+rels *encode_rel(sokoban_screen *screen);
+
+int test_trans(state *s, trans_t *t);
+
+state *encode_goal(sokoban_screen *screen);
+
+int check_goal(BDD s, BDD g, BDDSET vars);
+
+int check_visited(BDD s, BDD v, BDDSET vars);
+
+lurd_t *lappend(lurd_t *l, char c);
+
+state_t *explstate(state *init, rels *rls, state *g);