import mir.math.common: approxEqual;

assert(0.5.betaProportionPDF(0.5, 2) == 1);
assert(0.75.betaProportionPDF((1.0 / 3), 3).approxEqual(0.5));
assert(0.25.betaProportionPDF((1.0 / 9), 4.5).approxEqual(0.9228516));