Set-Operational Properties of Semiatoms in Non-additive Measure Theory

Metainduction in Operational Set Theory

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Completeness in Operational Set Theory

This note is concerned with operational set theory, a concept that was introduced in Sanchis [8], via the sysstem G, a partially formalized set theory. The leit motiv of this approach is the predicativity principle, that we understand as a general principle in the sense that the universe of sets is not a well defined totality, and quantification over the universe may be allowed only under sever...

Elementary Constructive Operational Set Theory

We introduce an operational set theory in the style of [5] and [17]. The theory we develop here is a theory of constructive sets and operations. One motivation behind constructive operational set theory is to merge a constructive notion of set ([1], [2]) with some aspects which are typical of explicit mathematics [14]. In particular, one has non-extensional operations (or rules) alongside exten...

Ontological Questions about Operational Set Theory

On Feferman's operational set theory OST

We study OST and some of its most important extensions primarily from a proof-theoretic perspective, determine their consistency strengths by exhibiting equivalent systems in the realm of traditional set theory and introduce a new and interesting extension of OST which is conservative over ZFC.