The invention involves a classical computer that runs a special computer program. The program takes as input an initial data-set that contains probabilistic information and returns as output a sequence of elementary operations (SEO). The initial data-set helps determine a classical Bayesian (CB) net. A program called "Q-Embedder" embeds the CB net within a quantum Bayesian (QB) net. A program called "Qubiter" (a quantum compiler) then translates the QB net into an equivalent SEO. The SEO outputted by the classical computer can be used to manipulate an array of qubits in a quantum computer. Application of the SEO to the array, followed by a measurement of the array, yields the value of certain conditional probabilities that we wish to know. The main goal of the invention is to provide a method for performing classical Bayesian net calculations on a quantum computer. Such calculations can be done on a classical computer; the hope is that they can be done much faster on a quantum computer.