Identity type between A and B being non-empty implies non-emptiness of A and B?
130620
Identity type between A and B being non-empty implies non-emptiness of A and B?
80892
Does $\wp(A \cap B) = \wp(A) \cap \wp(B)$ hold? How to prove it?
11509
Relationship between $\operatorname{ord}(ab), \operatorname{ord}(a)$, and $\operatorname{ord}(b)$
101803
A\(B∩C) = (A\B) ∪ (A\C) how to prove?
76790
Condition to guarantee $f=0$ on $[a,b]$
85819
A non-polyhedral pair $(X,A)$ with both $X$ and $A$ polyhedral
118824
What is the complement of empty set?
125348
Does $\det(A + B) = \det(A) + \det(B)$ hold?
127664
Inverse elements in the absence of identities/associativity.
87928
Proof of logical equivalence of biconditional and other proposition
46875
The identity morphism in $\mathbf{Set}$ is the identity function
83714
$A \in B$ vs. $A \subset B$ for proofs
131983
Prove that $A \subset B$ if and only if $A \setminus B = \emptyset$
83981
How to prove those "curious identities"?
111038
If there is a unique left identity, then it is also a right identity
104124
Prove or disprove: $A-(B-C) = (A-B)-C$
140167
Proving $A+A'B=A+B$ without truth tables