Loop of length 6 starting with a string of length 8
found after enumerating 45 derivations:

.bb.aabaab
	rule bb -> aba at position 0
.aba.aabaab
	rule aaa -> bb at position 2
.abbb.baab
	rule bb -> aba at position 3
.abbaba.aab
	rule aaa -> bb at position 5
.abbabbb.b
	rule bb -> aba at position 4
.abbaabab.b
	rule bb -> aba at position 7
.abbaabaaba.