private static void visitSpecialVal(MemoryStateCreator mem,	SpecialValContext tree) {
		switch (tree.getText()) {
			case "SP":
				mem.addSp();				break;
			case "PC":
				mem.addPc();				break;
			case "POP":
				mem.addPop();				break;
			case "PEEK":
				mem.addPeek();				break;
		}
	}