Mathematics Stack Exchange
Mathematics Stack Exchange

Questions tagged [magma]

A magma is a set together with a binary operation on this set. (For questions about the computer algebra system named Magma, use the [magma-cas] tag instead.)

A magma (also called groupoid) is a set $M$ together with a binary operation $M\times M\to M$.

For questions about the Magma computer algebra system, use the tag .

191 questions
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Cantor-Bernstein theorem for magmas

Let $G$, $H$ be magmas. $G_1 \subset G$ - submagma of $G$, $H_1 \subset H$ - submagma of $H$. Let $G \simeq H_1$, $H \simeq G_1$. Is true that $G \simeq H$?
Albert
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Term for a magma with a left identity?

Is there a term for a magma $(M,*)$ that contains at least one left identity element, but not necessarily a right identity element? I'm looking for a term that requires only $$\exists e \in M \text{ such that},\, \forall a \in M,\, e*a = a.$$
Tyrrell McAllister
  • 173
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1 answer

Generating subsets of a finite magma

I am trying to write a program which, given a multiplication table of a finite magma $(G, *)$, should produce at least one (or all possible) generating subset $S$ of minimal cardinality. More precisely $S \subset G, \ |G| = n \in \mathbb{N}$. Let…
Drinkwater
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Is there a magma with the following property?

Does there exist an infinite magma with the following property: Let $n$ be a positive integer greater than or equal to $2$. For all $x_1,...,x_n$, if $x_1,...x_n$ are all distinct, then all products where one and only one each of $x_1,...,x_n$…
user107952
  • 20,508
0
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Showing properties of a set of functions

Let $A$ be a set of at least $2$ elements and $M=\left\{q\mid q:A\rightarrow A\text{ is a function}\right\}$. $($a$)$ $f\in M$ is left absorbing if and only if $f$ is a constant function. $($b$)$ $M$ has no right absorbing elements. For part…
user281997