\[-1 \lt x \land x \lt 1\]

\[\frac{\log \left(1 - x\right)}{\log \left(1 + x\right)}\]

\frac{\log \left(1 - x\right)}{\log \left(1 + x\right)}

double f(double x) {
        double r10463 = 1.0;
        double r10464 = x;
        double r10465 = r10463 - r10464;
        double r10466 = log(r10465);
        double r10467 = r10463 + r10464;
        double r10468 = log(r10467);
        double r10469 = r10466 / r10468;
        return r10469;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019310 +o rules:numerics
(FPCore (x)
  :name "qlog (example 3.10)"
  :precision binary64
  :pre (and (< -1 x) (< x 1))

  :herbie-target
  (- (+ (+ (+ 1 x) (/ (* x x) 2)) (* 0.416666666666666685 (pow x 3))))

  (/ (log (- 1 x)) (log (+ 1 x))))

Backtrace

match: no matching clause for 'binary64		L	C
match:error	/opt/racket-7.2/collects/racket/match/runtime.rkt	24	0
for-loop	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/reduce.rkt	246	3
make-multiplication-subnode	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/reduce.rkt	244	0
make-multiplication-node	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/reduce.rkt	234	0
map	/opt/racket-7.2/collects/racket/private/map.rkt	35	13
f45	/opt/racket-7.2/collects/racket/match/compiler.rkt	507	40
simplify	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/reduce.rkt	16	0
(unnamed)	/opt/racket-7.2/collects/racket/contract/private/arrow-higher-order.rkt	360	33
location-do	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/programs.rkt	64	0
location-do	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/programs.rkt	64	0
(unnamed)	/opt/racket-7.2/collects/racket/contract/private/arrow-higher-order.rkt	360	33
for-loop	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt	151	6
taylor-alt	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt	145	0
for-loop	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt	166	7
gen-series!	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt	159	0
run-iter!	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt	326	0
for-loop	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt	364	4
run-improve47	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt	345	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