ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  df-ndx GIF version

Definition df-ndx 11992
Description: Define the structure component index extractor. See theorem ndxarg 12012 to understand its purpose. The restriction to ensures that ndx is a set. The restriction to some set is necessary since I is a proper class. In principle, we could have chosen or (if we revise all structure component definitions such as df-base 11995) another set such as the set of finite ordinals ω (df-iom 4509). (Contributed by NM, 4-Sep-2011.)
Assertion
Ref Expression
df-ndx ndx = ( I ↾ ℕ)

Detailed syntax breakdown of Definition df-ndx
StepHypRef Expression
1 cnx 11986 . 2 class ndx
2 cid 4214 . . 3 class I
3 cn 8740 . . 3 class
42, 3cres 4545 . 2 class ( I ↾ ℕ)
51, 4wceq 1332 1 wff ndx = ( I ↾ ℕ)
Colors of variables: wff set class
This definition is referenced by:  ndxarg  12012
  Copyright terms: Public domain W3C validator