| creates a list with all solutions of a goal for all instantiations of
the free variables in that goal.
bagof(+Term, +(Template ^ Goal), ?TermList)
bagof(+Term, +Goal, ?TermList)
bagof/3 unifies TermList for each different instantiation of
the free variables in Goal with a list of all instantiations
of Term where Goal is a solution of Term.
Each variable, wich occurs in Goal and does not occur in
Term or Template is called a free variable.
Arguments
Term term
Template term
Goal goal
TermList list
Examples
part_of(house, window).
part_of(house, door).
part_of(house, room).
part_of(room, table).
part_of(room, floor).
part_of(floor, tile).
contains(X, Y) :- part_of(X, Y).
contains(X, Y) :- part_of(X, Z), contains(Z, Y).
?- bagof(Element, contains(What, Element), List).
Element = _1
What = house
List = [window,door,room,table,floor,tile];
Element = _1
What = room
List = [table,floor,tile];
Element = _1
What = floor
List = [tile]
?- bagof(Element, What ^ contains(What, Element), List).
Element = _1
What = _2
List = [window,door,room,table,floor,tile,table,floor,tile,tile]
?- bagof(Element, contains(house, truck), List)
no
Standard
This predicate is part of the ISO-Prolog Standard.
See also
findall/3,
setof/3
|
