Exception for Main:z from

Math

\[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\]

C

double f(double x, double y, double z, double t) {
        double r77096819 = x;
        double r77096820 = 1.0;
        double r77096821 = r77096819 + r77096820;
        double r77096822 = sqrt(r77096821);
        double r77096823 = sqrt(r77096819);
        double r77096824 = r77096822 - r77096823;
        double r77096825 = y;
        double r77096826 = r77096825 + r77096820;
        double r77096827 = sqrt(r77096826);
        double r77096828 = sqrt(r77096825);
        double r77096829 = r77096827 - r77096828;
        double r77096830 = r77096824 + r77096829;
        double r77096831 = z;
        double r77096832 = r77096831 + r77096820;
        double r77096833 = sqrt(r77096832);
        double r77096834 = sqrt(r77096831);
        double r77096835 = r77096833 - r77096834;
        double r77096836 = r77096830 + r77096835;
        double r77096837 = t;
        double r77096838 = r77096837 + r77096820;
        double r77096839 = sqrt(r77096838);
        double r77096840 = sqrt(r77096837);
        double r77096841 = r77096839 - r77096840;
        double r77096842 = r77096836 + r77096841;
        return r77096842;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019173 +o rules:numerics
(FPCore (x y z t)
  :name "Main:z from "

  :herbie-target
  (+ (+ (+ (/ 1.0 (+ (sqrt (+ x 1.0)) (sqrt x))) (/ 1.0 (+ (sqrt (+ y 1.0)) (sqrt y)))) (/ 1.0 (+ (sqrt (+ z 1.0)) (sqrt z)))) (- (sqrt (+ t 1.0)) (sqrt t)))

  (+ (+ (+ (- (sqrt (+ x 1.0)) (sqrt x)) (- (sqrt (+ y 1.0)) (sqrt y))) (- (sqrt (+ z 1.0)) (sqrt z))) (- (sqrt (+ t 1.0)) (sqrt t))))

Backtrace

hash-ref: no value found for key key: #<enode 572(572)>		L	C
for-loop	/data/pavpan/nightlies/herbie/various-cleanup/src/core/simplify.rkt	197	2
extractor-extract	/data/pavpan/nightlies/herbie/various-cleanup/src/core/simplify.rkt	196	0
for-loop	/data/pavpan/nightlies/herbie/various-cleanup/src/core/simplify.rkt	35	2
(unnamed)	/data/pavpan/nightlies/herbie/various-cleanup/src/core/simplify.rkt	26	0
simplify!	/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt	217	0
run-iter!	/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt	320	0
for-loop	/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt	354	4
run-improve43	/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt	339	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