Loop of length 7 starting with a string of length 3 found after enumerating 463 derivations: .ba.a rule ba -> abcaab at position 0 .abcaab.a rule a -> at position 3 .abcab.a rule a -> at position 3 .abcb.a rule ba -> abcaab at position 3 .abcabcaab. rule a -> at position 3 .abcbcaab. rule b -> at position 3 .abccaab. rule cc -> at position 2 .abaab.