In[]:=
ru23=Rule@@@Tuples[{StringTuples["AB",2],StringTuples["AB",3]}]
Out[]=
{AAAAA,AAAAB,AAABA,AAABB,AABAA,AABAB,AABBA,AABBB,ABAAA,ABAAB,ABABA,ABABB,ABBAA,ABBAB,ABBBA,ABBBB,BAAAA,BAAAB,BAABA,BAABB,BABAA,BABAB,BABBA,BABBB,BBAAA,BBAAB,BBABA,BBABB,BBBAA,BBBAB,BBBBA,BBBBB}
In[]:=
ru21=Rule@@@Tuples[{StringTuples["AB",2],StringTuples["AB",1]}]
Out[]=
{AAA,AAB,ABA,ABB,BAA,BAB,BBA,BBB}
In[]:=
Tuples[{%27,%28}]
Out[]=
In[]:=
ResourceFunction["InteractiveListSelector"][ParallelMapMonitored[MultiwaySystem[#,{"ABA"},4,"StatesGraph"]#&,%29]]
Out[]=