A set with associative operation such that $xa=b$ and $ay=b$ can be solved, is a group
13834
Show that G is a group, if G is finite, the operation is associative, and cancellation law holds
111032
Proof of Sets involving the Cartesian Product
93031
How to show that $\mathbb{Z}$ with the operation $m*n=m+(-1)^m n$ is associative?
77791
Proving an inclusion related to algebraic sets and interpreting it
157582
Inverse of $ab$ and its order in a group with relations $a^2=e=b^6$ and $ab=b^4a$
12459
Associativity of symmetric difference of sets
77859
Prove or find a counter example to the claim that for all sets A,B,C if A ∩ B = B ∩ C = A ∩ C = Ø then A∩B∩C ≠ Ø
142631
Show that A has the same cardinality as $A\setminus\{x,y,z\}$
116527
Validating a proof for necessary and sufficient conditions on sets A & B such that $P(A) \cup P(B) = P(A\cup B)$
46240
Show that if $A$ and $B$ are sets, then $(A\cap B) \cup (A\cap \overline{B})=A$.
66563
Is $ (A∪B)×(C∩D)=(A∪C)×(B∪D)$ true for all sets A,B,C and D?
22482
How can an ordered pair be expressed as a set?
44405
Prove XOR is commutative and associative?
8483
A Particular Two-Variable System in a Group
1707
How does one prove that addition on $\mathbb{R}$ is associative?
89506
Union of disjoint sets : Equivalence relations
62687
Proving Cardinality of Cosets in Abstract Algebra