Relation Proofs on finite set
53101
Is it true that the relation |A| < |B| is a sufficient condition for claiming that $f$ is a bijection?
127596
Composition of equivalence relations
32081
The dual version of trichotomy of cardinality without AC
25834
Proof a set cannot contain its own powerset - Russell's Paradox
151935
Proving the predicate $\forall n \in \mathbb{N} , n \geq 2$ using the Pigeonhole principle
137921
Reflexivity, Transitivity, Symmertry of the square of an relation
147213
Prove that finite unions of compact sets are compact
111032
Proof of Sets involving the Cartesian Product
122828
Proof that TREE(n) where n >= 3 is finite?
62936
Proving equivalencies of two versions of the Axiom of Choice
75007
How can I prove this relation between the elementary set theory and the elementary logic?
96748
Formal deductions on Hilbert system
108922
Cardinality and infinite sets: naturals, integers, rationals, bijections
89167
Cardinality of equivalence relations in $\mathbb{N}$
92249
Every finite set contains its supremum: proof improvement.
94825
Open set as a finite union of closed sets
102824
Countable set of truth assignments satisfying set of well formed formulas