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

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

double f(double x, double y, double z, double t, double a) {
        double r388660 = x;
        double r388661 = y;
        double r388662 = z;
        double r388663 = r388661 - r388662;
        double r388664 = t;
        double r388665 = r388664 - r388662;
        double r388666 = 1.0;
        double r388667 = r388665 + r388666;
        double r388668 = a;
        double r388669 = r388667 / r388668;
        double r388670 = r388663 / r388669;
        double r388671 = r388660 - r388670;
        return r388671;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019323 +o rules:numerics
(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 real		L	C
(unnamed)	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt	65	3
filter	/opt/racket-7.2/collects/racket/private/list.rkt	256	2
infer-splitpoints	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt	34	0
get-final-combination	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt	369	0
(unnamed)	/opt/racket-7.2/collects/racket/private/more-scheme.rkt	261	28
run	/opt/racket-7.2/share/pkgs/profile-lib/main.rkt	39	2
profile-thunk16	/opt/racket-7.2/share/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/opt/racket-7.2/collects/racket/private/more-scheme.rkt	261	28