1.86/0.67 NO 1.95/0.69 1.95/0.69 1.95/0.69 The system was reversed. 1.95/0.69 1.95/0.69 Remains to prove termination of the 4-rule system 1.95/0.69 { a -> , 1.95/0.69 b a -> a b c a b , 1.95/0.69 b -> , 1.95/0.69 c c -> } 1.95/0.69 1.95/0.69 1.95/0.69 Loop of length 12 starting with a string of length 6 using right expansion 1.95/0.69 and the encoding {a=a, b=b, c=c}: 1.95/0.69 1.95/0.69 .ba.aaca 1.95/0.69 rule ba -> abcab at position 0 1.95/0.69 .abcab.aaca 1.95/0.69 rule a -> at position 3 1.95/0.69 .abcb.aaca 1.95/0.69 rule ba -> abcab at position 3 1.95/0.69 .abcabcab.aca 1.95/0.69 rule a -> at position 3 1.95/0.69 .abcbcab.aca 1.95/0.69 rule b -> at position 3 1.95/0.69 .abccab.aca 1.95/0.69 rule cc -> at position 2 1.95/0.69 .abab.aca 1.95/0.69 rule ba -> abcab at position 3 1.95/0.69 .abaabcab.ca 1.95/0.69 rule a -> at position 6 1.95/0.69 .abaabcb.ca 1.95/0.69 rule b -> at position 6 1.95/0.69 .abaabc.ca 1.95/0.69 rule cc -> at position 5 1.95/0.69 .abaab.a 1.95/0.69 rule ba -> abcab at position 4 1.95/0.69 .abaaabcab. 1.95/0.69 rule b -> at position 5 1.95/0.69 .abaaacab. 2.13/0.77 EOF