\[\frac{2}{1 + e^{-2 \cdot x}} - 1\]
\frac{2}{1 + e^{-2 \cdot x}} - 1
double f(double x, double __attribute__((unused)) y) {
        double r29176 = 2.0;
        double r29177 = 1.0;
        double r29178 = -2.0;
        double r29179 = x;
        double r29180 = r29178 * r29179;
        double r29181 = exp(r29180);
        double r29182 = r29177 + r29181;
        double r29183 = r29176 / r29182;
        double r29184 = r29183 - r29177;
        return r29184;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019323 
(FPCore (x y)
  :name "Logistic function from Lakshay Garg"
  :precision binary64
  (- (/ 2 (+ 1 (exp (* -2 x)))) 1))

Backtrace

get-representation: Unknown representation realLC
(unnamed)/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt653
filter/opt/racket-7.2/collects/racket/private/list.rkt2562
infer-splitpoints/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt340
get-final-combination/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt3690
(unnamed)/opt/racket-7.2/collects/racket/private/more-scheme.rkt26128
run/opt/racket-7.2/share/pkgs/profile-lib/main.rkt392
profile-thunk16/opt/racket-7.2/share/pkgs/profile-lib/main.rkt90
(unnamed)/opt/racket-7.2/collects/racket/private/more-scheme.rkt26128