Its semantics are defined using finite structure (mathematical logic).
The set of σ-sentences valid in all finite structures is not recursively enumerable.
Another contribution of his was the introduction of finite and non-continuous structures into geometry.
In other words, we find the following finite clausal structures:
To study computation we need a theory of finite structures.
For a single finite structure this is always possible.
Is a Language L expressive enough to describe exactly those finite structures that have certain property P in common (up to isomorphy)?
The queries - when restricted to finite structures - correspond to the computational problems of traditional complexity theory.
Conversely, the table of any finite structure can be encoded by a finite string.
Some of the finite structures considered in graph theory have names, sometimes inspired by the graph's topology, and sometimes after their discoverer.