\[x \cdot \left(\frac{y}{z} - \frac{t}{1 - z}\right)\]
x \cdot \left(\frac{y}{z} - \frac{t}{1 - z}\right)
double f(double x, double y, double z, double t) {
        double r253142 = x;
        double r253143 = y;
        double r253144 = z;
        double r253145 = r253143 / r253144;
        double r253146 = t;
        double r253147 = 1.0;
        double r253148 = r253147 - r253144;
        double r253149 = r253146 / r253148;
        double r253150 = r253145 - r253149;
        double r253151 = r253142 * r253150;
        return r253151;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019323 
(FPCore (x y z t)
  :name "Numeric.SpecFunctions:invIncompleteBetaWorker from math-functions-0.1.5.2, C"
  :precision binary64

  :herbie-target
  (if (< (* x (- (/ y z) (/ t (- 1 z)))) -7.623226303312042e-196) (* x (- (/ y z) (* t (/ 1 (- 1 z))))) (if (< (* x (- (/ y z) (/ t (- 1 z)))) 1.4133944927702302e-211) (+ (/ (* y x) z) (- (/ (* t x) (- 1 z)))) (* x (- (/ y z) (* t (/ 1 (- 1 z)))))))

  (* x (- (/ y z) (/ t (- 1 z)))))

Backtrace

dict-ref: no value for key: 'branch253141 in: '((x . binary64) (y . binary64) (z . binary64) (t . binary64))LC
for-loop/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt1064
make-sampler/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt990
prepare-points-intervals/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt1210
for-loop/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt2339
sindices->spoints/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt1940
f33/opt/racket-7.2/collects/racket/match/compiler.rkt50740
get-final-combination/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt3690
(unnamed)/opt/racket-7.2/collects/racket/private/more-scheme.rkt26128
run/opt/racket-7.2/share/pkgs/profile-lib/main.rkt392
profile-thunk16/opt/racket-7.2/share/pkgs/profile-lib/main.rkt90
(unnamed)/opt/racket-7.2/collects/racket/private/more-scheme.rkt26128