Brouwer-Zadeh (fuzzy-intuitionistic) posets for unsharp quantum mechanics (Q685154)

A Brouwer-Zadeh poset [the author and \textit{G. Nistico}, Fuzzy Sets Syst. 33, 165-190 (1989; Zbl 0682.03036)] is a poset with two orthocomplementations: a regular degenerate Zadeh one, and a weak Brouwer one. The set of all effects on a Hilbert space \(H\), i.e., of all Hermitian operators \(A\) on \(H\) such that \(0\leq A\leq I\), is the most important example of Brouwer-Zadeh posets, which models measurement of unsharp quantum mechanics, and this example is studied in frames of B-Z posets in more detail.