Loop of length 18 starting with a string of length 10
found after enumerating 26823 derivations:

.cabb.bbbbbb
	rule cabb -> aabcca at position 0
.aabcca.bbbbbb
	rule cabb -> aabcca at position 4
.aabcaabcca.bbbb
	rule a -> b at position 5
.aabcabbcca.bbbb
	rule cabb -> aabcca at position 8
.aabcabbcaabcca.bb
	rule a -> b at position 9
.aabcabbcabbcca.bb
	rule cabb -> aabcca at position 7
.aabcabbaabccacca.bb
	rule a -> b at position 7
.aabcabbbabccacca.bb
	rule a -> b at position 8
.aabcabbbbbccacca.bb
	rule cabb -> aabcca at position 14
.aabcabbbbbccacaabcca.
	rule a -> b at position 15
.aabcabbbbbccacabbcca.
	rule cabb -> aabcca at position 13
.aabcabbbbbccaaabccacca.
	rule a -> b at position 13
.aabcabbbbbccababccacca.
	rule a -> b at position 14
.aabcabbbbbccabbbccacca.
	rule cabb -> aabcca at position 11
.aabcabbbbbcaabccabccacca.
	rule a -> b at position 12
.aabcabbbbbcabbccabccacca.
	rule cabb -> aabcca at position 10
.aabcabbbbbaabccaccabccacca.
	rule a -> b at position 10
.aabcabbbbbbabccaccabccacca.
	rule a -> b at position 11
.aabcabbbbbbbbccaccabccacca.