Number of idempotents and commutativity
66134
Sufficiently many idempotents and commutativity
1643
Number of reflexive relations defined on a set A with n elements
102721
Number of elements in the ring $\mathbb Z [i]/\langle 2+2i\rangle$
114987
How many connected components does $\mathrm{GL}_n(\mathbb R)$ have?
108742
Proving commutativity of addition for vector spaces
43020
If $I+J=R$, where $R$ is a commutative rng, prove that $IJ=I\cap J$.
60674
Finitely generated idempotent ideals are principal: proof without using Nakayama's lemma
109470
Proof of whether a specific element is in a commutative, invertible monoid.
28485
Commutativity of projection and rotation
62687
Proving Cardinality of Cosets in Abstract Algebra
97878
Are there uncountably many surjections from $\mathbb N$ to $\mathbb N$?
107821
The ring of integers of $\mathbf{Q}[i]$
52354
Given a idempotent endomorphism, show that $M = \ker(f) \oplus \ker (f-\text{id}_M)$
114662
Construction of a specific non-commutative and infinite group (with conditions on the order of the elements)
50241
Cardinality of the quotient ring $\mathbb Z_5[i]/\langle 1+i\rangle$
32741
Idempotents in a ring without unity (rng) and no zero divisors.
27865
What is the number of invertible $n\times n$ matrices in $\operatorname{GL}_n(F)$?