16
Games for
9
MSO
•
The l,k-Fagin game on two structures
A
,
B
:
•
•
Spoiler selects l subsets U
1
, …, U
l
of A
•
Duplicator replies with L subsets V
1
, …, V
l
of B
•
Then they play an Ehrenfeucht-Fraisse
game on (
A
, U
1
, …, U
l
) and (
B
, V
l
, …, V
l
)