22
MSO and TrCl
•
Theorem
On strings, MSO = TrCl
1
•
•
However, TrCl
2
can express a
n
.b
n
[
how ? ]
•
•
Question: what is the relationship between these
languages:
•
MSO on arbitrary graphs and TrCl
1
•
MSO on arbitrary graphs and TrCl