Consider a family of two children. Given that there is a boy in the family, what is the probability that there are two boys in the family?

data Child Source

type Family = [Child]Source

birth :: Trans Family Source

family :: Dist Family Source

boys :: Int -> Event Family Source

existsBoy :: Event Family Source

familyWithBoy :: Dist Family Source

twoBoys :: Probability Source

countBoys :: Family -> Int Source

numBoys :: Dist Int Source