from gPy.Models import BN

class myBN(BN):
	def forward_inference(self):
		marginals = dict()
		for v in self.topological_order():
			marginals[v] = self[v]
			for c in self.parents(v):
				marginals[v] *= marginals[c]
				marginals[v].marginalise_away([c])
		return marginals