New posts in model-theory

Has a conjecture ever originally been decided by constructing the proof with mathematical logic?

logic model-theory math-history proof-theory type-theory

Comparing countable models of ZFC

logic set-theory model-theory

Non-axiomatisability and ultraproducts

logic model-theory

How can we know we're not accidentally talking about non-standard integers?

logic model-theory proof-theory turing-machines incompleteness

Is $\Bbb R$ definable in $(\Bbb C,0,1,+,*,\exp)$?

logic model-theory first-order-logic

Identifying the finite symmetric groups

group-theory logic finite-groups model-theory

What is the definition of a definition?

logic definition computer-science model-theory formal-systems

Impossibility of expressing "there are at least n+1 objects" without using existential quantifiers

Example of non-isomorphic structures which are elementarily equivalent

logic model-theory

Two model theory questions regarding infinitely axiomatizable classes of structures

What kind of compactness does "expanding $\mathbb{R}$ by constants" have?

logic set-theory model-theory

Indiscernible to create descending chain of elementary models

How do model theorists define structures?

logic model-theory axioms

Intersection of Algebraic Topology/Geometry and Model Theory/Set Theory

algebraic-geometry set-theory algebraic-topology model-theory

Are $C([0,1])$ and $C(\mathbb{R})$ elementarily equivalent as rings?

abstract-algebra general-topology logic ring-theory model-theory

Is the class of infinite sets along with some certain other finite sets an axiomatizable class?

Which types of first-order signatures have proper pseudo-elementary classes?

Model existence for infinitary logics

logic set-theory model-theory

Is this a characterization of well-orders?

logic model-theory order-theory

Are there number systems corresponding to higher cardinalities than the real numbers?

field-theory cardinals model-theory infinity