Deriving ¬R from {R↔(R∨(P∧¬P)),R↔¬P,¬P→(P↔(Q→Q)),P→Q}
65379
Deriving $\neg R$ from $\{R↔(R∨(P∧¬P)), R↔¬P, ¬P→(P↔(Q→Q)), P→Q\}$
36626
Multiplication cancellation property by Peano axioms
72068
Finding Boolean/Logical Expressions for truth tables in algebraic normal form(ANF)
100421
How to write this boolean expression using only NOR gates?
15354
Formal proof of $\exists x \forall y P(x,y) \implies \forall y \exists x P(x,y)$
80183
Deduction of "Disjunction elimination"
113605
In Fitch, how does one prove "(P → Q)" from the premise "(¬P ∨ Q)"?
50178
\qed for theorems without proofs
22842
The Interpretation of $|\psi|^2$ and the No-Clone Theorem
96748
Formal deductions on Hilbert system
46939
Natural deduction, Proof $\vdash$ $P\Rightarrow(Q\Rightarrow P)$
136427
Given $∃y.∀x.p(x,y)$, use the Fitch system to prove $∀x.∃y.p(x,y)$
103653
Interpretations and models in propositional logic
32009
Prove $\;\big((p\rightarrow q) \lor (p \rightarrow r)\big) \rightarrow (q\lor r)\equiv p \lor q \lor r$ without use of a truth table.
56351
Prove that these statements $(A \lor \neg B)$ and $\neg A \to \neg B$ are logically equivalent
21035
Clarifying on how if p,q is logically equivalent to p only if q
93410
How to prove ~ (~P & ~Q) : P ∨ Q by natural deduction