YES After renaming modulo { a->0, b->1, c->2 }, it remains to prove termination of the 4-rule system { 0 -> , 0 1 -> 1 1 0 2 , 1 1 -> 0 , 2 2 -> } The system was reversed. After renaming modulo { 0->0, 1->1, 2->2 }, it remains to prove termination of the 4-rule system { 0 -> , 1 0 -> 2 0 1 1 , 1 1 -> 0 , 2 2 -> } Applying sparse 2-tiling [Hofbauer/Geser/Waldmann, FSCD 2019]. After renaming modulo { (0,0)->0, (0,1)->1, (0,2)->2, (0,4)->3, (1,0)->4, (1,1)->5, (1,2)->6, (1,4)->7, (2,0)->8, (2,1)->9, (2,2)->10, (2,4)->11, (3,0)->12, (3,1)->13, (3,2)->14, (3,4)->15 }, it remains to prove termination of the 64-rule system { 0 0 -> 0 , 0 1 -> 1 , 0 2 -> 2 , 0 3 -> 3 , 4 0 -> 4 , 4 1 -> 5 , 4 2 -> 6 , 4 3 -> 7 , 8 0 -> 8 , 8 1 -> 9 , 8 2 -> 10 , 8 3 -> 11 , 12 0 -> 12 , 12 1 -> 13 , 12 2 -> 14 , 12 3 -> 15 , 1 4 0 -> 2 8 1 5 4 , 1 4 1 -> 2 8 1 5 5 , 1 4 2 -> 2 8 1 5 6 , 1 4 3 -> 2 8 1 5 7 , 5 4 0 -> 6 8 1 5 4 , 5 4 1 -> 6 8 1 5 5 , 5 4 2 -> 6 8 1 5 6 , 5 4 3 -> 6 8 1 5 7 , 9 4 0 -> 10 8 1 5 4 , 9 4 1 -> 10 8 1 5 5 , 9 4 2 -> 10 8 1 5 6 , 9 4 3 -> 10 8 1 5 7 , 13 4 0 -> 14 8 1 5 4 , 13 4 1 -> 14 8 1 5 5 , 13 4 2 -> 14 8 1 5 6 , 13 4 3 -> 14 8 1 5 7 , 1 5 4 -> 0 0 , 1 5 5 -> 0 1 , 1 5 6 -> 0 2 , 1 5 7 -> 0 3 , 5 5 4 -> 4 0 , 5 5 5 -> 4 1 , 5 5 6 -> 4 2 , 5 5 7 -> 4 3 , 9 5 4 -> 8 0 , 9 5 5 -> 8 1 , 9 5 6 -> 8 2 , 9 5 7 -> 8 3 , 13 5 4 -> 12 0 , 13 5 5 -> 12 1 , 13 5 6 -> 12 2 , 13 5 7 -> 12 3 , 2 10 8 -> 0 , 2 10 9 -> 1 , 2 10 10 -> 2 , 2 10 11 -> 3 , 6 10 8 -> 4 , 6 10 9 -> 5 , 6 10 10 -> 6 , 6 10 11 -> 7 , 10 10 8 -> 8 , 10 10 9 -> 9 , 10 10 10 -> 10 , 10 10 11 -> 11 , 14 10 8 -> 12 , 14 10 9 -> 13 , 14 10 10 -> 14 , 14 10 11 -> 15 } 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 4 | | 0 1 | \ / 1 is interpreted by / \ | 1 2 | | 0 1 | \ / 2 is interpreted by / \ | 1 1 | | 0 1 | \ / 3 is interpreted by / \ | 1 0 | | 0 1 | \ / 4 is interpreted by / \ | 1 4 | | 0 1 | \ / 5 is interpreted by / \ | 1 2 | | 0 1 | \ / 6 is interpreted by / \ | 1 1 | | 0 1 | \ / 7 is interpreted by / \ | 1 0 | | 0 1 | \ / 8 is interpreted by / \ | 1 1 | | 0 1 | \ / 9 is interpreted by / \ | 1 3 | | 0 1 | \ / 10 is interpreted by / \ | 1 2 | | 0 1 | \ / 11 is interpreted by / \ | 1 0 | | 0 1 | \ / 12 is interpreted by / \ | 1 2 | | 0 1 | \ / 13 is interpreted by / \ | 1 2 | | 0 1 | \ / 14 is interpreted by / \ | 1 0 | | 0 1 | \ / 15 is interpreted by / \ | 1 0 | | 0 1 | \ / After renaming modulo { 8->0, 1->1, 9->2, 2->3, 10->4, 4->5, 0->6, 5->7, 6->8, 3->9, 7->10 }, it remains to prove termination of the 24-rule system { 0 1 -> 2 , 0 3 -> 4 , 1 5 6 -> 3 0 1 7 5 , 1 5 1 -> 3 0 1 7 7 , 1 5 3 -> 3 0 1 7 8 , 1 5 9 -> 3 0 1 7 10 , 7 5 6 -> 8 0 1 7 5 , 7 5 1 -> 8 0 1 7 7 , 7 5 3 -> 8 0 1 7 8 , 7 5 9 -> 8 0 1 7 10 , 2 5 6 -> 4 0 1 7 5 , 2 5 1 -> 4 0 1 7 7 , 2 5 3 -> 4 0 1 7 8 , 2 5 9 -> 4 0 1 7 10 , 1 7 5 -> 6 6 , 1 7 7 -> 6 1 , 1 7 8 -> 6 3 , 1 7 10 -> 6 9 , 7 7 5 -> 5 6 , 7 7 7 -> 5 1 , 7 7 8 -> 5 3 , 7 7 10 -> 5 9 , 3 4 0 -> 6 , 8 4 0 -> 5 } Applying the dependency pairs transformation. After renaming modulo { (0,true)->0, (1,false)->1, (2,true)->2, (1,true)->3, (5,false)->4, (6,false)->5, (3,true)->6, (0,false)->7, (7,false)->8, (7,true)->9, (3,false)->10, (8,false)->11, (8,true)->12, (9,false)->13, (10,false)->14, (2,false)->15, (4,false)->16 }, it remains to prove termination of the 79-rule system { 0 1 -> 2 , 3 4 5 -> 6 7 1 8 4 , 3 4 5 -> 0 1 8 4 , 3 4 5 -> 3 8 4 , 3 4 5 -> 9 4 , 3 4 1 -> 6 7 1 8 8 , 3 4 1 -> 0 1 8 8 , 3 4 1 -> 3 8 8 , 3 4 1 -> 9 8 , 3 4 1 -> 9 , 3 4 10 -> 6 7 1 8 11 , 3 4 10 -> 0 1 8 11 , 3 4 10 -> 3 8 11 , 3 4 10 -> 9 11 , 3 4 10 -> 12 , 3 4 13 -> 6 7 1 8 14 , 3 4 13 -> 0 1 8 14 , 3 4 13 -> 3 8 14 , 3 4 13 -> 9 14 , 9 4 5 -> 12 7 1 8 4 , 9 4 5 -> 0 1 8 4 , 9 4 5 -> 3 8 4 , 9 4 5 -> 9 4 , 9 4 1 -> 12 7 1 8 8 , 9 4 1 -> 0 1 8 8 , 9 4 1 -> 3 8 8 , 9 4 1 -> 9 8 , 9 4 1 -> 9 , 9 4 10 -> 12 7 1 8 11 , 9 4 10 -> 0 1 8 11 , 9 4 10 -> 3 8 11 , 9 4 10 -> 9 11 , 9 4 10 -> 12 , 9 4 13 -> 12 7 1 8 14 , 9 4 13 -> 0 1 8 14 , 9 4 13 -> 3 8 14 , 9 4 13 -> 9 14 , 2 4 5 -> 0 1 8 4 , 2 4 5 -> 3 8 4 , 2 4 5 -> 9 4 , 2 4 1 -> 0 1 8 8 , 2 4 1 -> 3 8 8 , 2 4 1 -> 9 8 , 2 4 1 -> 9 , 2 4 10 -> 0 1 8 11 , 2 4 10 -> 3 8 11 , 2 4 10 -> 9 11 , 2 4 10 -> 12 , 2 4 13 -> 0 1 8 14 , 2 4 13 -> 3 8 14 , 2 4 13 -> 9 14 , 3 8 8 -> 3 , 3 8 11 -> 6 , 9 8 8 -> 3 , 9 8 11 -> 6 , 7 1 ->= 15 , 7 10 ->= 16 , 1 4 5 ->= 10 7 1 8 4 , 1 4 1 ->= 10 7 1 8 8 , 1 4 10 ->= 10 7 1 8 11 , 1 4 13 ->= 10 7 1 8 14 , 8 4 5 ->= 11 7 1 8 4 , 8 4 1 ->= 11 7 1 8 8 , 8 4 10 ->= 11 7 1 8 11 , 8 4 13 ->= 11 7 1 8 14 , 15 4 5 ->= 16 7 1 8 4 , 15 4 1 ->= 16 7 1 8 8 , 15 4 10 ->= 16 7 1 8 11 , 15 4 13 ->= 16 7 1 8 14 , 1 8 4 ->= 5 5 , 1 8 8 ->= 5 1 , 1 8 11 ->= 5 10 , 1 8 14 ->= 5 13 , 8 8 4 ->= 4 5 , 8 8 8 ->= 4 1 , 8 8 11 ->= 4 10 , 8 8 14 ->= 4 13 , 10 16 7 ->= 5 , 11 16 7 ->= 4 } 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 0 | | 0 1 | \ / 1 is interpreted by / \ | 1 2 | | 0 1 | \ / 2 is interpreted by / \ | 1 1 | | 0 1 | \ / 3 is interpreted by / \ | 1 1 | | 0 1 | \ / 4 is interpreted by / \ | 1 4 | | 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 2 | | 0 1 | \ / 9 is interpreted by / \ | 1 1 | | 0 1 | \ / 10 is interpreted by / \ | 1 2 | | 0 1 | \ / 11 is interpreted by / \ | 1 2 | | 0 1 | \ / 12 is interpreted by / \ | 1 0 | | 0 1 | \ / 13 is interpreted by / \ | 1 0 | | 0 1 | \ / 14 is interpreted by / \ | 1 0 | | 0 1 | \ / 15 is interpreted by / \ | 1 2 | | 0 1 | \ / 16 is interpreted by / \ | 1 2 | | 0 1 | \ / After renaming modulo { 7->0, 1->1, 15->2, 10->3, 16->4, 4->5, 5->6, 8->7, 11->8, 13->9, 14->10 }, it remains to prove termination of the 24-rule system { 0 1 ->= 2 , 0 3 ->= 4 , 1 5 6 ->= 3 0 1 7 5 , 1 5 1 ->= 3 0 1 7 7 , 1 5 3 ->= 3 0 1 7 8 , 1 5 9 ->= 3 0 1 7 10 , 7 5 6 ->= 8 0 1 7 5 , 7 5 1 ->= 8 0 1 7 7 , 7 5 3 ->= 8 0 1 7 8 , 7 5 9 ->= 8 0 1 7 10 , 2 5 6 ->= 4 0 1 7 5 , 2 5 1 ->= 4 0 1 7 7 , 2 5 3 ->= 4 0 1 7 8 , 2 5 9 ->= 4 0 1 7 10 , 1 7 5 ->= 6 6 , 1 7 7 ->= 6 1 , 1 7 8 ->= 6 3 , 1 7 10 ->= 6 9 , 7 7 5 ->= 5 6 , 7 7 7 ->= 5 1 , 7 7 8 ->= 5 3 , 7 7 10 ->= 5 9 , 3 4 0 ->= 6 , 8 4 0 ->= 5 } The system is trivially terminating.