\[\frac{x}{x + 1} - \frac{x + 1}{x - 1}\]
\frac{x}{x + 1} - \frac{x + 1}{x - 1}
double code(double x) {
	return ((double) (((double) (x / ((double) (x + 1.0)))) - ((double) (((double) (x + 1.0)) / ((double) (x - 1.0))))));
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2020128 
(FPCore (x)
  :name "Asymptote C"
  :precision binary64
  (- (/ x (+ x 1.0)) (/ (+ x 1.0) (- x 1.0))))

Backtrace

random-bits: contract violation expected: Positive-Integer given: 0LC
random-ranges/data/pavpan/nightlies/herbie/separate-biginterval/src/common.rkt1390
sample-multi-bounded/data/pavpan/nightlies/herbie/separate-biginterval/src/points.rkt140
(unnamed)/data/pavpan/nightlies/herbie/separate-biginterval/src/points.rkt1276
prepare-points-intervals/data/pavpan/nightlies/herbie/separate-biginterval/src/points.rkt1340
pred/data/pavpan/nightlies/herbie/separate-biginterval/src/core/regimes.rkt2004
for-loop/data/pavpan/nightlies/herbie/separate-biginterval/src/core/regimes.rkt2309
sindices->spoints/data/pavpan/nightlies/herbie/separate-biginterval/src/core/regimes.rkt1900
f37unknown
get-final-combination/data/pavpan/nightlies/herbie/separate-biginterval/src/mainloop.rkt3900
.../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

Reproduce

herbie shell --seed 2020128 
(FPCore (x)
  :name "Asymptote C"
  :precision binary64
  (- (/ x (+ x 1.0)) (/ (+ x 1.0) (- x 1.0))))