function Set.difference(c,e)local b={}for c,e in pairs(c)do b[c]=true end for c,e in pairs(e)do b[c]=nil end return b end return Set

function Set.difference(set, otherSet)
	local newSet = {}
	for key, _ in pairs(set) do
		newSet[key] = true
	end
	for key, _ in pairs(otherSet) do
		newSet[key] = nil
	end
	return newSet
end


return Set
