\[x - \frac{y - z}{\frac{\left(t - z\right) + 1}{a}}\]
x - \frac{y - z}{\frac{\left(t - z\right) + 1}{a}}
double f(double x, double y, double z, double t, double a) {
        double r160403909 = x;
        double r160403910 = y;
        double r160403911 = z;
        double r160403912 = r160403910 - r160403911;
        double r160403913 = t;
        double r160403914 = r160403913 - r160403911;
        double r160403915 = 1.0;
        double r160403916 = r160403914 + r160403915;
        double r160403917 = a;
        double r160403918 = r160403916 / r160403917;
        double r160403919 = r160403912 / r160403918;
        double r160403920 = r160403909 - r160403919;
        return r160403920;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019173 +o rules:numerics
(FPCore (x y z t a)
  :name "Graphics.Rendering.Chart.SparkLine:renderSparkLine from Chart-1.5.3"

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

  (- x (/ (- y z) (/ (+ (- t z) 1.0) a))))

Backtrace

hash-ref: no value found for key key: #<enode 387(387)>LC
for-loop/data/pavpan/nightlies/herbie/various-cleanup/src/core/simplify.rkt1972
extractor-extract/data/pavpan/nightlies/herbie/various-cleanup/src/core/simplify.rkt1960
for-loop/data/pavpan/nightlies/herbie/various-cleanup/src/core/simplify.rkt352
(unnamed)/data/pavpan/nightlies/herbie/various-cleanup/src/core/simplify.rkt260
simplify!/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt2170
run-iter!/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt3200
for-loop/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt3544
run-improve43/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt3390
(unnamed)/opt/racket-7.0/collects/racket/private/more-scheme.rkt26128
run/opt/racket-7.0/share/pkgs/profile-lib/main.rkt392
profile-thunk16/opt/racket-7.0/share/pkgs/profile-lib/main.rkt90
(unnamed)/opt/racket-7.0/collects/racket/private/more-scheme.rkt26128