Prove that formule is true in every realisation of language
41223
How to check, whether the formula is a tautology
15354
Formal proof of $\exists x \forall y P(x,y) \implies \forall y \exists x P(x,y)$
103463
Mantel's Theorem proof verification
132837
Show that any monotone boolean function can be realize by the following connectives.
151561
Proving 'Law of Excluded Middle' in Fitch system
44912
Prove that $ \overline {A^\complement} = (A°)^\complement $
3820
Prove that $||x|-|y||\le |x-y|$
93707
Formal proof for $q \land \neg q \vdash r \land \neg r$
33526
How to prove this beautiful statement on linear forms using induction?
22232
Proving that cardinality of the reals = cardinality of $[0,1]$
68841
Is it true that a language is regular?
106799
Proof Verification: Converse of Intermediate Value Theorem
23707
How can I prove that every word has unique representation?
90970
How to prove the line exist?
6535
Proof of for-all / there-exists "negation"?
103055
Proving the quotient rule for limits
150451
Logic soundness and completeness