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

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

double f(double x, double y, double z, double t, double a) {
        double r8808 = x;
        double r8809 = y;
        double r8810 = z;
        double r8811 = r8809 - r8810;
        double r8812 = t;
        double r8813 = r8812 - r8810;
        double r8814 = 1.0;
        double r8815 = r8813 + r8814;
        double r8816 = a;
        double r8817 = r8815 / r8816;
        double r8818 = r8811 / r8817;
        double r8819 = r8808 - r8818;
        return r8819;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019179 
(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

result arity mismatch; expected number of values not received expected: 2 received: 1 in: local-binding form values...: 0		L	C
loop	/data/pavpan/nightlies/herbie/various-cleanup/src/core/extraction.rkt	25	2
(unnamed)	/data/pavpan/nightlies/herbie/various-cleanup/src/core/simplify.rkt	26	0
simplify!	/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt	217	0
run-improve43	/data/pavpan/nightlies/herbie/various-cleanup/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