Loop of length 19 starting with a string of length 8
found after enumerating 1226656 derivations:

.b.baaabaa
	rule b -> ac at position 0
.ac.baaabaa
	rule cba -> abcb at position 1
.aabcb.aabaa
	rule cba -> abcb at position 3
.aababcb.abaa
	rule a ->  at position 3
.aabbcb.abaa
	rule cba -> abcb at position 4
.aabbabcb.baa
	rule b -> ac at position 5
.aabbaaccb.baa
	rule b -> ac at position 8
.aabbaaccac.baa
	rule a ->  at position 8
.aabbaaccc.baa
	rule cba -> abcb at position 8
.aabbaaccabcb.a
	rule a ->  at position 8
.aabbaaccbcb.a
	rule cba -> abcb at position 9
.aabbaaccbabcb.
	rule cba -> abcb at position 7
.aabbaacabcbbcb.
	rule a ->  at position 7
.aabbaacbcbbcb.
	rule b -> ac at position 10
.aabbaacbcbaccb.
	rule cba -> abcb at position 8
.aabbaacbabcbccb.
	rule cba -> abcb at position 6
.aabbaaabcbbcbccb.
	rule b -> ac at position 10
.aabbaaabcbaccbccb.
	rule cba -> abcb at position 8
.aabbaaababcbccbccb.
	rule b -> ac at position 9
.aabbaaabaaccbccbccb.