Theorem ttcwf3

Description: The sets whose transitive closures are sets are precisely the well-founded sets, assuming Regularity. (Contributed by Matthew House, 6-Apr-2026)

	Ref	Expression
Assertion	ttcwf3	Could not format assertion : No typesetting found for |- ( TC+ A e. _V <-> A e. U. ( R1 " On ) ) with typecode |-

Proof

Step	Hyp	Ref	Expression
1		ttcwf2	Could not format ( TC+ A e. _V <-> TC+ A e. U. ( R1 " On ) ) : No typesetting found for |- ( TC+ A e. _V <-> TC+ A e. U. ( R1 " On ) ) with typecode |-
2		ttcwf	Could not format ( A e. U. ( R1 " On ) <-> TC+ A e. U. ( R1 " On ) ) : No typesetting found for |- ( A e. U. ( R1 " On ) <-> TC+ A e. U. ( R1 " On ) ) with typecode |-
3	1 2	bitr4i	Could not format ( TC+ A e. _V <-> A e. U. ( R1 " On ) ) : No typesetting found for |- ( TC+ A e. _V <-> A e. U. ( R1 " On ) ) with typecode |-