Question

Show $\neg(\forall x\phi)\vdash \exists x(\neg \phi)$ using an ND-derivation

score 303 · Answer 1 · 2026-04-15 00:00:35

303

Views

Show $\neg(\forall x\phi)\vdash \exists x(\neg \phi)$ using an ND-derivation

Published on 15 Apr 2026 - 0:00

score 96 · Answer 2 · 2026-04-10 00:04:52

96

Views

Is there a non-empty domain such that its constant terms satisfy a conclusion?

Published on 10 Apr 2026 - 0:04

score 285 · Answer 3 · 2026-04-10 07:08:50

285

Views

Making assumption in natural deduction proof

Published on 10 Apr 2026 - 7:08

score 59 · Answer 4 · 2026-04-14 11:24:08

59

Views

Help me with this propositional logic demonstration

Published on 14 Apr 2026 - 11:24

score 80 · Answer 5 · 2026-04-14 01:55:32

80

Views

Natural deduction proof: C Ʌ D, C ↔ E, D ↔ F |- E Ʌ F

Published on 14 Apr 2026 - 1:55

score 990 · Answer 6 · 2026-04-15 17:42:54

990

Views

Natural deduction proof: $A \vee (B \wedge C) ├ (A \vee B) \wedge (A \vee C)$

Published on 15 Apr 2026 - 17:42

score 272 · Answer 7 · 2026-04-16 15:11:41

272

Views

Fitch natural deduction proof of $\neg D, A \to B, B \to (C \lor D), A \lor C \vdash C$

Published on 16 Apr 2026 - 15:11

score 311 · Answer 8 · 2026-04-10 23:04:00

311

Views

Fitch natural deduction proof with no conditionals

Published on 10 Apr 2026 - 23:04

score 605 · Answer 9 · 2026-04-15 01:37:46

605

Views

Fitch natural deduction proof of $\vdash (\neg P \lor Q) \to (P \to Q)$

Published on 15 Apr 2026 - 1:37

score 521 · Answer 10 · 2026-04-15 06:35:44

521

Views

Fitch natural deduction proof of $\forall x F(x) \lor \forall x G(x) \vdash \forall x (F(x) \lor G(x))$

Published on 15 Apr 2026 - 6:35

score 217 · Answer 11 · 2026-04-16 03:46:55

217

Views

Fitch natural deduction proof of $(P \to Q) \land R, (P \land R) \to S, \neg S \vdash P \to (Q \land R)$

Published on 16 Apr 2026 - 3:46

score 323 · Answer 12 · 2026-04-09 09:17:50

323

Views

Negation Inference with Gentzen Natural Deduction and Sequents?

Published on 09 Apr 2026 - 9:17

score 198 · Answer 13 · 2026-04-14 11:03:30

198

Views

Proving the sequent $A \implies B \vdash \lnot A \lor B$ using natural deduction

Published on 14 Apr 2026 - 11:03

score 215 · Answer 14 · 2026-04-16 02:47:28

215

Views

Fitch natural deduction proof of $\forall x (P(x) \to Q(x)) \to (\forall x (P(x)) \to \forall x (Q(x))$

Published on 16 Apr 2026 - 2:47

score 713 · Answer 15 · 2026-04-14 01:55:30

713

Views

Natural Deduction Proof: A ↔ B |- (C → A) → (C → B)

Published on 14 Apr 2026 - 1:55

List Question

Show $\neg(\forall x\phi)\vdash \exists x(\neg \phi)$ using an ND-derivation

Is there a non-empty domain such that its constant terms satisfy a conclusion?

Making assumption in natural deduction proof

Help me with this propositional logic demonstration

Natural deduction proof: C Ʌ D, C ↔ E, D ↔ F |- E Ʌ F

Natural deduction proof: $A \vee (B \wedge C) ├ (A \vee B) \wedge (A \vee C)$

Fitch natural deduction proof of $\neg D, A \to B, B \to (C \lor D), A \lor C \vdash C$

Fitch natural deduction proof with no conditionals

Fitch natural deduction proof of $\vdash (\neg P \lor Q) \to (P \to Q)$

Fitch natural deduction proof of $\forall x F(x) \lor \forall x G(x) \vdash \forall x (F(x) \lor G(x))$

Fitch natural deduction proof of $(P \to Q) \land R, (P \land R) \to S, \neg S \vdash P \to (Q \land R)$

Negation Inference with Gentzen Natural Deduction and Sequents?

Proving the sequent $A \implies B \vdash \lnot A \lor B$ using natural deduction

Fitch natural deduction proof of $\forall x (P(x) \to Q(x)) \to (\forall x (P(x)) \to \forall x (Q(x))$

Natural Deduction Proof: A ↔ B |- (C → A) → (C → B)

Trending Questions

Popular # Hahtags

Popular Questions