The constraints of Universal Introduction in logic proofs
38739
Restrictions on universal generalization
123002
Bartle 6.J. proof completion
66636
Problems with introducing ordered pairs axiomatically
143627
Use the Fitch system to prove the tautology (p ∨ ¬p)
35630
Proof for formal languages
156121
Existential-universal vs Universal-existential quantifiers
77507
Induction without a base case
61043
Proofs involving limsup and liminf
46423
Distributivity of quantifiers over logical connectives
151561
Proving 'Law of Excluded Middle' in Fitch system
78290
Countable axiom of choice: why you can't prove it from just ZF
104626
Undecidable language problems.
140194
Using natural deduction to prove that $p \implies q \vdash \lnot p \lor q$
91861
Propositional Logic: p → q, ¬p → r, ¬q → ¬r ⊢ q
113065
Proving equivalences of statements equivalent to AC
52938
Reference request: Standard textbook for first-order predicate logic in english
94617
Showing Consistency and Completeness implies a unique truth assignment