YES After renaming modulo { a->0, c->1 }, it remains to prove termination of the 3-rule system { 0 0 0 -> 0 1 0 0 , 1 1 1 -> 0 , 0 -> } Applying sparse 2-tiling [Hofbauer/Geser/Waldmann, FSCD 2019]. After renaming modulo { (0,0)->0, (0,1)->1, (1,0)->2, (0,3)->3, (2,0)->4, (1,1)->5, (1,3)->6, (2,1)->7, (2,3)->8 }, it remains to prove termination of the 27-rule system { 0 0 0 0 -> 0 1 2 0 0 , 0 0 0 1 -> 0 1 2 0 1 , 0 0 0 3 -> 0 1 2 0 3 , 2 0 0 0 -> 2 1 2 0 0 , 2 0 0 1 -> 2 1 2 0 1 , 2 0 0 3 -> 2 1 2 0 3 , 4 0 0 0 -> 4 1 2 0 0 , 4 0 0 1 -> 4 1 2 0 1 , 4 0 0 3 -> 4 1 2 0 3 , 1 5 5 2 -> 0 0 , 1 5 5 5 -> 0 1 , 1 5 5 6 -> 0 3 , 5 5 5 2 -> 2 0 , 5 5 5 5 -> 2 1 , 5 5 5 6 -> 2 3 , 7 5 5 2 -> 4 0 , 7 5 5 5 -> 4 1 , 7 5 5 6 -> 4 3 , 0 0 -> 0 , 0 1 -> 1 , 0 3 -> 3 , 2 0 -> 2 , 2 1 -> 5 , 2 3 -> 6 , 4 0 -> 4 , 4 1 -> 7 , 4 3 -> 8 } The system was filtered by the following matrix interpretation of type E_J with J = {1,...,2} and dimension 2: 0 is interpreted by / \ | 1 6 | | 0 1 | \ / 1 is interpreted by / \ | 1 5 | | 0 1 | \ / 2 is interpreted by / \ | 1 0 | | 0 1 | \ / 3 is interpreted by / \ | 1 1 | | 0 1 | \ / 4 is interpreted by / \ | 1 0 | | 0 1 | \ / 5 is interpreted by / \ | 1 4 | | 0 1 | \ / 6 is interpreted by / \ | 1 0 | | 0 1 | \ / 7 is interpreted by / \ | 1 0 | | 0 1 | \ / 8 is interpreted by / \ | 1 0 | | 0 1 | \ / After renaming modulo { }, it remains to prove termination of the 0-rule system { } The system is trivially terminating.