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.
All operators in Hilbert Space are unbounded.
The statement is in the correct category because the excerpt does not specify if operators in Hilbert Space can be either bound or unbound. The system may have had difficulty due to the unspecified wording in the excerpt.
( z1 limit :polarity - :ARG1 ( z2 person :ARG0-of ( z3 operate :location ( z4 space :name ( z5 name :op "Hilbert" :op "Space" ) ) ) :mod ( z6 all ) ) )