\[x \cdot x - \left(y \cdot 4\right) \cdot \left(z \cdot z - t\right)\]

x \cdot x - \left(y \cdot 4\right) \cdot \left(z \cdot z - t\right)

double f(double x, double y, double z, double t) {
        double r8805 = x;
        double r8806 = r8805 * r8805;
        double r8807 = y;
        double r8808 = 4.0;
        double r8809 = r8807 * r8808;
        double r8810 = z;
        double r8811 = r8810 * r8810;
        double r8812 = t;
        double r8813 = r8811 - r8812;
        double r8814 = r8809 * r8813;
        double r8815 = r8806 - r8814;
        return r8815;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019194 
(FPCore (x y z t)
  :name "Graphics.Rasterific.Shading:$sradialGradientWithFocusShader from Rasterific-0.6.1, B"

  :herbie-target
  (- (* x x) (* 4.0 (* y (- (* z z) t))))

  (- (* x x) (* (* y 4.0) (- (* z z) t))))

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	220	0
run-improve47	/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt	342	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