Now we support Chinese/Unicode Atoms/Variables.
Prolog uses lower case letters to compose Atoms, and upper case letters for Variables.
Languages such as Chinese have no meaning of lower/upper cases which makes no way to distinguish
Atoms and Variables.
So we added a prefix "@" in front of a variable to indicate it.
So that we can code:
-: assert(like(a,b)).
-: assert(like(a,c)).
likes(a,@哪一个).
also,
-: assert(喜欢(小明,小红)).
-: assert(喜欢(小明,小黄)).
-: 喜欢(小明,@谁).