Loop of length 10 starting with a string of length 4
found after enumerating 356 derivations:

.ab.bb
	rule ab -> bbacca at position 0
.bbacca.bb
	rule ab -> bbacca at position 5
.bbaccbbacca.b
	rule cb ->  at position 4
.bbacbacca.b
	rule cb ->  at position 3
.bbaacca.b
	rule ab -> bbacca at position 6
.bbaaccbbacca.
	rule cb ->  at position 5
.bbaacbacca.
	rule cb ->  at position 4
.bbaaacca.
	rule a -> b at position 4
.bbaabcca.
	rule ab -> bbacca at position 3
.bbabbaccacca.
	rule a -> b at position 5
.bbabbbccacca.