     (add-to-open-set) ;
 
 : ?add-to-open-set ( node astar -- )
-    2dup astar>> in-closed-set>> key? [ 2drop ] [ add-to-open-set ] if ;
+    2dup astar>> in-closed-set>> in? [ 2drop ] [ add-to-open-set ] if ;
 
 : move-to-closed-set ( node astar -- )
-    [ astar>> in-closed-set>> conjoin ] [ in-open-set>> delete-at ] 2bi ;
+    [ astar>> in-closed-set>> adjoin ] [ in-open-set>> delete-at ] 2bi ;
 
 : get-first ( astar -- node )
     [ open-set>> heap-pop drop dup ] [ move-to-closed-set ] bi ;

    astar-simple new swap >>heuristic swap >>cost swap >>neighbours ;

: considered ( astar -- considered )
    in-closed-set>> keys ;

: (init) ( from to astar -- )
    swap >>goal
    H{ } clone over astar>> (>>g)
    { } <hash-set> over astar>> (>>in-closed-set)
    H{ } clone >>origin
    H{ } clone >>in-open-set
    <min-heap> >>open-set
