Graph
(node-contains? set node formula)
true iff the node node contains the formula formula. set represents the set of all terms.
Example : (node-contains? set A '(diamond p))
(node-contains-pattern? set node formula-pattern)
true iff the node node contains a formula that matches with the pattern formula-pattern.
Example : (node-contains-pattern? set A '(diamond B))
(linked? set node1 relation node2)
true iff the node node1 is linked to the node node2 by the relation relation.
Example : (linked? set A rel1 B)
(worldsformulasincluded? set world1 world2)
returns true iff the set of formulas in the world world1 is included into the set of formulas in the world world2
(sameformulas? set world1 world2)
returns true iff the set of formulas in the world world1 is equal into the set of formulas in the world world2