Abstract. The paper is devoted to counterexamples involving the triviality of domains of products and/or adjoints of densely defined operators.

DOI: 10.14232/actasm-018-857-5

AMS Subject Classification (1991): 47A05

Keyword(s): closed operators, trivial domain

Received December 25, 2018 and in final form March 12, 2019. (Registered under 107/2018.)