Question

Prove Q is a theorem of T iff Q is a theorem of every consistent and complete extension of T

score 77 · Answer 1 · 2020-04-02 16:02:15

77

Views

Prove Q is a theorem of T iff Q is a theorem of every consistent and complete extension of T

Published on 02 Apr 2020 - 16:02

score 175 · Answer 2 · 2020-04-06 20:16:27

175

Views

How can there be three model isomorphism classes for this extended theory of unbounded dense linear orders?

Published on 06 Apr 2020 - 20:16

score 96 · Answer 3 · 2020-04-06 22:59:27

96

Views

I am trying to show the relationship between logical consequence of Gamma and being true in every model of Gamma

Published on 06 Apr 2020 - 22:59

score 63 · Answer 4 · 2020-04-08 05:08:50

63

Views

Confusion on Proof of Marker Lemma 2.1.14, $T \vDash \phi \implies \exists \Delta \subseteq T, |\Delta| \in \mathbb{N} \land \Delta \vDash T$

Published on 08 Apr 2020 - 5:08

score 81 · Answer 5 · 2020-04-09 11:00:24

81

Views

Show that a wf $\mathscr{B}(t)⇒(\exists x_i)\mathscr{B}(x_i)$ logically valid if $t$ is free for $x_i$ in $\mathscr{B}$

Published on 09 Apr 2020 - 11:00

score 75 · Answer 6 · 2020-04-09 13:19:45

75

Views

Satisfiability and Truth in First Order Model Theory

Published on 09 Apr 2020 - 13:19

score 77 · Answer 7 · 2020-04-09 14:58:52

77

Views

Prove $(\forall x_i)(\mathscr{B}\rightarrow \mathscr{C})\rightarrow ((\forall x_i)\mathscr{B}⇒(\forall x_i)\mathscr{C})$ is logically valid

Published on 09 Apr 2020 - 14:58

score 33 · Answer 8 · 2020-04-09 20:59:58

33

Views

Extending a model of a multi-sorted algebraic theory by at least one element

Published on 09 Apr 2020 - 20:59

score 133 · Answer 9 · 2026-03-25 06:05:26

133

Views

Why does the converse of the Isomorphism Theorem in first-order logic not hold?

Published on 25 Mar 2026 - 6:05

score 116 · Answer 10 · 2020-04-10 00:17:24

116

Views

Understanding compactness theorem on modeling a sentence

Published on 10 Apr 2020 - 0:17

score 286 · Answer 11 · 2020-04-10 16:59:58

286

Views

If a set of sentences $\Gamma$ has an infinite model, then it has a denumerable model too?

Published on 10 Apr 2020 - 16:59

score 149 · Answer 12 · 2026-03-28 14:55:33

149

Views

How many "$Q$-like" sentences are there?

Published on 28 Mar 2026 - 14:55

score 192 · Answer 13 · 2026-03-26 06:27:42

192

Views

Truth Predicate in Models of ZFC

Published on 26 Mar 2026 - 6:27

score 247 · Answer 14 · 2026-03-25 04:41:39

247

Views

Why do models of ZF which are not $\omega$-models have non-standard formulas whose length is "infinitely large natural numbers"?

Published on 25 Mar 2026 - 4:41

score 199 · Answer 15 · 2020-04-13 15:38:50

199

Views

Witness property implies scapegoat theory in first-order logic

Published on 13 Apr 2020 - 15:38

List Question

Prove Q is a theorem of T iff Q is a theorem of every consistent and complete extension of T

How can there be three model isomorphism classes for this extended theory of unbounded dense linear orders?

I am trying to show the relationship between logical consequence of Gamma and being true in every model of Gamma

Confusion on Proof of Marker Lemma 2.1.14, $T \vDash \phi \implies \exists \Delta \subseteq T, |\Delta| \in \mathbb{N} \land \Delta \vDash T$

Show that a wf $\mathscr{B}(t)⇒(\exists x_i)\mathscr{B}(x_i)$ logically valid if $t$ is free for $x_i$ in $\mathscr{B}$

Satisfiability and Truth in First Order Model Theory

Prove $(\forall x_i)(\mathscr{B}\rightarrow \mathscr{C})\rightarrow ((\forall x_i)\mathscr{B}⇒(\forall x_i)\mathscr{C})$ is logically valid

Extending a model of a multi-sorted algebraic theory by at least one element

Why does the converse of the Isomorphism Theorem in first-order logic not hold?

Understanding compactness theorem on modeling a sentence

If a set of sentences $\Gamma$ has an infinite model, then it has a denumerable model too?

How many "$Q$-like" sentences are there?

Truth Predicate in Models of ZFC

Why do models of ZF which are not $\omega$-models have non-standard formulas whose length is "infinitely large natural numbers"?

Witness property implies scapegoat theory in first-order logic

Trending Questions

Popular # Hahtags

Popular Questions