2014/07/08 by Samuele Maschio, Maschio, Samuele, Thomas Streicher +1
Mathematics · #18B25 #Category Theory (math.CT) #FOS: Mathematics #math.CT #msc:18B25
paper · pdf · doi:10.48550/arxiv.1407.2287
arxiv created 2014/07/08 · arxiv updated 2014/07/10
With every pca A and subpca A_# we associate the nested realizability topos RT(A,A_#) within which we identify a class of small maps S giving rise to a model of intuitionistic set theory within RT(A,A_#). For every subtopos E of such a nested realizability topos we construct an induced class SE of small maps in E giving rise to a model of intuitionistic set theory within E. This covers relative realizability toposes, modified relative realizability toposes, the modified realizability topos and van den Berg's recent Herbrand topos.