Logical equivalence with tautology
68265
Why is it sensical for a proposition with a false antecedent to validate to true?
105455
Prove that "injective function $f:X\to Y$ exists" and "surjective function $g:Y\to X$ exists" is logically equivalent.
32180
Why is "$A$ unless $B$" equivalent to $A \lor B$?
13074
Prove Logical Equivalence
52585
How to prove that $[(p \to q) \land (q \to r)] \to (p \to r)$ is a tautology without using the truth table?
89506
Union of disjoint sets : Equivalence relations
28281
Different standards for writing down logical quantifiers in a formal way
3663
Finding counterexamples in elementary set theory.
25997
Conditions Equivalent to Injectivity
114476
Problem solving Logical Equivalence Question
3465
Equivalence relations and power sets.
125950
Proof strategy involving first order logic for existential quantification at very beginning
69043
The equivalence relation generated by a relation
126870
Show that axiom of replacement implies from the Axiom of Specification [Proof Verification]
127596
Composition of equivalence relations
56351
Prove that these statements $(A \lor \neg B)$ and $\neg A \to \neg B$ are logically equivalent
62936
Proving equivalencies of two versions of the Axiom of Choice