projective set
in descriptive set theory, a subset of a Polish space constructible by taking complements and projections of an analytic set
en-US/pɹəˈd͡ʒɛktɪv ˈsɛt/
en-GB/pɹəˈd͡ʒɛktɪv ˈsɛt/
in descriptive set theory, a subset of a Polish space constructible by taking complements and projections of an analytic set