我有一个事实数据库:
female(mary). female(liz). female(mia). female(tina). female(ann). female(sue).
male(mike). male(jack). male(fred). male(tom). male(joe). male(jim).
parent(mary, mia). parent(mary, fred). parent(mary, tina).
parent(mike, mia). parent(mike, fred). parent(mike, tina).
parent(liz, tom). parent(liz, joe).
parent(jack, tom). parent(jack, joe).
parent(mia, ann).
parent(tina, sue). parent(tina, jim).
parent(tom, sue). parent(tom, jim).
我定义了
mother
mother(M, C) :- parent(M, C), female(M).
谓词按预期工作:
?- mother(liz, tom).
true .
?- mother(liz, fred).
false.
liz mother tom
op(1111, xfx, mother).
这就给了我一个错误:
ERROR: /home/user/prolog/family.pl:13:
No permission to modify static procedure `op/3'
我不知道我做错了什么。
根据要求,以下是一个列表中的完整文件:
female(mary). female(liz). female(mia). female(tina). female(ann). female(sue).
male(mike). male(jack). male(fred). male(tom). male(joe). male(jim).
parent(mary, mia). parent(mary, fred). parent(mary, tina).
parent(mike, mia). parent(mike, fred). parent(mike, tina).
parent(liz, tom). parent(liz, joe).
parent(jack, tom). parent(jack, joe).
parent(mia, ann).
parent(tina, sue). parent(tina, jim).
parent(tom, sue). parent(tom, jim).
mother(M, C) :- parent(M, C), female(M).
op(1111, xfx, mother).
