YES After renaming modulo { a->0, b->1, c->2 }, it remains to prove termination of the 3-rule system { 0 0 -> 1 1 1 , 1 1 -> 2 2 2 , 2 2 2 2 -> 0 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 26 | | 0 1 | \ / 1 is interpreted by / \ | 1 17 | | 0 1 | \ / 2 is interpreted by / \ | 1 11 | | 0 1 | \ / After renaming modulo { }, it remains to prove termination of the 0-rule system { } The system is trivially terminating.