import mir.math.common: approxEqual;

assert(0.5.betaProportionInvCDF(0.5, 2).approxEqual(0.5));
assert(0.9375.betaProportionInvCDF((1.0 / 3), 3).approxEqual(0.75));
assert(0.8588867.betaProportionInvCDF((1.0 / 9), 4.5).approxEqual(0.25));