. (). (, .) , () (input), (output), .. . , .. ( ), ( ) - . , member (E, L),
member (E, [E| L]).
member (E, [Z| L]):- member (E, L).
, E L, :
?-member (b, [a, b, c]): , ;
?-member (, [a, b, c]): , ( ) ;
?-member (b, Y): , (Y) - , b.
(/ input/output) (flow pattern), i o, . member : (i, i), (o, i), (i, o). , - , .
- . , (). ( ) . , member (o, i) (i, o).
-:
1. 20 , . , , .
2. subset, path, short_path, min_path (). , path.
3. flatten_tree, short_path, min_path . flatten_tree append ; .
4. , .
5. sort , : (), , , .
6. - , , : free, bound, read, assert, retract .