Is a finite monoid with left cancellation property always a group?
13834
Show that G is a group, if G is finite, the operation is associative, and cancellation law holds
156459
infinite monoid H that is not a free monoid and contains a free monoid as a submonoid
96123
Element of maximal order in alternating group $A_{10}$: how to prove this is it?
113708
Correspondence between Ext group and extensions (from Weibel's book)
21610
The monoid of fractions associated with the submonoid of cancellable elements of a commutative monoid E
110390
Order of group $GL_{2}\left( \mathbb{F}_{p}\right) $
23517
Presentation $\langle x,y,z\mid xyx^{-1}y^{-2},yzy^{-1}z^{-2},zxz^{-1}x^{-2}\rangle$ of group equal to trivial group
120254
Nowhere commutative semigroups = rectangular bands?
137931
Problem from "The Theory of Finite Groups" by Kurzweil and Stellmacher
84985
Is a semigroup with unique right identity and left inverse a group?
125613
Free idempotent semigroup with 3 generators
21958
Splitting of conjugacy class in alternating group
29538
Does a non-abelian semigroup without identity exist?
7536
Is there an idempotent element in a finite semigroup?
109470
Proof of whether a specific element is in a commutative, invertible monoid.
120495
Does this correctly interpret the "$\cong$" between groups as "$=$" between sets?
74452
On a uniqueness proof for solutions of $\ a + x = b\,$ in a group