\[-1 < x \land x < 1\]
\[\frac{\log \left(1 - x\right)}{\log \left(1 + x\right)} \]
(FPCore (x) :precision binary64 (/ (log (- 1.0 x)) (log (+ 1.0 x))))
double code(double x) {
	return log((1.0 - x)) / log((1.0 + x));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = log((1.0d0 - x)) / log((1.0d0 + x))
end function
public static double code(double x) {
	return Math.log((1.0 - x)) / Math.log((1.0 + x));
}
def code(x):
	return math.log((1.0 - x)) / math.log((1.0 + x))
function code(x)
	return Float64(log(Float64(1.0 - x)) / log(Float64(1.0 + x)))
end
function tmp = code(x)
	tmp = log((1.0 - x)) / log((1.0 + x));
end
code[x_] := N[(N[Log[N[(1.0 - x), $MachinePrecision]], $MachinePrecision] / N[Log[N[(1.0 + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\frac{\log \left(1 - x\right)}{\log \left(1 + x\right)}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2022349 
(FPCore (x)
  :name "qlog (example 3.10)"
  :precision binary64
  :pre (and (< -1.0 x) (< x 1.0))

  :herbie-target
  (- (+ (+ (+ 1.0 x) (/ (* x x) 2.0)) (* 0.4166666666666667 (pow x 3.0))))

  (/ (log (- 1.0 x)) (log (+ 1.0 x))))

Backtrace

error writing to stream port system error: Broken pipe; errno=32LC
writeln/usr/share/racket/collects/racket/private/misc.rkt1564
run-egglog/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/egglog/run-egglog.rkt13010
run-simplify-input/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/core/simplify.rkt740
simplify-batch/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/core/simplify.rkt510
(unnamed)/usr/share/racket/collects/racket/contract/private/arrow-higher-order.rkt37933
get-swaps/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/symmetry.rkt60
connected-components/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/symmetry.rkt200
run-improve!/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/mainloop.rkt3200
(unnamed)/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/sandbox.rkt556
(unnamed)/usr/share/racket/pkgs/profile-lib/main.rkt4010
profile-thunk/usr/share/racket/pkgs/profile-lib/main.rkt90
(unnamed)/usr/share/racket/collects/racket/engine.rkt4224