# 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.

**-7**

**0**answers

### A reform of logic to secure naive set theory? [closed]

**0**

**0**answers

### Regarding equality of screens (beginning of successive regions)

**0**

**1**answer

### Can we define cardinality that works under weaker grounds than Scott's cardinals?

**0**

**1**answer

### How may a largest fixed-point be defined in second order logic?

**0**

**0**answers

### Does this hereditary size based definition of cardinality work under grounds weaker than regularity and choice?

**6**

**1**answer

### Why can't we embed Tarski's truth in PA?

**8**

**2**answers

### Is it consistent to have a function that is sensitive to subset relation from the power set of a set to that set?

**4**

**1**answer

### Lob theorem for Robinson arithmetic

**5**

**1**answer

### Does bounded Zermelo construct any cumulative hierarchy?

**8**

**3**answers

### Is there a theory in a finite language that is computably axiomatizable but not by a finite number of axiom schemas?

**2**

**0**answers

### Is the existence of undecidable propositions decidable?

**8**

**0**answers

### Distributivity of certain infinite products

**0**

**1**answer

### Linear programming with exponential inequalities and rational variables

**2**

**1**answer

### Constructivity of two problems on a standard simplex?

**42**

**1**answer

### Who first characterized the real numbers as the unique complete ordered field?

**-2**

**0**answers

### Is the following provable in Zermelo–Fraenkel Set Theory? [migrated]

**4**

**1**answer

### Formal proof of $ZFC \vdash CON(\ulcorner ZFC-P\urcorner)$

**3**

**1**answer

### Is every extension of ZFC interpretable in a finite extension of ZC + rank?

**9**

**1**answer

### Distributivity of ! over?

**5**

**3**answers

### Is the class of power-associative binars finitely axiomatizable?

**4**

**0**answers

### Algebraic applications of an order-theoretic idiom of recursion

**1**

**0**answers

### Completeness of certain formal deduction system

**0**

**0**answers

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

**2**

**1**answer

### Physics applications of quantum logic

**4**

**0**answers

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

**11**

**0**answers

### Quantifier swap in Banach space theory

**6**

**0**answers

### Undecidable statements of second-order arithmetic

**7**

**0**answers

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

**3**

**1**answer

### NF and incompleteness

**8**

**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?

**50**

**5**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?

**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

**24**

**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