Loop of length 11 starting with a string of length 9
found after enumerating 183 derivations:

.cbb.bbbbbb
	rule cbb -> bbacc at position 0
.bbacc.bbbbbb
	rule cbb -> bbacc at position 4
.bbacbbacc.bbbb
	rule cbb -> bbacc at position 8
.bbacbbacbbacc.bb
	rule cbb -> bbacc at position 7
.bbacbbabbaccacc.bb
	rule ab -> bb at position 6
.bbacbbbbbaccacc.bb
	rule cbb -> bbacc at position 14
.bbacbbbbbaccacbbacc.
	rule cbb -> bbacc at position 13
.bbacbbbbbaccabbaccacc.
	rule ab -> bb at position 12
.bbacbbbbbaccbbbaccacc.
	rule cbb -> bbacc at position 11
.bbacbbbbbacbbaccbaccacc.
	rule cbb -> bbacc at position 10
.bbacbbbbbabbaccaccbaccacc.
	rule ab -> bb at position 9
.bbacbbbbbbbbaccaccbaccacc.