Tag: symbolic-logic

21 Selection of logical connectives {¬,∨,∧,⇒,⇔} in set theory? 2015-09-07T05:10:37.827

17 What is the difference between Law of Excluded Middle and Principle of Bivalence? 2012-07-10T21:42:02.837

12 How to prove (A v B), (A → C), (B → D) therefore (C v D) 2019-09-27T04:34:33.723

10 What's the difference among the logical relations :=, =, and ≡? 2014-12-24T09:18:44.680

7 Is it true that (P∧Q≡P)⇔(Q≡⊤)? 2015-09-29T05:27:08.603

7 How do proofs about logic fit into a logical framework? 2020-01-16T21:01:35.257

6 What is the explicit reasoning behind proof by contradiction? 2016-06-02T03:20:31.977

6 In Fitch, how does one prove "(P → Q)" from the premise "(¬P ∨ Q)"? 2016-11-20T07:08:04.203

6 What exactly is a first-order logic? 2019-06-15T06:04:00.673

5 What exactly are the identity rules in logic? 2015-10-31T03:01:55.047

5 What does the truth-value of a material implication represent? 2016-06-19T00:20:50.103

5 Is it possible to construct infinitely many non-equivalent formulas in predicate logic? 2019-08-05T03:12:44.673

5 Can/Do there exist any quantifiers other than "there exists" and "for all"? 2020-01-02T21:27:52.090

5 Why does Gensler's Star Test not work on some syllogisms? 2020-07-13T05:51:29.140

4 Can knowledge about argumentation be sufficient for philosophical logic without too symbolic or mathematical concepts? 2012-09-30T17:15:37.553

4 Disjunctive Syllogism in a Fitch Style System 2013-10-10T22:25:38.993

4 help with deductive proof 2014-08-30T17:33:41.333

4 Fitch style disjunction elimination 2015-04-27T14:26:05.050

4 Is there a formalized logic for adpositional connectives? 2015-05-09T21:02:41.317

4 Subformulas of the WFF (∀x) ((∀y) ((x ∈ y) ∨ (y ∈ x ))) 2015-09-25T23:20:47.773

4 What it the relationship between Type theory and logic? 2015-09-29T16:16:14.953

4 Prove ∀w(∀v((v=w∧φ(v))⇔φ(w))) 2015-10-19T00:08:52.830

4 need some guidance for this easy symbolic logic question 2015-11-04T17:34:14.807

4 Symbolic Logic Proof: Leprechauns Exist? 2015-12-14T05:31:06.983

4 Fitch Proof - LPL Exercise 8.17 2016-08-21T16:57:24.683

4 Propositional Logic: How to prove the contraposition in the Fitch system? 2016-10-07T22:25:47.243

4 P <=> (Q v R), P, -Q⊢R Propositional Logic Question 2016-10-28T00:33:26.403

4 Is there a logical symbol for "why"? 2017-11-28T05:59:48.590

4 What, at present, are the major unsolved problems of logic? 2018-04-24T12:34:48.593

4 How to show that (P & Q) v (~P v ~ Q) is a theorem in SD 2018-07-19T20:16:08.247

4 What would be an intuitive understanding of Peirce's law? 2018-11-27T20:52:28.690

4 What is the logical law proving "if not p then q" is equivalent to "p or q"? 2019-08-30T23:20:27.077

4 What does the colon (:) mean in conjunction with material implication? 2020-02-11T21:45:17.237

4 Are there famous unsolved problems in logic akin to the Millenium Prize problems? 2020-07-08T07:23:14.063

4 What does the symbol ":=" mean in formal logic? 2020-10-25T02:40:53.940

3 Prove P v ~P using most basic rules? 2013-09-29T21:51:52.643

3 Anyone can help me with proving ~(AvB) |- ~(BvA) via natural deduction? 2014-10-13T20:11:42.110

3 Prove A ∨ D from A ∨ (B ∧ C) and (¬ B ∨ ¬ C) ∨ D ( LPL Q6.26) without using --> or material implication 2015-02-22T19:26:06.007

3 Is there a uniform way of differentiating sufficient and necessary conditions? 2015-09-29T12:58:05.053

3 How to prove ¬¬(A ∨ B) leads to ¬¬(B ∨ A)? 2015-10-14T15:29:31.150

3 Classical logic derivation question 2015-10-23T12:27:15.120

3 In modern logic, why does "All S is P" contradict "Some S is not P"? 2016-04-02T10:10:38.160

3 Formal proof : predicate logic 2016-11-16T22:35:55.517

3 How would one go about proving the following statement in predicate logic? 2016-11-29T08:54:04.347

3 Implication Introduction formulated as a theorem? 2017-02-02T19:20:48.537

3 What are the rules for a zero-premise derivation involving disjunctions? 2017-07-25T04:11:55.527

3 Getting started with reading papers in (philosophical) logic 2017-09-10T10:26:27.140

3 Step by step natural deduction: (T > E) ^ (A > L) /... (T v A) > (E v L) 2018-05-22T18:09:18.967

3 Symbolic Logic - Negation Introduction 2018-06-18T22:05:31.493

3 How to prove P ∨ Q : ~ (~P & ~Q) with natural deduction 2018-08-24T22:00:45.380

3 meaning of (r .⊃. s ⊃ r) [the syntax meaning] 2018-09-25T01:46:04.597

3 2 simple Formal Fitch Proofs 2018-10-08T01:44:03.673

3 Can something proved by contradiction always be proved without a proof by contradiction? 2018-11-18T01:49:56.097

3 proof for relational predicate logic 2018-12-04T00:29:11.733

3 S5 proof of ⊢◻(◻P→◻Q)∨◻(◻Q→◻P) 2019-01-30T01:03:15.140

3 Does 'until' imply a conditional with a negative consequent? 2019-02-11T21:02:03.863

3 Can classical logic have deduction with infinite steps 2019-05-26T13:52:34.417

3 What is the difference between logical consistency and logical entailment in deductive logic? 2019-07-12T15:20:19.247

3 Are verb tenses actually irrelevant in logic? 2019-09-01T23:36:01.010

3 Logic terminology: does "conditional" etc refer to the operator or the WFF? 2019-09-19T23:37:14.850

3 What's the difference between a second-order relation and a relation between objects? 2019-09-27T15:50:04.393

2 Conditional disjunction equivalence proof using FItch 2014-10-09T11:28:21.113

2 How to give proof for Q ∧ R with the premisse ¬(¬¬¬P ∨ P)? 2014-11-23T12:09:04.930

2 Representation of Categorical Syllogism in Symbolic Logic 2015-03-12T05:17:08.483

2 can you express universal quantification ∀x(Px ≡ Qx) simply as Px ≡ Qx? 2016-01-26T14:15:03.803

2 Is there a difference between 'only if' and 'if and only if' 2016-02-24T08:34:59.030

2 Verum, Falsum, Atoms 2016-03-12T20:18:48.200

2 Is there a symbolic formulation of modal realism? 2016-04-15T17:57:45.770

2 Suppose A is a set of premises of an argument and B the conclusion of that argument. Prove that if A U {¬B} ⊢ ⊥, then A ⊢ B 2016-04-30T01:50:21.453

2 How to express possession in predicate calculus 2016-07-12T05:01:13.810

2 How to prove 1. ~(KvF) 2. ~F=>(KvC) 3. (GVC)=>~H / ~(KvH) using natural deduction 2016-10-11T19:28:11.807

2 Is this a valid move in a proof or does this create a contradiction? 2016-11-30T05:19:07.910

2 I am stuck on how to prove the contradiction of R(b,a) can anybody help me? 2016-12-02T05:16:13.740

2 Problems with Existential Instantiation 2017-02-10T17:11:40.723

2 Why do “L” and “M” name the strong and weak modal operators in modal logic? 2017-03-15T13:23:53.347

2 Proof for the Rule of Absorption in Propositional Logic? 2017-06-10T02:45:26.447

2 Logic question regarding a logical truth 2017-08-04T12:24:05.980

2 Is it logically correct to say that if A implies B then not A implies not B? 2017-08-31T15:53:37.230

2 If it is not all wrong, then I have a problem in line 25. Can anybody help, please? 2017-10-21T19:04:36.260

2 Prove (¬P ∨ Q) ↔ (P → Q) 2017-10-24T18:20:55.970

2 In fitch, S → (R ∨ P), P → (¬R → Q) ∴ S → (Q ∨ R) 2017-12-12T18:16:51.107

2 Negation of a statement 2018-01-15T21:32:24.907

2 FOL and Tarski's world logic connectives question 2018-02-28T03:50:00.967

2 Deriving "(p.q) v (p.r) from "p.(q v r)"? 2018-04-03T09:34:34.763

2 An example for (∃y)(Fy→(∀x)Fx)? 2018-04-07T17:26:03.653

2 Monadic Predicate and Polyadic Predicate? 2018-06-03T14:49:22.013

2 Predicate Logic - Existential Elimination 2018-06-30T02:20:20.963

2 Predicate Logic - Universal Introduction 2018-06-30T05:36:33.880

2 Need help translating a formal definition into FOL 2018-07-04T10:29:55.927

2 Is it possible to define argument validity as a formula? 2018-08-30T01:21:44.660

2 Logic Either..Or 2018-09-11T07:58:43.070

2 Are Statements with Existential Quantifiers General or Particular? 2018-10-12T19:26:52.377

2 McGee's Counterexample to Modus Ponens 2018-10-18T02:46:19.837

2 How does one prove ‘(B→C)→¬A’ from ‘(A→B)∨C’ and ‘(A→¬C)’ in Fitch? 2018-10-30T05:44:27.973

2 Completeness/Soundess of Second Order Logic 2018-11-05T18:04:50.030

2 Fitch Biconditional Proof Help? 2018-11-20T09:04:36.573

2 How to prove (PvQ) & (RvS) : ((P&R) v (P&S)) v ((Q&R) v (Q&S)) by Natural deduction 2018-12-20T18:33:03.540

2 How would i go about using natural deduction to prove this argument is valid? 2019-01-15T06:22:41.543

2 Classical logic, symbolic logic, higher-order logic, First-order logic? Learning from scratch 2019-01-15T09:33:53.237