Rules for Arithmetic with Two Equivalent Infinities
34138
Cardinal number subtraction
79349
The Aleph numbers and infinity in calculus.
102307
Discrete Math Proofs Involving Real Numbers
152382
Can an infinite set A be larger than an infinite set B but still have the same cardinality?
114550
Well-ordering theorem and second-order logic
89506
Union of disjoint sets : Equivalence relations
112080
Proving the Product Rule for exponents with the same base
17022
Definable real numbers
77548
Given an arbitrary infinite set $S$, how to construct an injection $\mathbb{N} \to S$ with the Axiom of Choice?
81250
Infinitude of prime numbers
7733
If A is infinite, does there have to exist a subset of A that is equivalent to A?
126698
measurability of a function -equivalent conditions
52429
Explicit countable elementary extension of $\mathbb{N}$
101163
Does there exist a universal formula of first-order logic that is satisfiable only by structures with infinite domains?
100977
Infinite subset with pairwise comprime elements
33164
Formal basis for variable substitution in limits
69043
The equivalence relation generated by a relation