Post, H.

algorithm heuristic search bidirectional process lemma node v length search space value estimate network inequality section space proof function distance version destination path p post-phase heuristic estimate algorithm 2 label origin research bidirectional search algorithm phase paper property graph lemma 1 ~ ~ bidirectional search experiment relation dijkstra journal bidirectional algorithm ~ ~ ~ table result predecessor instance european path problem variable figure postprocessing candidate consistency cand-found heuristic estimates problem european journal article ðu v þ line 13 termination state algorithm 1 method ã ð t v 2 m p þ þ intelligence lines 13 press point l p l lemma 2 b bidirectional version v 2 v road networks correctness g ðv þ search processes definition meeting point