YES After renaming modulo { a->0, d->1, c->2, b->3 }, it remains to prove termination of the 6-rule system { 0 0 -> 1 2 , 0 3 -> 2 2 2 , 3 3 -> 0 2 2 , 2 2 -> 3 , 2 1 -> 0 0 , 1 1 -> 3 0 2 } 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 15 | | 0 1 | \ / 1 is interpreted by / \ | 1 21 | | 0 1 | \ / 2 is interpreted by / \ | 1 9 | | 0 1 | \ / 3 is interpreted by / \ | 1 17 | | 0 1 | \ / After renaming modulo { 0->0, 1->1, 2->2 }, it remains to prove termination of the 2-rule system { 0 0 -> 1 2 , 2 1 -> 0 0 } The system was reversed. After renaming modulo { 0->0, 2->1, 1->2 }, it remains to prove termination of the 2-rule system { 0 0 -> 1 2 , 2 1 -> 0 0 } Applying the dependency pairs transformation. After renaming modulo { (0,true)->0, (0,false)->1, (2,true)->2, (1,false)->3, (2,false)->4 }, it remains to prove termination of the 5-rule system { 0 1 -> 2 , 2 3 -> 0 1 , 2 3 -> 0 , 1 1 ->= 3 4 , 4 3 ->= 1 1 } 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 1 | | 0 1 | \ / 1 is interpreted by / \ | 1 1 | | 0 1 | \ / 2 is interpreted by / \ | 1 1 | | 0 1 | \ / 3 is interpreted by / \ | 1 1 | | 0 1 | \ / 4 is interpreted by / \ | 1 1 | | 0 1 | \ / After renaming modulo { 2->0, 3->1, 0->2, 1->3, 4->4 }, it remains to prove termination of the 3-rule system { 0 1 -> 2 3 , 3 3 ->= 1 4 , 4 1 ->= 3 3 } 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 1 | | 0 1 | \ / 1 is interpreted by / \ | 1 1 | | 0 1 | \ / 2 is interpreted by / \ | 1 0 | | 0 1 | \ / 3 is interpreted by / \ | 1 1 | | 0 1 | \ / 4 is interpreted by / \ | 1 1 | | 0 1 | \ / After renaming modulo { 3->0, 1->1, 4->2 }, it remains to prove termination of the 2-rule system { 0 0 ->= 1 2 , 2 1 ->= 0 0 } The system is trivially terminating.