Prove: (p ∧ q) ∨ (q ∧ r) ∨ (r ∧ p) ≡ (p ∨ q) ∧ (q ∨ r) ∧ (r ∨ p)
36114
conjunction of disjunctions and disjunction of conjunctions
121544
Proof by Induction: $2(\sqrt{n+1} - \sqrt{n}) < \frac{1}{\sqrt{n}} < 2(\sqrt{n}-\sqrt{n-1})$
135750
Prove that if a and b are integers, then there are unique integers q and r such that $a = bq + r$, $-|b|/2 < r \le |b|/2$
11168
Proof of divisibility: if $a|b$ and $a|(b+c)$ then $a|c$
13466
Prove that if a|b and b|c then a|c using a column proof that has steps in the first column and the reason for the step in the second column.
70311
Trying to prove (A ∩ B) − C = (A − C) ∩ (B − C)
9282
Prove using natural deduction $((P \land Q) \rightarrow R) \vdash (P \rightarrow R) \lor (Q\rightarrow R)$
121720
Given ∃x.¬p(x), use the Fitch System to prove ¬∀x.p(x).
20736
Prove the relation $R$ in $N \times N$ defined by $(a,b) \simeq (c,d)$ iff $ad=bc$ is an equivalence relation.
113605
In Fitch, how does one prove "(P → Q)" from the premise "(¬P ∨ Q)"?
157625
How to prove conditional in Coq?
136427
Given $∃y.∀x.p(x,y)$, use the Fitch system to prove $∀x.∃y.p(x,y)$
118039
How prove $p!|(a+1)$ if $p!|a^p+1$
61103
Prove that $\mathbb{|Q| = |Q\times Q|}$
45323
How to prove $\vdash\neg P\to (P\to Q)$?
48368
Prove using Natural Deduction in predicate logic $(\forall x\ P(x))\to Q ⊢ \exists x (P(x)\to Q)$
88104
Prove "$(p \lor q) \land (\neg p \lor r)) \rightarrow (q \lor r)$" is a tautology