\[\alpha > -1 \land \beta > -1\]
\[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
(FPCore (alpha beta)
 :precision binary64
 (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0))
double code(double alpha, double beta) {
	return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    code = (((beta - alpha) / ((alpha + beta) + 2.0d0)) + 1.0d0) / 2.0d0
end function
public static double code(double alpha, double beta) {
	return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
}
def code(alpha, beta):
	return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0
function code(alpha, beta)
	return Float64(Float64(Float64(Float64(beta - alpha) / Float64(Float64(alpha + beta) + 2.0)) + 1.0) / 2.0)
end
function tmp = code(alpha, beta)
	tmp = (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
end
code[alpha_, beta_] := N[(N[(N[(N[(beta - alpha), $MachinePrecision] / N[(N[(alpha + beta), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / 2.0), $MachinePrecision]
\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2022351 
(FPCore (alpha beta)
  :name "Octave 3.8, jcobi/1"
  :precision binary64
  :pre (and (> alpha -1.0) (> beta -1.0))
  (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0))

Backtrace

map: contract violation expected: list? given: 'ExtractedLC
gen-map/usr/share/racket/collects/racket/private/map.rkt2572
run-egglog/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/egglog/run-egglog.rkt13130
run-simplify-input/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/core/simplify.rkt730
simplify-batch/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/core/simplify.rkt480
(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.rkt210
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