Exception for Kahan p13 Example 3

Math

\[1 - \frac{1}{2 + \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right) \cdot \left(2 - \frac{\frac{2}{t}}{1 + \frac{1}{t}}\right)}\]

C

double f(double t) {
        double r8218 = 1.0;
        double r8219 = 2.0;
        double r8220 = t;
        double r8221 = r8219 / r8220;
        double r8222 = r8218 / r8220;
        double r8223 = r8218 + r8222;
        double r8224 = r8221 / r8223;
        double r8225 = r8219 - r8224;
        double r8226 = r8225 * r8225;
        double r8227 = r8219 + r8226;
        double r8228 = r8218 / r8227;
        double r8229 = r8218 - r8228;
        return r8229;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019191 
(FPCore (t)
  :name "Kahan p13 Example 3"
  (- 1.0 (/ 1.0 (+ 2.0 (* (- 2.0 (/ (/ 2.0 t) (+ 1.0 (/ 1.0 t)))) (- 2.0 (/ (/ 2.0 t) (+ 1.0 (/ 1.0 t)))))))))

Backtrace

get-representation: Unknown representation #f		L	C
loop	/data/pavpan/nightlies/herbie/interface2/src/points.rkt	122	4
prepare-points	/data/pavpan/nightlies/herbie/interface2/src/points.rkt	146	0
setup-prog!34	/data/pavpan/nightlies/herbie/interface2/src/mainloop.rkt	67	0
run-improve43	/data/pavpan/nightlies/herbie/interface2/src/mainloop.rkt	339	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