(* Title: ZF/univ.thy ID: $Id$ Author: Lawrence C Paulson, Cambridge University Computer Laboratory Copyright 1992 University of CambridgeThe cumulative hierarchy and a small universe for recursive typesStandard notation for Vset(i) is V(i), but users might want V for a variableNOTE: univ(A) could be a translation; would simplify many proofs! But Ind_Syntax.univ refers to the constant "univ"*)Univ = Arith + Sum + Finite + mono +consts Vfrom :: [i,i]=>i Vset :: i=>i Vrec :: [i, [i,i]=>i] =>i univ :: i=>itranslations "Vset(x)" == "Vfrom(0,x)"defs Vfrom_def "Vfrom(A,i) == transrec(i, %x f. A Un (UN y:x. Pow(f`y)))" Vrec_def "Vrec(a,H) == transrec(rank(a), %x g. lam z: Vset(succ(x)). H(z, lam w:Vset(x). g`rank(w)`w)) ` a" univ_def "univ(A) == Vfrom(A,nat)"end