Ramsey proved that, if is a formula in the Bernays–Schönfinkel class with one free variable, then either :\phi (x)\}}
is finite, or :\neg \phi (x)\}}
is finite.
This class of logic formulas is also sometimes referred as effectively propositional (EPR) since it can be effectively translated into propositional logic formulas by a process of grounding or instantiation.
The satisfiability problem for this class is NEXPTIME-complete.
Applications
Efficient algorithms for deciding satisfiability of EPR have been integrated into SMT solvers.