0.00/0.42 YES 0.00/0.42 0.00/0.42 0.00/0.42 Applying context closure of depth 1 in the following form: System R over Sigma 0.00/0.42 maps to { fold(xly) -> fold(xry) | l -> r in R, x,y in Sigma } over Sigma^2, 0.00/0.42 where fold(a_1,...,a_n) = (a_1,a_2)...(a_{n-1}a_{n}) 0.00/0.42 0.00/0.42 Remains to prove termination of the 54-rule system 0.00/0.42 { [b, b] [b, b] [b, b] [b, b] -> [b, c] [c, a] [a, c] [c, b] , 0.00/0.42 [b, a] [a, a] [a, c] [c, b] -> [b, a] [a, b] [b, a] [a, b] , 0.00/0.42 [b, a] [a, a] [a, c] [c, b] -> [b, c] [c, b] [b, c] [c, b] , 0.00/0.42 [b, c] [c, b] [b, b] [b, b] ->= [b, b] [b, b] [b, c] [c, b] , 0.00/0.42 [b, c] [c, c] [c, c] [c, b] ->= [b, b] [b, b] [b, c] [c, b] , 0.00/0.42 [b, a] [a, a] [a, a] [a, b] ->= [b, a] [a, b] [b, c] [c, b] , 0.00/0.42 [b, b] [b, b] [b, b] [b, c] -> [b, c] [c, a] [a, c] [c, c] , 0.00/0.42 [b, a] [a, a] [a, c] [c, c] -> [b, a] [a, b] [b, a] [a, c] , 0.00/0.42 [b, a] [a, a] [a, c] [c, c] -> [b, c] [c, b] [b, c] [c, c] , 0.00/0.42 [b, c] [c, b] [b, b] [b, c] ->= [b, b] [b, b] [b, c] [c, c] , 0.00/0.42 [b, c] [c, c] [c, c] [c, c] ->= [b, b] [b, b] [b, c] [c, c] , 0.00/0.42 [b, a] [a, a] [a, a] [a, c] ->= [b, a] [a, b] [b, c] [c, c] , 0.00/0.42 [b, b] [b, b] [b, b] [b, a] -> [b, c] [c, a] [a, c] [c, a] , 0.00/0.42 [b, a] [a, a] [a, c] [c, a] -> [b, a] [a, b] [b, a] [a, a] , 0.00/0.42 [b, a] [a, a] [a, c] [c, a] -> [b, c] [c, b] [b, c] [c, a] , 0.00/0.42 [b, c] [c, b] [b, b] [b, a] ->= [b, b] [b, b] [b, c] [c, a] , 0.00/0.42 [b, c] [c, c] [c, c] [c, a] ->= [b, b] [b, b] [b, c] [c, a] , 0.00/0.42 [b, a] [a, a] [a, a] [a, a] ->= [b, a] [a, b] [b, c] [c, a] , 0.00/0.42 [c, b] [b, b] [b, b] [b, b] -> [c, c] [c, a] [a, c] [c, b] , 0.00/0.42 [c, a] [a, a] [a, c] [c, b] -> [c, a] [a, b] [b, a] [a, b] , 0.00/0.42 [c, a] [a, a] [a, c] [c, b] -> [c, c] [c, b] [b, c] [c, b] , 0.00/0.42 [c, c] [c, b] [b, b] [b, b] ->= [c, b] [b, b] [b, c] [c, b] , 0.00/0.42 [c, c] [c, c] [c, c] [c, b] ->= [c, b] [b, b] [b, c] [c, b] , 0.00/0.42 [c, a] [a, a] [a, a] [a, b] ->= [c, a] [a, b] [b, c] [c, b] , 0.00/0.42 [c, b] [b, b] [b, b] [b, c] -> [c, c] [c, a] [a, c] [c, c] , 0.00/0.42 [c, a] [a, a] [a, c] [c, c] -> [c, a] [a, b] [b, a] [a, c] , 0.00/0.42 [c, a] [a, a] [a, c] [c, c] -> [c, c] [c, b] [b, c] [c, c] , 0.00/0.42 [c, c] [c, b] [b, b] [b, c] ->= [c, b] [b, b] [b, c] [c, c] , 0.00/0.42 [c, c] [c, c] [c, c] [c, c] ->= [c, b] [b, b] [b, c] [c, c] , 0.00/0.42 [c, a] [a, a] [a, a] [a, c] ->= [c, a] [a, b] [b, c] [c, c] , 0.00/0.42 [c, b] [b, b] [b, b] [b, a] -> [c, c] [c, a] [a, c] [c, a] , 0.00/0.42 [c, a] [a, a] [a, c] [c, a] -> [c, a] [a, b] [b, a] [a, a] , 0.00/0.42 [c, a] [a, a] [a, c] [c, a] -> [c, c] [c, b] [b, c] [c, a] , 0.00/0.42 [c, c] [c, b] [b, b] [b, a] ->= [c, b] [b, b] [b, c] [c, a] , 0.00/0.42 [c, c] [c, c] [c, c] [c, a] ->= [c, b] [b, b] [b, c] [c, a] , 0.00/0.42 [c, a] [a, a] [a, a] [a, a] ->= [c, a] [a, b] [b, c] [c, a] , 0.00/0.42 [a, b] [b, b] [b, b] [b, b] -> [a, c] [c, a] [a, c] [c, b] , 0.00/0.42 [a, a] [a, a] [a, c] [c, b] -> [a, a] [a, b] [b, a] [a, b] , 0.00/0.42 [a, a] [a, a] [a, c] [c, b] -> [a, c] [c, b] [b, c] [c, b] , 0.00/0.42 [a, c] [c, b] [b, b] [b, b] ->= [a, b] [b, b] [b, c] [c, b] , 0.00/0.42 [a, c] [c, c] [c, c] [c, b] ->= [a, b] [b, b] [b, c] [c, b] , 0.00/0.42 [a, a] [a, a] [a, a] [a, b] ->= [a, a] [a, b] [b, c] [c, b] , 0.00/0.42 [a, b] [b, b] [b, b] [b, c] -> [a, c] [c, a] [a, c] [c, c] , 0.00/0.42 [a, a] [a, a] [a, c] [c, c] -> [a, a] [a, b] [b, a] [a, c] , 0.00/0.42 [a, a] [a, a] [a, c] [c, c] -> [a, c] [c, b] [b, c] [c, c] , 0.00/0.42 [a, c] [c, b] [b, b] [b, c] ->= [a, b] [b, b] [b, c] [c, c] , 0.00/0.42 [a, c] [c, c] [c, c] [c, c] ->= [a, b] [b, b] [b, c] [c, c] , 0.00/0.42 [a, a] [a, a] [a, a] [a, c] ->= [a, a] [a, b] [b, c] [c, c] , 0.00/0.42 [a, b] [b, b] [b, b] [b, a] -> [a, c] [c, a] [a, c] [c, a] , 0.00/0.42 [a, a] [a, a] [a, c] [c, a] -> [a, a] [a, b] [b, a] [a, a] , 0.00/0.42 [a, a] [a, a] [a, c] [c, a] -> [a, c] [c, b] [b, c] [c, a] , 0.00/0.42 [a, c] [c, b] [b, b] [b, a] ->= [a, b] [b, b] [b, c] [c, a] , 0.00/0.42 [a, c] [c, c] [c, c] [c, a] ->= [a, b] [b, b] [b, c] [c, a] , 0.00/0.42 [a, a] [a, a] [a, a] [a, a] ->= [a, a] [a, b] [b, c] [c, a] } 0.00/0.42 0.00/0.42 0.00/0.42 0.00/0.42 The system was filtered by the following matrix interpretation 0.00/0.42 of type E_J with J = {1,...,2} and dimension 2: 0.00/0.42 0.00/0.42 [b, b] is interpreted by 0.00/0.42 / \ 0.00/0.42 | 1 0 | 0.00/0.42 | 0 1 | 0.00/0.42 \ / 0.00/0.42 [b, c] is interpreted by 0.00/0.42 / \ 0.00/0.42 | 1 0 | 0.00/0.42 | 0 1 | 0.00/0.42 \ / 0.00/0.42 [c, a] is interpreted by 0.00/0.42 / \ 0.00/0.42 | 1 0 | 0.00/0.42 | 0 1 | 0.00/0.42 \ / 0.00/0.42 [a, c] is interpreted by 0.00/0.42 / \ 0.00/0.42 | 1 0 | 0.00/0.42 | 0 1 | 0.00/0.42 \ / 0.00/0.42 [c, b] is interpreted by 0.00/0.42 / \ 0.00/0.42 | 1 0 | 0.00/0.42 | 0 1 | 0.00/0.42 \ / 0.00/0.42 [b, a] is interpreted by 0.00/0.42 / \ 0.00/0.42 | 1 0 | 0.00/0.42 | 0 1 | 0.00/0.42 \ / 0.00/0.42 [a, a] is interpreted by 0.00/0.42 / \ 0.00/0.42 | 1 1 | 0.00/0.42 | 0 1 | 0.00/0.42 \ / 0.00/0.42 [a, b] is interpreted by 0.00/0.42 / \ 0.00/0.42 | 1 0 | 0.00/0.42 | 0 1 | 0.00/0.42 \ / 0.00/0.42 [c, c] is interpreted by 0.00/0.42 / \ 0.00/0.42 | 1 0 | 0.00/0.42 | 0 1 | 0.00/0.42 \ / 0.00/0.42 0.00/0.42 Remains to prove termination of the 30-rule system 0.00/0.42 { [b, b] [b, b] [b, b] [b, b] -> [b, c] [c, a] [a, c] [c, b] , 0.00/0.42 [b, c] [c, b] [b, b] [b, b] ->= [b, b] [b, b] [b, c] [c, b] , 0.00/0.42 [b, c] [c, c] [c, c] [c, b] ->= [b, b] [b, b] [b, c] [c, b] , 0.00/0.42 [b, b] [b, b] [b, b] [b, c] -> [b, c] [c, a] [a, c] [c, c] , 0.00/0.42 [b, c] [c, b] [b, b] [b, c] ->= [b, b] [b, b] [b, c] [c, c] , 0.00/0.42 [b, c] [c, c] [c, c] [c, c] ->= [b, b] [b, b] [b, c] [c, c] , 0.00/0.42 [b, b] [b, b] [b, b] [b, a] -> [b, c] [c, a] [a, c] [c, a] , 0.00/0.42 [b, a] [a, a] [a, c] [c, a] -> [b, a] [a, b] [b, a] [a, a] , 0.00/0.42 [b, c] [c, b] [b, b] [b, a] ->= [b, b] [b, b] [b, c] [c, a] , 0.00/0.42 [b, c] [c, c] [c, c] [c, a] ->= [b, b] [b, b] [b, c] [c, a] , 0.00/0.42 [c, b] [b, b] [b, b] [b, b] -> [c, c] [c, a] [a, c] [c, b] , 0.00/0.42 [c, c] [c, b] [b, b] [b, b] ->= [c, b] [b, b] [b, c] [c, b] , 0.00/0.42 [c, c] [c, c] [c, c] [c, b] ->= [c, b] [b, b] [b, c] [c, b] , 0.00/0.42 [c, b] [b, b] [b, b] [b, c] -> [c, c] [c, a] [a, c] [c, c] , 0.00/0.42 [c, c] [c, b] [b, b] [b, c] ->= [c, b] [b, b] [b, c] [c, c] , 0.00/0.42 [c, c] [c, c] [c, c] [c, c] ->= [c, b] [b, b] [b, c] [c, c] , 0.00/0.42 [c, b] [b, b] [b, b] [b, a] -> [c, c] [c, a] [a, c] [c, a] , 0.00/0.42 [c, a] [a, a] [a, c] [c, a] -> [c, a] [a, b] [b, a] [a, a] , 0.00/0.42 [c, c] [c, b] [b, b] [b, a] ->= [c, b] [b, b] [b, c] [c, a] , 0.00/0.42 [c, c] [c, c] [c, c] [c, a] ->= [c, b] [b, b] [b, c] [c, a] , 0.00/0.42 [a, b] [b, b] [b, b] [b, b] -> [a, c] [c, a] [a, c] [c, b] , 0.00/0.42 [a, c] [c, b] [b, b] [b, b] ->= [a, b] [b, b] [b, c] [c, b] , 0.00/0.42 [a, c] [c, c] [c, c] [c, b] ->= [a, b] [b, b] [b, c] [c, b] , 0.00/0.42 [a, b] [b, b] [b, b] [b, c] -> [a, c] [c, a] [a, c] [c, c] , 0.00/0.42 [a, c] [c, b] [b, b] [b, c] ->= [a, b] [b, b] [b, c] [c, c] , 0.00/0.42 [a, c] [c, c] [c, c] [c, c] ->= [a, b] [b, b] [b, c] [c, c] , 0.00/0.42 [a, b] [b, b] [b, b] [b, a] -> [a, c] [c, a] [a, c] [c, a] , 0.00/0.42 [a, a] [a, a] [a, c] [c, a] -> [a, a] [a, b] [b, a] [a, a] , 0.00/0.42 [a, c] [c, b] [b, b] [b, a] ->= [a, b] [b, b] [b, c] [c, a] , 0.00/0.42 [a, c] [c, c] [c, c] [c, a] ->= [a, b] [b, b] [b, c] [c, a] } 0.00/0.42 0.00/0.42 0.00/0.42 The system was filtered by the following matrix interpretation 0.00/0.42 of type E_J with J = {1,...,2} and dimension 2: 0.00/0.42 0.00/0.42 [b, b] is interpreted by 0.00/0.42 / \ 0.00/0.42 | 1 2 | 0.00/0.42 | 0 1 | 0.00/0.42 \ / 0.00/0.42 [b, c] is interpreted by 0.00/0.42 / \ 0.00/0.42 | 1 2 | 0.00/0.42 | 0 1 | 0.00/0.42 \ / 0.00/0.42 [c, a] is interpreted by 0.00/0.42 / \ 0.00/0.42 | 1 1 | 0.00/0.42 | 0 1 | 0.00/0.42 \ / 0.00/0.42 [a, c] is interpreted by 0.00/0.42 / \ 0.00/0.42 | 1 0 | 0.00/0.42 | 0 1 | 0.00/0.42 \ / 0.00/0.42 [c, b] is interpreted by 0.00/0.42 / \ 0.00/0.42 | 1 3 | 0.00/0.42 | 0 1 | 0.00/0.42 \ / 0.00/0.42 [b, a] is interpreted by 0.00/0.42 / \ 0.00/0.42 | 1 0 | 0.00/0.42 | 0 1 | 0.00/0.42 \ / 0.00/0.42 [a, a] is interpreted by 0.00/0.42 / \ 0.00/0.42 | 1 0 | 0.00/0.42 | 0 1 | 0.00/0.42 \ / 0.00/0.42 [a, b] is interpreted by 0.00/0.42 / \ 0.00/0.42 | 1 0 | 0.00/0.42 | 0 1 | 0.00/0.42 \ / 0.00/0.42 [c, c] is interpreted by 0.00/0.42 / \ 0.00/0.42 | 1 3 | 0.00/0.42 | 0 1 | 0.00/0.42 \ / 0.00/0.42 0.00/0.42 Remains to prove termination of the 9-rule system 0.00/0.42 { [b, c] [c, b] [b, b] [b, b] ->= [b, b] [b, b] [b, c] [c, b] , 0.00/0.42 [b, c] [c, b] [b, b] [b, c] ->= [b, b] [b, b] [b, c] [c, c] , 0.00/0.42 [b, c] [c, b] [b, b] [b, a] ->= [b, b] [b, b] [b, c] [c, a] , 0.00/0.42 [c, c] [c, b] [b, b] [b, b] ->= [c, b] [b, b] [b, c] [c, b] , 0.00/0.42 [c, c] [c, b] [b, b] [b, c] ->= [c, b] [b, b] [b, c] [c, c] , 0.00/0.42 [c, c] [c, b] [b, b] [b, a] ->= [c, b] [b, b] [b, c] [c, a] , 0.00/0.42 [a, c] [c, b] [b, b] [b, b] ->= [a, b] [b, b] [b, c] [c, b] , 0.00/0.42 [a, c] [c, b] [b, b] [b, c] ->= [a, b] [b, b] [b, c] [c, c] , 0.00/0.42 [a, c] [c, b] [b, b] [b, a] ->= [a, b] [b, b] [b, c] [c, a] } 0.00/0.42 0.00/0.42 0.00/0.42 The system is trivially terminating. 0.00/0.45 EOF