Generating set of a topological algebra

Generating set of a topological algebra

A generating set "S" of a topological algebra (e.g., a Banach algebra) "A" is a subset of "A" such that the smallest closed subalgebra of "A" containing "S" is "A" itself.

Since polynomials are dense in the set C [0,1] of continuous functions on the interval [0,1] ,the set {x} (and any of its supersets) consisting of the function xmapsto x is a generating set of the "Banach algebra" C [0,1] . However, it is not a generating set of the "algebra" C [0,1] (since in the definition of a generating set of an algebra the word "closed" is omitted).

A generating set is sometimes called a system of generators.

A structure (e.g., a topological algebra) "A" is called n-generated if there exists a generating set of "A" consisting of at most n elements. If "A" is n-generated for some finite n (resp., for n=1), then "A" is called finitely generated (resp., singly generated).


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