Pestov–Ionin theorem
= Pestov–Ionin theorem
{wiki=Pestov–Ionin_theorem}
The Pestov–Ionin theorem is a result in the field of mathematical logic that deals with the preservation of certain properties in structures, particularly in the context of countable models. Although it is a specialized topic, the theorem itself is typically discussed within the framework of model theory, which studies the relationships between formal languages and their interpretations (or models).