In mathematics, an O*-algebra is an algebra of possibly unbounded operators defined on a dense subspace of a Hilbert space. The original examples were described by and , who studied some examples of O*-algebras, called Borchers algebras, arising from the Wightman axioms of quantum field theory. and began the systematic study of algebras of unbounded operators.
Does this next sentence follow, given the preceding text?
Unbounded operators are always positive integers.

Select from:
 1). Yes.
 2). It's impossible to say.
 3). No.
2).