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做一个小例子，我想在某个位置的列表中插入一个符号 

domains
    element = symbol
    list = element*
    position = integer
predicates
    insert (element, position, list, list) %(input,input,input,output)
clauses 
    insert (E,_,[],[E]). 
    insert (E, 1,[H|T],[E|[H|T]]).       %(I insert E on the "first" position)
    % I get errors how E and T are not bound. I have no idea how to make them bound
    insert (E,P,[H|T],[H1|T1]) :-
           P > 1,
           P1 = P - 1,
           insert (E,P1,T,T1).

它不起作用......但我不知道为什么。嗯，它有点工作。我希望它向我展示，outputList = [NEW_LIST]而不是时不时地展示。symbolName=_outputList = [_,_,_,_]

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1 回答 1

0

显然符号数据类型存在一些问题，如果我使用整数，它会自行修复。

此外，这是必不可少的：

domains
    element = integer
     list = element*
     position = integer
predicates
     insert (element, position, list, list) %(input,input,input,output)
clauses 
     insert (E,_,[],[E]). 
     insert (E, 1,[H|T],[E|[H|T]]).
     insert (E,P,[H|T],[H|T1]) :-  % has to be "H" (or anything else) in both
          P > 1,                   % so prolog understands what we are trying to do
          P1 = P - 1,              % don't really understand why though
          insert (E,P1,T,T1).      % I might be wrong
于 2012-11-10T18:22:37.073 回答