# Set the dependences for the phi-function
	# *`block` BasicBlock in which we go through the dominance-frontier
	# *`v` The variable to looking for
	fun add_dependences(block: BasicBlock, v: Variable)
	do
		# Look in which blocks of DF(block) `v` has been assigned
		for b in block.predecessors do
			if v.assignment_blocks.has(b) then
				var dep = new Couple[Variable, BasicBlock](v, b)
				dependences.add(dep)
			end
		end
	end