Boolean Embeddings of Orthomodular Sets and Quantum Logic

Pavel Pták, Sylvia Pulmannová

Colin James

Neal Zierler, Michael Schlessinger

By a “quantum logic” we mean a pair F, P where P is a set and F is a set of functions from P to the closed real unit interval satisfying three postulates which we describe in intuitive terms here. Cf. [2], [4], [7]. P may be interpreted as the set of events and F the set of states of a “physical system”, and f(x) then becomes the probability of occurrence of the event x in the state f. Since the outcome of an experiment is an estimate for some f(x), or a collection of such estimates, it is natural to identify events which cannot be distinguished by experiment.

Romàn R. Zapatrin

Pavel Pták

Let L L be an orthomodular partially ordered set (“a quantum logic"). Let us say that L L is nearly Boolean if L L is set-representable and if every state on L L is subadditive. We first discuss conditions under which a nearly Boolean OMP must be Boolean. Then we show that in general a nearly Boolean OMP does not have to be Boolean. Moreover, we prove that an arbitrary Boolean algebra may serve as the centre of a (non-Boolean) nearly Boolean OMP.

Peter D. Finch

A weak logical structure is defined as a set of boolean propositional logics in which one can define common operations of negation and implication. The set union of the boolean components of a weak logical structure is a logic of propositions which is an orthocomplemented poset, where orthocomplementation is interpreted as negation and the partial order as implication. It is shown that if one can define on this logic an operation of logical conjunction which has certain plausible properties, then the logic has the structure of an orthomodular lattice. Conversely, if the logic is an orthomodular lattice then the conjunction operation may be defined on it.