\[\sqrt{\left(\left(2 \cdot n\right) \cdot U\right) \cdot \left(\left(t - 2 \cdot \frac{\ell \cdot \ell}{Om}\right) - \left(n \cdot {\left(\frac{\ell}{Om}\right)}^{2}\right) \cdot \left(U - U*\right)\right)}\]

\sqrt{\left(\left(2 \cdot n\right) \cdot U\right) \cdot \left(\left(t - 2 \cdot \frac{\ell \cdot \ell}{Om}\right) - \left(n \cdot {\left(\frac{\ell}{Om}\right)}^{2}\right) \cdot \left(U - U*\right)\right)}

double f(double n, double U, double t, double l, double Om, double U_) {
        double r82168 = 2.0;
        double r82169 = n;
        double r82170 = r82168 * r82169;
        double r82171 = U;
        double r82172 = r82170 * r82171;
        double r82173 = t;
        double r82174 = l;
        double r82175 = r82174 * r82174;
        double r82176 = Om;
        double r82177 = r82175 / r82176;
        double r82178 = r82168 * r82177;
        double r82179 = r82173 - r82178;
        double r82180 = r82174 / r82176;
        double r82181 = pow(r82180, r82168);
        double r82182 = r82169 * r82181;
        double r82183 = U_;
        double r82184 = r82171 - r82183;
        double r82185 = r82182 * r82184;
        double r82186 = r82179 - r82185;
        double r82187 = r82172 * r82186;
        double r82188 = sqrt(r82187);
        return r82188;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019323 +o rules:numerics
(FPCore (n U t l Om U*)
  :name "Toniolo and Linder, Equation (13)"
  :precision binary64
  (sqrt (* (* (* 2 n) U) (- (- t (* 2 (/ (* l l) Om))) (* (* n (pow (/ l Om) 2)) (- U U*))))))

Backtrace

dict-ref: no value for key: 'branch82167 in: '((n . binary64) (U . binary64) (t . binary64) (l . binary64) (Om . binary64) (U* . binary64))		L	C
for-loop	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt	106	4
make-sampler	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt	99	0
prepare-points-intervals	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt	121	0
for-loop	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt	233	9
sindices->spoints	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt	194	0
f33	/opt/racket-7.2/collects/racket/match/compiler.rkt	507	40
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