ultraproduct

“Łoś's theorem describes what sentences are true in an ultraproduct.”

First-order Model Theory

“If C is a power of A then this ultraproduct is called an ultrapower of A, and it is sometimes written U-prod A.”

First-order Model Theory

“This is indeed an equivalence relation on the domain of C, and the resulting reduced product is called an ultraproduct of the factors of”

First-order Model Theory

“We refer the reader to the entry on first-order model theory for the notions of direct product (called product there) and ultraproduct.”

Propositional Consequence Relations and Algebraic Logic

“As an example, the notions of quotient, direct product, ultraproduct are defined and examined.”

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