e/Russo–Dye theorem

Information
has gloss	eng: In mathematics, the Russo–Dye theorem is a result in the field of functional analysis. It states that in a unital C*-algebra, the closure of the convex hull of the unitary elements is the closed unit ball. The theorem was published by B. Russo and H. A. Dye in 1966.
lexicalization	eng: Russo-Dye theorem
lexicalization	eng: Russo–Dye theorem
instance of	c/Unitary operators