\[\frac{NdChar}{1 + e^{\frac{-\left(\left(\left(Ec - Vef\right) - EDonor\right) - mu\right)}{KbT}}} + \frac{NaChar}{1 + e^{\frac{\left(\left(Ev + Vef\right) + EAccept\right) + \left(-mu\right)}{KbT}}}\]

\frac{NdChar}{1 + e^{\frac{-\left(\left(\left(Ec - Vef\right) - EDonor\right) - mu\right)}{KbT}}} + \frac{NaChar}{1 + e^{\frac{\left(\left(Ev + Vef\right) + EAccept\right) + \left(-mu\right)}{KbT}}}

double f(double NdChar, double Ec, double Vef, double EDonor, double mu, double KbT, double NaChar, double Ev, double EAccept) {
        double r8694 = NdChar;
        double r8695 = 1.0;
        double r8696 = Ec;
        double r8697 = Vef;
        double r8698 = r8696 - r8697;
        double r8699 = EDonor;
        double r8700 = r8698 - r8699;
        double r8701 = mu;
        double r8702 = r8700 - r8701;
        double r8703 = -r8702;
        double r8704 = KbT;
        double r8705 = r8703 / r8704;
        double r8706 = exp(r8705);
        double r8707 = r8695 + r8706;
        double r8708 = r8694 / r8707;
        double r8709 = NaChar;
        double r8710 = Ev;
        double r8711 = r8710 + r8697;
        double r8712 = EAccept;
        double r8713 = r8711 + r8712;
        double r8714 = -r8701;
        double r8715 = r8713 + r8714;
        double r8716 = r8715 / r8704;
        double r8717 = exp(r8716);
        double r8718 = r8695 + r8717;
        double r8719 = r8709 / r8718;
        double r8720 = r8708 + r8719;
        return r8720;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019191 +o rules:numerics
(FPCore (NdChar Ec Vef EDonor mu KbT NaChar Ev EAccept)
  :name "Bulmash initializePoisson"
  (+ (/ NdChar (+ 1.0 (exp (/ (- (- (- (- Ec Vef) EDonor) mu)) KbT)))) (/ NaChar (+ 1.0 (exp (/ (+ (+ (+ Ev Vef) EAccept) (- mu)) KbT))))))

Backtrace

get-representation: Unknown representation #f		L	C
loop	/data/pavpan/nightlies/herbie/interface2/src/points.rkt	122	4
prepare-points	/data/pavpan/nightlies/herbie/interface2/src/points.rkt	146	0
setup-prog!34	/data/pavpan/nightlies/herbie/interface2/src/mainloop.rkt	67	0
run-improve43	/data/pavpan/nightlies/herbie/interface2/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