\[x - \frac{y - z}{\frac{\left(t - z\right) + 1}{a}}\]

x - \frac{y - z}{\frac{\left(t - z\right) + 1}{a}}

double f(double x, double y, double z, double t, double a) {
        double r8801 = x;
        double r8802 = y;
        double r8803 = z;
        double r8804 = r8802 - r8803;
        double r8805 = t;
        double r8806 = r8805 - r8803;
        double r8807 = 1.0;
        double r8808 = r8806 + r8807;
        double r8809 = a;
        double r8810 = r8808 / r8809;
        double r8811 = r8804 / r8810;
        double r8812 = r8801 - r8811;
        return r8812;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019191 
(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

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