Theorem inton 6420

Description: The intersection of the class of ordinal numbers is the empty set. (Contributed by NM, 20-Oct-2003.)

Assertion

Ref	Expression
inton	⊢ ∩ On = ∅

Proof of Theorem inton

Step	Hyp	Ref	Expression
1		0elon 6416	. 2 ⊢ ∅ ∈ On
2		int0el 4943	. 2 ⊢ (∅ ∈ On → ∩ On = ∅)
3	1, 2	ax-mp 5	1 ⊢ ∩ On = ∅

Syntax hints:   = wceq 1568   ∈ wcel 2141  ∅c0 4285  ∩ cint 4911  Oncon0 6360

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1823  ax-4 1837  ax-5 1938  ax-6 1995  ax-7 2036  ax-8 2143  ax-9 2151  ax-ext 2733  ax-nul 5268

This theorem depends on definitions:  df-bi 210  df-an 401  df-or 861  df-3an 1103  df-tru 1571  df-fal 1581  df-ex 1808  df-sb 2095  df-clab 2740  df-cleq 2753  df-clel 2836  df-ne 2957  df-ral 3078  df-rex 3088  df-rab 3415  df-v 3455  df-dif 3907  df-un 3909  df-ss 3921  df-nul 4286  df-if 4487  df-pw 4563  df-sn 4589  df-pr 4591  df-op 4595  df-uni 4872  df-int 4912  df-br 5109  df-tr 5218  df-po 5569  df-so 5570  df-fr 5614  df-we 5616  df-ord 6363  df-on 6364

This theorem is referenced by:  bday0  27980