-- Adding an arc to the running system

function System.add(arc)
	if not arcInstances[arc] then
		arcInstances[arc] = true
		numInstances = numInstances + 1
		arc.segmentsFolder.Parent = MainFolder
		arc.part.Parent = MainPartFolder
		if arc.dynamic then
			dynamicInstances[arc] = true
		end
		updateConnection()
	end
end

function System.contains(arc)
	return arcInstances[arc] ~= nil
end
