New posts in semigroups

give a counterexample of monoid

Does a non-abelian semigroup without identity exist?

Prove that a semigroup satisfying $a^pb^q=ba$ is commutative

What does $\mathrm{Spec}(\mathbb{Z})\times_{\mathrm{Spec}(\mathbb{F}_{1})}\mathrm{Spec}(\mathbb{Z})$ look like?

In a semigroup does left identity and right inverse imply a group?

Group identities and inverses

Why is a monoid with right identity and left inverse not necessarily a group? [duplicate]

Is there a name for an element $z$ such that $\,zx = z = xz\,$ for all $x$?

Free idempotent semigroup with 3 generators

Just How Strong is Associativity?

Ring without distributive law?

How many associative binary operations there are on a finite set?

Semigroups with no morphisms between them

Show that $S$ is a group if and only if $aS=S=Sa$.

Is a semigroup with unique right identity and left inverse a group?

Eilenberg's rational hierarchy of nonrational automata & languages

Associativity test for a Magma

How to get a group from a semigroup

Describing the Wreath product categorically.

Dynamical System Cocycles: (Semi)Group vs. Monoid Definitions - Examples When is Distinction Important?