I do not know of any app but there is a site for simple ones.

]]>P(A) = .1

P(B) = .2

P(AUB) = .3

P(A|B) = ?

Some of the problems are really complicated and consist of multiple events (right now the largest one have five, but more is possible).

Is there any tool which knows how to work with probability functions and can construct a new formula upon the given set of known probabilities?

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