# Questions tagged [lo.logic]

first-order and higher-order logic, model theory, set theory, proof theory, computability theory, formal languages, definability, interplay of syntax and semantics, constructive logic, intuitionism, philosophical logic, modal logic, completeness, Gödel incompleteness, decidability, undecidability, theories of truth, truth revision, consistency.

**1**

**0**answers

### A game-theoretic ordering on null sets

**-1**

**0**answers

### Is there difference in notion of measurability in classical versus constructive?

**0**

**0**answers

### Physics applications of quantum logic

**1**

**0**answers

### An analogue to Robinson's theorem for Kalmar-elementary functions

**10**

**0**answers

### Quantifier swap in Banach space theory

**4**

**0**answers

### Undecidable statements of second-order arithmetic

**-2**

**0**answers

### DNF conversion in Propositional Logic: Commutative Property [closed]

**6**

**0**answers

### Are there analogues of real-valued measurability for larger powersets?

**-3**

**0**answers

### Generate distinct integers with OR [closed]

**3**

**1**answer

### NF and incompleteness

**6**

**0**answers

### Topological Vaught's conjecture for special theories

**2**

**2**answers

### Is there any reasonable non-regular Gödel numbering of the language of arithmetic?

**43**

**4**answers

### Category theory and set theory: just a different language, or different foundation of mathematics?

**6**

**1**answer

### Can we recover an inner model of CH after forgetting some generic information?

**14**

**1**answer

### Reverse mathematics of Cousin's lemma

**10**

**0**answers

### Does Merkurjev's argument help Voevodsky's program?

**0**

**1**answer

### What is the relevant literature –if any– on real-valued functions on sets and their Boolean combinations? [closed]

**49**

**1**answer

### In the two-person Killing the Hydra game, what is the winning strategy?

**15**

**0**answers

### Positive set theory and the “co-Russell” set

**0**

**0**answers

### At which large cardinal property Ackermann set theory + finitization rule would stop?

**9**

**1**answer

### Does every cofinal branch through Kleene's O compute true arithmetic?

**0**

**0**answers

### Is Separation in $V$ a theorem schema of Ackermann set theory minus subsets?

**0**

**0**answers

### Is there a formula with one free variable in NBG that defines a class that does not exist?

**1**

**0**answers

### “The” axiom of induction up to recursive ordinal $\alpha$ in $\mbox{PRA}$

**7**

**1**answer

### Natural $\Pi_1$ sentence independent of PA

**11**

**0**answers

### Isomorphic free groups have bijective generating sets

**10**

**0**answers

### How wealthy are canonical inner models?

**3**

**1**answer

### Turing machines with all runs decidable

**23**

**1**answer

### Are Conway's combinatorial games the “monster model” of any familiar theory?

**13**

**3**answers

### Tarski's truth theorem — semantic or syntactic?

**6**

**2**answers

### Comparing “axiomatized function spaces”

**8**

**1**answer

### The lattice of analogues of Robinson's $Q$

**7**

**1**answer

### Is Axiom of Choice equivalent to its version for families of sets, indexed by ordinals? [duplicate]

**4**

**1**answer

### How can we know the well-foundedness of $\epsilon_0$?

**2**

**0**answers

### Definability in countable nonstandard models of Peano arithmetic

**21**

**2**answers

### Does the “three-set-lemma” imply the Axiom of Choice?

**8**

**0**answers

### Does any 'logical' theory have a bounded ∞-pretopos as syntactic category?

**28**

**2**answers

### Who introduced direct limits?

**6**

**1**answer

### Complexity of a combinatorial constraint

**54**

**4**answers

### Bourbaki's definition of the number 1

**2**

**0**answers

### ITTMs with higher types

**13**

**1**answer

### History of well founded relations

**11**

**3**answers

### The constancy principle in choiceless constructive foundations

**7**

**0**answers

### “Local” compactness properties beyond $\mathcal{L}_{\omega_1,\omega}$?

**9**

**1**answer

### Toposes in which countable choice is true but dependent choice isn't

**0**

**0**answers

### Can inaccessibility be captured in relational flat set theory?

**3**

**0**answers

### Global choice for models of complete theories in $\mathsf{ZFC}$

**8**

**2**answers

### Can nonstandard fields contain $\mathbb R$ in different ways?

**5**

**0**answers

### Inner models with all sets generic

**11**

**0**answers