public static ITypeResolver arithmType(Type lh, Type rh) {

		int cmp = rh.compare(lh);
		if (cmp > 0) {
			return new PlainOldTypeResolver(rh);
		} else if (cmp == 0) {
			if (rh instanceof PrimType) {
				return new PlainOldTypeResolver(rh);
			}
			return new PlainOldTypeResolver(lh);
		} else if (cmp == -1) {

			return new PlainOldTypeResolver(lh);
		} else {
			return null;
		}
	}