Please include this information when filing a bug report:
herbie shell --seed 2019067
(FPCore (alpha beta i)
:name "Octave 3.8, jcobi/2"
:pre (and (>.p16 alpha (real->posit16 -1)) (>.p16 beta (real->posit16 -1)) (>.p16 i (real->posit16 0)))
(/.p16 (+.p16 (/.p16 (/.p16 (*.p16 (+.p16 alpha beta) (-.p16 beta alpha)) (+.p16 (+.p16 alpha beta) (*.p16 (real->posit16 2) i))) (+.p16 (+.p16 (+.p16 alpha beta) (*.p16 (real->posit16 2) i)) (real->posit16 2.0))) (real->posit16 1.0)) (real->posit16 2.0)))
| build-list: contract violation expected: exact-nonnegative-integer? given: '(0) | L | C | |
|---|---|---|---|
| build-list | /opt/racket-7.0/collects/racket/private/list.rkt | 296 | 2 |
| debug-print | /data/pavpan/nightlies/herbie/develop/src/debug.rkt | 107 | 0 |
| run-improve43 | /data/pavpan/nightlies/herbie/develop/src/mainloop.rkt | 346 | 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 |