# A logical negation operation
class LNot
	super LExpr

	# The argument
	var e: LExpr

	redef fun ~ do return e
	redef fun to_s do return "~{e}"
	redef fun nnf do return e.nnnf
	redef fun nnnf do return e.nnf
	redef fun cnf(v) do
		if e isa LVar then return super
		return e.nnnf.cnf(v)
	end
	redef fun size do return e.size + 1
end