We prove that two pushing-blocks puzzles are intractable in 2D. One of our constructions improves an earlier result that established intractability in 3D [OS99] for a puzzle inspired by the game PushPush. The second construction answers a question we raised in [DDO00] for a variant we call Push-1. Both puzzles consist of unit square blocks on an integer lattice; all blocks are movable. An agent...

christian zionism, as an extremist christian movement, based on certain literal interpretations of the holy scripture, tend to materialize its deterministic prophetical beliefs so that to provide the ground for the reappearance of the christ at the end of the world. on the basis of this, the movement believes that men ought to pass seven phases or destinies which will lead to the reappearance o...

We prove that two pushing-blocks puzzles are intractable in 2D. One of our constructions improves an earlier result that established intractability in 3D [OS99] for a puzzle inspired by the game PushPush. The second construction answers a question we raised in [DDO00] for a variant we call Push-1. Both puzzles consist of unit square blocks on an integer lattice; all blocks are movable. An agent...