\[0.0 \lt c_p \land 0.0 \lt c_n\]

\[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c_n}}\]

\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c_n}}

double f(double c_p, double c_n, double t, double s) {
        double r212698 = 1.0;
        double r212699 = s;
        double r212700 = -r212699;
        double r212701 = exp(r212700);
        double r212702 = r212698 + r212701;
        double r212703 = r212698 / r212702;
        double r212704 = c_p;
        double r212705 = pow(r212703, r212704);
        double r212706 = r212698 - r212703;
        double r212707 = c_n;
        double r212708 = pow(r212706, r212707);
        double r212709 = r212705 * r212708;
        double r212710 = t;
        double r212711 = -r212710;
        double r212712 = exp(r212711);
        double r212713 = r212698 + r212712;
        double r212714 = r212698 / r212713;
        double r212715 = pow(r212714, r212704);
        double r212716 = r212698 - r212714;
        double r212717 = pow(r212716, r212707);
        double r212718 = r212715 * r212717;
        double r212719 = r212709 / r212718;
        return r212719;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019196 
(FPCore (c_p c_n t s)
  :name "Harley's example"
  :pre (and (< 0.0 c_p) (< 0.0 c_n))

  :herbie-target
  (* (pow (/ (+ 1.0 (exp (- t))) (+ 1.0 (exp (- s)))) c_p) (pow (/ (+ 1.0 (exp t)) (+ 1.0 (exp s))) c_n))

  (/ (* (pow (/ 1.0 (+ 1.0 (exp (- s)))) c_p) (pow (- 1.0 (/ 1.0 (+ 1.0 (exp (- s))))) c_n)) (* (pow (/ 1.0 (+ 1.0 (exp (- t)))) c_p) (pow (- 1.0 (/ 1.0 (+ 1.0 (exp (- t))))) c_n))))

Backtrace

get-representation: Unknown representation #f		L	C
(unnamed)	/data/pavpan/nightlies/herbie/master/src/core/localize.rkt	23	13
hash-ref!	/opt/racket-7.0/collects/racket/private/more-scheme.rkt	376	2
map	/opt/racket-7.0/collects/racket/private/map.rkt	35	13
parse-loop30	/opt/racket-7.0/collects/racket/match/compiler.rkt	418	15
hash-ref!	/opt/racket-7.0/collects/racket/private/more-scheme.rkt	376	2
map	/opt/racket-7.0/collects/racket/private/map.rkt	35	13
parse-loop30	/opt/racket-7.0/collects/racket/match/compiler.rkt	418	15
hash-ref!	/opt/racket-7.0/collects/racket/private/more-scheme.rkt	376	2
localize-error	/data/pavpan/nightlies/herbie/master/src/core/localize.rkt	61	0
localize!	/data/pavpan/nightlies/herbie/master/src/mainloop.rkt	123	0
run-iter!	/data/pavpan/nightlies/herbie/master/src/mainloop.rkt	323	0
for-loop	/data/pavpan/nightlies/herbie/master/src/mainloop.rkt	359	4
run-improve47	/data/pavpan/nightlies/herbie/master/src/mainloop.rkt	342	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

could not determine a ground truth for program body (more)

Reproduce

Backtrace