4
for-loop	/data/pavpan/nightlies/herbie/separate-biginterval/src/core/regimes.rkt	230	9
sindices->spoints	/data/pavpan/nightlies/herbie/separate-biginterval/src/core/regimes.rkt	190	0
f37	unknown
get-final-combination	/data/pavpan/nightlies/herbie/separate-biginterval/src/mainloop.rkt	390	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

Reproduce

herbie shell --seed 2020128 
(FPCore (x y)
  :name "Numeric.SpecFunctions:invIncompleteGamma from math-functions-0.1.5.2, B"
  :precision binary64

  :herbie-target
  (if (< y -81284752.61947241) (- 1.0 (log (- (/ x (* y y)) (- (/ 1.0 y) (/ x y))))) (if (< y 3.0094271212461764e+25) (log (/ (exp 1.0) (- 1.0 (/ (- x y) (- 1.0 y))))) (- 1.0 (log (- (/ x (* y y)) (- (/ 1.0 y) (/ x y)))))))

  (- 1.0 (log (- 1.0 (/ (- x y) (- 1.0 y))))))