if (!a.value.equals(b.value))
if (a.value.getClass() != b.value.getClass() || !a.value.equals(b.value))
	public static Constant merge(Constant a, Constant b) {		if (!a.isConstant() || !b.isConstant())			return NOT_CONSTANT;		if (!a.value.equals(b.value))			return NOT_CONSTANT;		return a;	}