YES After renaming modulo { a->0, b->1, C->2, c->3, A->4, B->5 }, it remains to prove termination of the 24-rule system { 0 1 -> 2 , 1 3 -> 4 , 3 0 -> 5 , 4 2 -> 1 , 2 5 -> 0 , 5 4 -> 3 , 0 0 0 0 -> 4 4 4 , 4 4 4 4 -> 0 0 0 , 1 1 1 1 -> 5 5 5 , 5 5 5 5 -> 1 1 1 , 3 3 3 3 -> 2 2 2 , 2 2 2 2 -> 3 3 3 , 5 0 0 0 -> 3 4 4 4 , 4 4 4 1 -> 0 0 0 2 , 2 1 1 1 -> 0 5 5 5 , 5 5 5 3 -> 1 1 1 4 , 4 3 3 3 -> 1 2 2 2 , 2 2 2 0 -> 3 3 3 5 , 0 4 -> , 4 0 -> , 1 5 -> , 5 1 -> , 3 2 -> , 2 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 1 | | 0 1 | \ / 3 is interpreted by / \ | 1 1 | | 0 1 | \ / 4 is interpreted by / \ | 1 1 | | 0 1 | \ / 5 is interpreted by / \ | 1 1 | | 0 1 | \ / After renaming modulo { 5->0, 0->1, 3->2, 4->3, 1->4, 2->5 }, it remains to prove termination of the 6-rule system { 0 1 1 1 -> 2 3 3 3 , 3 3 3 4 -> 1 1 1 5 , 5 4 4 4 -> 1 0 0 0 , 0 0 0 2 -> 4 4 4 3 , 3 2 2 2 -> 4 5 5 5 , 5 5 5 1 -> 2 2 2 0 } Applying the dependency pairs transformation. After renaming modulo { (0,true)->0, (1,false)->1, (3,true)->2, (3,false)->3, (4,false)->4, (5,true)->5, (0,false)->6, (2,false)->7, (5,false)->8 }, it remains to prove termination of the 18-rule system { 0 1 1 1 -> 2 3 3 , 0 1 1 1 -> 2 3 , 0 1 1 1 -> 2 , 2 3 3 4 -> 5 , 5 4 4 4 -> 0 6 6 , 5 4 4 4 -> 0 6 , 5 4 4 4 -> 0 , 0 6 6 7 -> 2 , 2 7 7 7 -> 5 8 8 , 2 7 7 7 -> 5 8 , 2 7 7 7 -> 5 , 5 8 8 1 -> 0 , 6 1 1 1 ->= 7 3 3 3 , 3 3 3 4 ->= 1 1 1 8 , 8 4 4 4 ->= 1 6 6 6 , 6 6 6 7 ->= 4 4 4 3 , 3 7 7 7 ->= 4 8 8 8 , 8 8 8 1 ->= 7 7 7 6 } 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 | \ / 5 is interpreted by / \ | 1 1 | | 0 1 | \ / 6 is interpreted by / \ | 1 1 | | 0 1 | \ / 7 is interpreted by / \ | 1 1 | | 0 1 | \ / 8 is interpreted by / \ | 1 1 | | 0 1 | \ / After renaming modulo { 6->0, 1->1, 7->2, 3->3, 4->4, 8->5 }, it remains to prove termination of the 6-rule system { 0 1 1 1 ->= 2 3 3 3 , 3 3 3 4 ->= 1 1 1 5 , 5 4 4 4 ->= 1 0 0 0 , 0 0 0 2 ->= 4 4 4 3 , 3 2 2 2 ->= 4 5 5 5 , 5 5 5 1 ->= 2 2 2 0 } The system is trivially terminating.