

我可摸以map < in a model such that < will be = iff LHS and RHS are a
a will be greater than every element of natural number
其他情況同平時一樣
+ is just the same as usual in natural number but a + 任何元素都等於自己
* is just the same as usual in natural number but a multiply by 0等於0,by其他元素都等於自己
E(a, x)點都係等於自己
Sa 都係等於自己