YES After renaming modulo { 0->0, 1->1, 2->2 }, it remains to prove termination of the 4-rule system { 0 1 2 1 -> 1 2 1 1 0 1 2 0 1 2 , 0 1 2 1 -> 1 2 1 1 0 1 2 0 1 2 0 1 2 , 0 1 2 1 -> 1 2 1 1 0 1 2 0 1 2 0 1 2 0 1 2 , 0 1 2 1 -> 1 2 1 1 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 } Applying the dependency pairs transformation. After renaming modulo { (0,true)->0, (1,false)->1, (2,false)->2, (0,false)->3 }, it remains to prove termination of the 9-rule system { 0 1 2 1 -> 0 1 2 3 1 2 , 0 1 2 1 -> 0 1 2 , 0 1 2 1 -> 0 1 2 3 1 2 3 1 2 , 0 1 2 1 -> 0 1 2 3 1 2 3 1 2 3 1 2 , 0 1 2 1 -> 0 1 2 3 1 2 3 1 2 3 1 2 3 1 2 , 3 1 2 1 ->= 1 2 1 1 3 1 2 3 1 2 , 3 1 2 1 ->= 1 2 1 1 3 1 2 3 1 2 3 1 2 , 3 1 2 1 ->= 1 2 1 1 3 1 2 3 1 2 3 1 2 3 1 2 , 3 1 2 1 ->= 1 2 1 1 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 } The system was filtered by the following matrix interpretation of type E_J with J = {1,...,2} and dimension 5: 0 is interpreted by / \ | 1 0 1 0 0 | | 0 1 0 0 0 | | 0 0 0 0 0 | | 0 0 0 0 0 | | 0 0 0 0 0 | \ / 1 is interpreted by / \ | 1 0 0 0 0 | | 0 1 0 0 0 | | 0 0 0 1 0 | | 0 0 0 0 0 | | 0 1 0 0 1 | \ / 2 is interpreted by / \ | 1 0 0 0 0 | | 0 1 0 0 0 | | 0 0 0 0 0 | | 0 0 0 0 1 | | 0 0 0 0 0 | \ / 3 is interpreted by / \ | 1 0 0 0 0 | | 0 1 0 0 0 | | 0 1 1 0 0 | | 0 0 0 0 0 | | 0 0 1 0 0 | \ / After renaming modulo { 3->0, 1->1, 2->2 }, it remains to prove termination of the 4-rule system { 0 1 2 1 ->= 1 2 1 1 0 1 2 0 1 2 , 0 1 2 1 ->= 1 2 1 1 0 1 2 0 1 2 0 1 2 , 0 1 2 1 ->= 1 2 1 1 0 1 2 0 1 2 0 1 2 0 1 2 , 0 1 2 1 ->= 1 2 1 1 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 } The system is trivially terminating.