2 citations · 5 across the 11 of their papers we have counts for
10 papers · 1 filter
More on expressibility of satisfiability in submodels and extensions
Nikolai L. Poliakov, Denis I. Saveliev
We study expressibility in infinitary languages of the modal operators associated with satisfiability of sentences of these languages in submodels and extensions of models. We give…
A note on restriction rules
Denis I. Saveliev
We consider a certain class of infinitary rules of inference, called here restriction rules, using of which allows us to deduce complete theories of given models. The first instanc…
On first-order expressibility of satisfiability in submodels
Denis I. Saveliev
Let be regular cardinals, , let be a sentence of the language in a given signature, and let express the fact that holds in a…
On ultrafilter extensions of first-order models and ultrafilter interpretations
Nikolai L. Poliakov, Denis I. Saveliev
There exist two known canonical types of ultrafilter extensions of first-order models; one comes from modal logic and universal algebra, another one from model theory and algebra o…
On modal logics of model-theoretic relations
Denis I. Saveliev, Ilya B. Shapirovsky
Given a class of models, a binary relation between models, and a model-theoretic language , we consider the modal logic and the modal algebra of the…
Ultrafilter extensions do not preserve elementary equivalence
Denis I. Saveliev, Saharon Shelah
We show that there exist models and such that elementarily embeds into but their ultrafilter extensions $β(\mathcal M_1)…