Loop of length 22 starting with a string of length 10
found after enumerating 403 derivations:

.abbb.bbbbbb
	rule abbb -> bbbaaaab at position 0
.bbbaaaab.bbbbbb
	rule abbb -> bbbaaaab at position 6
.bbbaaabbbaaaab.bbbb
	rule abbb -> bbbaaaab at position 12
.bbbaaabbbaaabbbaaaab.bb
	rule abbb -> bbbaaaab at position 11
.bbbaaabbbaabbbaaaabaaaab.bb
	rule abbb -> bbbaaaab at position 10
.bbbaaabbbabbbaaaabaaaabaaaab.bb
	rule abbb -> bbbaaaab at position 9
.bbbaaabbbbbbaaaabaaaabaaaabaaaab.bb
	rule abbb -> bbbaaaab at position 30
.bbbaaabbbbbbaaaabaaaabaaaabaaabbbaaaab.
	rule abbb -> bbbaaaab at position 29
.bbbaaabbbbbbaaaabaaaabaaaabaabbbaaaabaaaab.
	rule abbb -> bbbaaaab at position 28
.bbbaaabbbbbbaaaabaaaabaaaababbbaaaabaaaabaaaab.
	rule abbb -> bbbaaaab at position 27
.bbbaaabbbbbbaaaabaaaabaaaabbbbaaaabaaaabaaaabaaaab.
	rule abbb -> bbbaaaab at position 25
.bbbaaabbbbbbaaaabaaaabaaabbbaaaabbaaaabaaaabaaaabaaaab.
	rule abbb -> bbbaaaab at position 24
.bbbaaabbbbbbaaaabaaaabaabbbaaaabaaaabbaaaabaaaabaaaabaaaab.
	rule abbb -> bbbaaaab at position 23
.bbbaaabbbbbbaaaabaaaababbbaaaabaaaabaaaabbaaaabaaaabaaaabaaaab.
	rule abbb -> bbbaaaab at position 22
.bbbaaabbbbbbaaaabaaaabbbbaaaabaaaabaaaabaaaabbaaaabaaaabaaaabaaaab.
	rule abbb -> bbbaaaab at position 20
.bbbaaabbbbbbaaaabaaabbbaaaabbaaaabaaaabaaaabaaaabbaaaabaaaabaaaabaaaab.
	rule abbb -> bbbaaaab at position 19
.bbbaaabbbbbbaaaabaabbbaaaabaaaabbaaaabaaaabaaaabaaaabbaaaabaaaabaaaabaaaab.
	rule abbb -> bbbaaaab at position 18
.bbbaaabbbbbbaaaababbbaaaabaaaabaaaabbaaaabaaaabaaaabaaaabbaaaabaaaabaaaabaaaab.
	rule abbb -> bbbaaaab at position 17
.bbbaaabbbbbbaaaabbbbaaaabaaaabaaaabaaaabbaaaabaaaabaaaabaaaabbaaaabaaaabaaaabaaaab.
	rule abbb -> bbbaaaab at position 15
.bbbaaabbbbbbaaabbbaaaabbaaaabaaaabaaaabaaaabbaaaabaaaabaaaabaaaabbaaaabaaaabaaaabaaaab.
	rule abbb -> bbbaaaab at position 14
.bbbaaabbbbbbaabbbaaaabaaaabbaaaabaaaabaaaabaaaabbaaaabaaaabaaaabaaaabbaaaabaaaabaaaabaaaab.
	rule abbb -> bbbaaaab at position 13
.bbbaaabbbbbbabbbaaaabaaaabaaaabbaaaabaaaabaaaabaaaabbaaaabaaaabaaaabaaaabbaaaabaaaabaaaabaaaab.
	rule abbb -> bbbaaaab at position 12
.bbbaaabbbbbbbbbaaaabaaaabaaaabaaaabbaaaabaaaabaaaabaaaabbaaaabaaaabaaaabaaaabbaaaabaaaabaaaabaaaab.