<> 在序言中是什么意思?

what does <> mean in prolog?

示例:

PREDICATES
nondeterm likes (symbol,symbol)

CLAUSES
likes (ali,football).
likes (ali,tenis).
likes (ahmad,tenis).
likes (ahmad,handball).
likes (samir,handball).
likes (samir,swimming).
likes (khaled,horseriding).

GOAL
%
likes (Person, G1), likes (Person,G2), G1<>G2.

在该示例中,<> 表示“不相等”。查询:

likes(Person, G1),
likes(Person, G2),
G1 <> G2.

就是想找一个Person喜欢两个东西的。如果没有 <>G1G2 可能彼此相等,查询可能会找到只喜欢一件事的 Person

<> 可能特定于 Visual Prolog。在其他 Prolog 环境中,您将使用 \=\== 代替。