[FOM] criteria for the existence of infinite models of FO theories

[Charlie]

	  Perhaps lightweight criteria can be extracted from this lightweight set of sentences having only infinite models:

1) (Ax)~Fxx
2) (Ax)(Ey)Fxy
3) (Ax)(Ay)(Az)(Fxy & Fyz --> Fxz)


On Jul 30, 2012, at 4:22 PM, Andrei Popescu <uuomul at yahoo.com> wrote:

> Dear FOM subscribers,
> 
> I am searching for (preferably lightweight) syntactic criteria for a first-order theory to admit infinite models.  I would appreciate any pointers to results in the literature.
> 
> All the best, 
>    Andrei Popescu  
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