\[x + \frac{\left(y - x\right) \cdot \left(z - t\right)}{a - t}\]
x + \frac{\left(y - x\right) \cdot \left(z - t\right)}{a - t}
double f(double x, double y, double z, double t, double a) {
        double r8580 = x;
        double r8581 = y;
        double r8582 = r8581 - r8580;
        double r8583 = z;
        double r8584 = t;
        double r8585 = r8583 - r8584;
        double r8586 = r8582 * r8585;
        double r8587 = a;
        double r8588 = r8587 - r8584;
        double r8589 = r8586 / r8588;
        double r8590 = r8580 + r8589;
        return r8590;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019191 
(FPCore (x y z t a)
  :name "Graphics.Rendering.Chart.Axis.Types:linMap from Chart-1.5.3"

  :herbie-target
  (if (< a -1.6153062845442575e-142) (+ x (* (/ (- y x) 1.0) (/ (- z t) (- a t)))) (if (< a 3.774403170083174e-182) (- y (* (/ z t) (- y x))) (+ x (* (/ (- y x) 1.0) (/ (- z t) (- a t))))))

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

Backtrace

get-representation: Unknown representation #fLC
loop/data/pavpan/nightlies/herbie/interface2/src/points.rkt1224
prepare-points/data/pavpan/nightlies/herbie/interface2/src/points.rkt1460
setup-prog!34/data/pavpan/nightlies/herbie/interface2/src/mainloop.rkt670
run-improve43/data/pavpan/nightlies/herbie/interface2/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