16
Definability of Types
•
Definition
. Let A
2
STRUCT[
s
], and
a
2
A.
The FO
k
type of (A,
a
) is:
tp
FO
k
(A,
a
) = {
f
(
x
)
2
FO
k
| A
²
f
(
a
) }
•
•
One could define L
w
1
,
w
types as well, but they
turn out to be the same as FO
k
types
[ why
?? ]