Why do we need formal logic proofs when we have truth tables?
103342
Why should we care about syntactic proofs if we can show semantically that statements are true?
103463
Mantel's Theorem proof verification
51863
Logical Conditional Truth Table Rationale
93742
Show that the conditional statement is a tautology without using a truth table
91861
Propositional Logic: p → q, ¬p → r, ¬q → ¬r ⊢ q
28281
Different standards for writing down logical quantifiers in a formal way
77759
How do i prove that $(p \vee q) \wedge (\neg p \vee r) \rightarrow (q \vee r)$ is a tautology without using the truth table?
143627
Use the Fitch system to prove the tautology (p ∨ ¬p)
128111
Why is a deductive closure an intersection of maximally consistent sets?
113605
In Fitch, how does one prove "(P → Q)" from the premise "(¬P ∨ Q)"?
41622
Converting truth tables to boolean expressions
32244
Propositional Logic - Deduction
578
In classical logic, why is $(p\Rightarrow q)$ True if both $p$ and $q$ are False?
22193
Why, logically, is proof by contradiction valid?
15504
In classical logic, why is $(p\Rightarrow q)$ True if $p$ is False and $q$ is True?
93557
Intuitively, why does (B → S) ≡ (¬B ∨ S)?
134319
When induction proofs need a choice function