YES After renaming modulo { a->0, l->1, c->2, r->3 }, it remains to prove termination of the 4-rule system { 0 1 -> 1 0 , 0 2 -> 2 0 , 2 0 3 -> 3 0 , 1 3 0 -> 0 1 2 2 3 } The system was reversed. After renaming modulo { 1->0, 0->1, 2->2, 3->3 }, it remains to prove termination of the 4-rule system { 0 1 -> 1 0 , 2 1 -> 1 2 , 3 1 2 -> 1 3 , 1 3 0 -> 3 2 2 0 1 } Applying the dependency pairs transformation. After renaming modulo { (0,true)->0, (1,false)->1, (1,true)->2, (0,false)->3, (2,true)->4, (2,false)->5, (3,true)->6, (3,false)->7 }, it remains to prove termination of the 15-rule system { 0 1 -> 2 3 , 0 1 -> 0 , 4 1 -> 2 5 , 4 1 -> 4 , 6 1 5 -> 2 7 , 6 1 5 -> 6 , 2 7 3 -> 6 5 5 3 1 , 2 7 3 -> 4 5 3 1 , 2 7 3 -> 4 3 1 , 2 7 3 -> 0 1 , 2 7 3 -> 2 , 3 1 ->= 1 3 , 5 1 ->= 1 5 , 7 1 5 ->= 1 7 , 1 7 3 ->= 7 5 5 3 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 0 | | 0 1 | \ / 1 is interpreted by / \ | 1 1 | | 0 1 | \ / 2 is interpreted by / \ | 1 0 | | 0 1 | \ / 3 is interpreted by / \ | 1 0 | | 0 1 | \ / 4 is interpreted by / \ | 1 0 | | 0 1 | \ / 5 is interpreted by / \ | 1 0 | | 0 1 | \ / 6 is interpreted by / \ | 1 1 | | 0 1 | \ / 7 is interpreted by / \ | 1 2 | | 0 1 | \ / After renaming modulo { 6->0, 1->1, 5->2, 2->3, 7->4, 3->5 }, it remains to prove termination of the 6-rule system { 0 1 2 -> 3 4 , 3 4 5 -> 0 2 2 5 1 , 5 1 ->= 1 5 , 2 1 ->= 1 2 , 4 1 2 ->= 1 4 , 1 4 5 ->= 4 2 2 5 1 } The system was filtered by the following matrix interpretation of type E_J with J = {1,...,2} and dimension 7: 0 is interpreted by / \ | 1 0 0 0 1 0 0 | | 0 1 0 0 0 0 0 | | 0 0 0 0 0 0 0 | | 0 0 0 0 0 0 0 | | 0 0 0 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 0 | | 0 1 0 0 0 0 0 | | 0 0 0 0 0 0 0 | | 0 0 0 0 0 0 0 | | 0 0 0 0 0 1 0 | | 0 0 0 0 0 0 0 | | 0 0 0 1 0 0 0 | \ / 2 is interpreted by / \ | 1 0 0 0 0 0 0 | | 0 1 0 0 0 0 0 | | 0 0 0 0 0 0 0 | | 0 0 0 0 0 0 0 | | 0 0 0 0 0 0 1 | | 0 0 0 1 0 0 0 | | 0 0 0 0 0 0 0 | \ / 3 is interpreted by / \ | 1 0 1 0 0 0 0 | | 0 1 0 0 0 0 0 | | 0 0 0 0 0 0 0 | | 0 0 0 0 0 0 0 | | 0 0 0 0 0 0 0 | | 0 0 0 0 0 0 0 | | 0 0 0 0 0 0 0 | \ / 4 is interpreted by / \ | 1 0 0 0 0 0 0 | | 0 1 0 0 0 0 0 | | 0 0 0 1 0 0 0 | | 0 0 0 0 0 0 0 | | 0 0 0 0 0 0 0 | | 0 0 0 0 0 0 0 | | 0 0 0 0 0 0 0 | \ / 5 is interpreted by / \ | 1 0 0 0 0 0 0 | | 0 1 0 0 0 0 0 | | 0 0 0 0 0 0 0 | | 0 1 0 0 0 0 0 | | 0 0 0 0 0 0 0 | | 0 0 0 0 0 0 0 | | 0 1 0 0 0 0 0 | \ / After renaming modulo { 0->0, 1->1, 2->2, 3->3, 4->4, 5->5 }, it remains to prove termination of the 5-rule system { 0 1 2 -> 3 4 , 5 1 ->= 1 5 , 2 1 ->= 1 2 , 4 1 2 ->= 1 4 , 1 4 5 ->= 4 2 2 5 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 0 | | 0 1 | \ / 3 is interpreted by / \ | 1 0 | | 0 1 | \ / 4 is interpreted by / \ | 1 0 | | 0 1 | \ / 5 is interpreted by / \ | 1 1 | | 0 1 | \ / After renaming modulo { 5->0, 1->1, 2->2, 4->3 }, it remains to prove termination of the 4-rule system { 0 1 ->= 1 0 , 2 1 ->= 1 2 , 3 1 2 ->= 1 3 , 1 3 0 ->= 3 2 2 0 1 } The system is trivially terminating.