\[x - \frac{y - z}{\frac{\left(t - z\right) + 1}{a}}\]
x - \frac{y - z}{\frac{\left(t - z\right) + 1}{a}}
double f(double x, double y, double z, double t, double a) {
        double r377507 = x;
        double r377508 = y;
        double r377509 = z;
        double r377510 = r377508 - r377509;
        double r377511 = t;
        double r377512 = r377511 - r377509;
        double r377513 = 1.0;
        double r377514 = r377512 + r377513;
        double r377515 = a;
        double r377516 = r377514 / r377515;
        double r377517 = r377510 / r377516;
        double r377518 = r377507 - r377517;
        return r377518;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019323 
(FPCore (x y z t a)
  :name "Graphics.Rendering.Chart.SparkLine:renderSparkLine from Chart-1.5.3"
  :precision binary64

  :herbie-target
  (- x (* (/ (- y z) (+ (- t z) 1)) a))

  (- x (/ (- y z) (/ (+ (- t z) 1) a))))

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