\[\frac{\left(1 + \frac{1}{\varepsilon}\right) \cdot e^{-\left(1 - \varepsilon\right) \cdot x} - \left(\frac{1}{\varepsilon} - 1\right) \cdot e^{-\left(1 + \varepsilon\right) \cdot x}}{2}\]
\frac{\left(1 + \frac{1}{\varepsilon}\right) \cdot e^{-\left(1 - \varepsilon\right) \cdot x} - \left(\frac{1}{\varepsilon} - 1\right) \cdot e^{-\left(1 + \varepsilon\right) \cdot x}}{2}
double f(double x, double eps) {
        double r58376 = 1.0;
        double r58377 = eps;
        double r58378 = r58376 / r58377;
        double r58379 = r58376 + r58378;
        double r58380 = r58376 - r58377;
        double r58381 = x;
        double r58382 = r58380 * r58381;
        double r58383 = -r58382;
        double r58384 = exp(r58383);
        double r58385 = r58379 * r58384;
        double r58386 = r58378 - r58376;
        double r58387 = r58376 + r58377;
        double r58388 = r58387 * r58381;
        double r58389 = -r58388;
        double r58390 = exp(r58389);
        double r58391 = r58386 * r58390;
        double r58392 = r58385 - r58391;
        double r58393 = 2.0;
        double r58394 = r58392 / r58393;
        return r58394;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019323 +o rules:numerics
(FPCore (x eps)
  :name "NMSE Section 6.1 mentioned, A"
  :precision binary64
  (/ (- (* (+ 1 (/ 1 eps)) (exp (- (* (- 1 eps) x)))) (* (- (/ 1 eps) 1) (exp (- (* (+ 1 eps) x))))) 2))

Backtrace

dict-ref: no value for key: 'branch58375 in: '((x . binary64) (eps . binary64))LC
for-loop/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt1064
make-sampler/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt990
prepare-points-intervals/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt1210
for-loop/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt2339
sindices->spoints/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt1940
f33/opt/racket-7.2/collects/racket/match/compiler.rkt50740
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