# Total set

A set $\Sigma$ of linear functionals on a vector space $E$ separating the points of $E$, that is, such that for any non-zero vector $x \in E$ there is an $f \in \Sigma$ with $f(x) \neq 0$.

#### Comments

A total set in the sense above is also, and more precisely, called a total set of linear functions, [a1].

More generally, a set $M \subset T$, where $T$ is a topological vector space, is called a total set or fundamental set if the linear span of $M$ is dense in $T$. If the algebraic dual $E^*$ of $E$, is given the weak topology (so that $E^* \simeq \prod_{\alpha \in A} K$,where $K$ is the base field and $\{ e_\alpha : \alpha \in A \}$ is an (algebraic) basis for $E$), the two definitions for a set $\Sigma \subset E^*$ agree.

#### References

[a1] | S. Rolewicz, "Metric linear spaces" , Reidel (1985) pp. 44 |

[a2] | G. Köthe, "Topological vector spaces" , 1 , Springer (1969) pp. 132, 247ff |

**How to Cite This Entry:**

Total set.

*Encyclopedia of Mathematics.*URL: http://encyclopediaofmath.org/index.php?title=Total_set&oldid=51659