\[\left(x \cdot \log y + z \cdot \log \left(1 - y\right)\right) - t\]

\left(x \cdot \log y + z \cdot \log \left(1 - y\right)\right) - t

double f(double x, double y, double z, double t) {
        double r8669 = x;
        double r8670 = y;
        double r8671 = log(r8670);
        double r8672 = r8669 * r8671;
        double r8673 = z;
        double r8674 = 1.0;
        double r8675 = r8674 - r8670;
        double r8676 = log(r8675);
        double r8677 = r8673 * r8676;
        double r8678 = r8672 + r8677;
        double r8679 = t;
        double r8680 = r8678 - r8679;
        return r8680;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019194 
(FPCore (x y z t)
  :name "Numeric.SpecFunctions:invIncompleteBetaWorker from math-functions-0.1.5.2, B"

  :herbie-target
  (- (* (- z) (+ (+ (* 0.5 (* y y)) y) (* (/ 0.3333333333333333 (* 1.0 (* 1.0 1.0))) (* y (* y y))))) (- t (* x (log y))))

  (- (+ (* x (log y)) (* z (log (- 1.0 y)))) 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