fig17_2.pl

来自「超多的prolog源代码 具体内容见压缩包里面的programs.txt」· PL 代码 · 共 12 行

%  Figure 17.2  A definition of the planning space for the blocks world.
%  Note: For compatibility with Sicstus Prolog, predicate block/1 in Figure 17.2
%  is here replaced by is_block/1.

% Definition of action move( Block, From, To) in blocks world

% can( Action, Condition): Action possible if Condition true

can( move( Block, From, To), [ clear( Block), clear( To), on( Block, From)] ) :-
  is_block( Block),      % Block to be moved
  object( To),           % "To" is a block or a place
  To \== Block,          % Block cannot b