Loop of length 12 starting with a string of length 10
found after enumerating 16854 derivations:

.cbaa.aaaaaa
	rule cbaa -> aaaccb at position 0
.aaaccb.aaaaaa
	rule cbaa -> aaaccb at position 4
.aaacaaaccb.aaaa
	rule a -> b at position 4
.aaacbaaccb.aaaa
	rule cbaa -> aaaccb at position 8
.aaacbaacaaaccb.aa
	rule a -> b at position 8
.aaacbaacbaaccb.aa
	rule cbaa -> aaaccb at position 7
.aaacbaaaaaccbccb.aa
	rule cbaa -> aaaccb at position 14
.aaacbaaaaaccbcaaaccb.
	rule a -> b at position 14
.aaacbaaaaaccbcbaaccb.
	rule cbaa -> aaaccb at position 13
.aaacbaaaaaccbaaaccbccb.
	rule cbaa -> aaaccb at position 11
.aaacbaaaaacaaaccbaccbccb.
	rule a -> b at position 11
.aaacbaaaaacbaaccbaccbccb.
	rule cbaa -> aaaccb at position 10
.aaacbaaaaaaaaccbccbaccbccb.