Loop of length 12 starting with a string of length 6
found after enumerating 14222 derivations:

.ba.aaca
	rule ba -> abcab at position 0
.abcab.aaca
	rule a ->  at position 3
.abcb.aaca
	rule ba -> abcab at position 3
.abcabcab.aca
	rule a ->  at position 3
.abcbcab.aca
	rule b ->  at position 3
.abccab.aca
	rule cc ->  at position 2
.abab.aca
	rule ba -> abcab at position 3
.abaabcab.ca
	rule a ->  at position 6
.abaabcb.ca
	rule b ->  at position 6
.abaabc.ca
	rule cc ->  at position 5
.abaab.a
	rule ba -> abcab at position 4
.abaaabcab.
	rule b ->  at position 5
.abaaacab.