Exception for Quadratic roots, medium range

\[1.1102230246251565 \cdot 10^{-16} < a \land a < 9007199254740992 \land 1.1102230246251565 \cdot 10^{-16} < b \land b < 9007199254740992 \land 1.1102230246251565 \cdot 10^{-16} < c \land c < 9007199254740992\]

Math

\[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a}\]

FPCore

(FPCore (a b c)
 :precision binary64
 (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))

C

double code(double a, double b, double c) {
	return (((double) (((double) -(b)) + ((double) sqrt(((double) (((double) (b * b)) - ((double) (((double) (4.0 * a)) * c)))))))) / ((double) (2.0 * a)));
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2020203 
(FPCore (a b c)
  :name "Quadratic roots, medium range"
  :precision binary64
  :pre (and (< 1.1102230246251565e-16 a 9007199254740992.0) (< 1.1102230246251565e-16 b 9007199254740992.0) (< 1.1102230246251565e-16 c 9007199254740992.0))
  (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))

Backtrace

first: contract violation expected: (and/c list? (not/c empty?)) given: '()		L	C
batch-eval-progs	/data/pavpan/nightlies/herbie/cleanup/src/programs.rkt	107	0
batch-errors	/data/pavpan/nightlies/herbie/cleanup/src/points.rkt	169	0
atab-add-altns	/data/pavpan/nightlies/herbie/cleanup/src/core/alt-table.rkt	194	0
(unnamed)	/opt/racket-7.5/collects/racket/contract/private/arrow-val-first.rkt	486	18
finalize-iter!	/data/pavpan/nightlies/herbie/cleanup/src/mainloop.rkt	273	0
run-iter!	/data/pavpan/nightlies/herbie/cleanup/src/mainloop.rkt	341	0
for-loop	/data/pavpan/nightlies/herbie/cleanup/src/mainloop.rkt	379	4
run-improve41	/data/pavpan/nightlies/herbie/cleanup/src/mainloop.rkt	360	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 2020203 
(FPCore (a b c)
  :name "Quadratic roots, medium range"
  :precision binary64
  :pre (and (< 1.1102230246251565e-16 a 9007199254740992.0) (< 1.1102230246251565e-16 b 9007199254740992.0) (< 1.1102230246251565e-16 c 9007199254740992.0))
  (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))