Theorem onn0 4503

Description: The class of all ordinal numbers is not empty. (Contributed by NM, 17-Sep-1995.)

Assertion

Ref	Expression
onn0	|- On =/= (/)

Proof of Theorem onn0

Step	Hyp	Ref	Expression
1		0elon 4495	. 2 |- (/) e. On
2		ne0i 3503	. 2 |- ( (/) e. On -> On =/= (/) )
3	1, 2	ax-mp 5	1 |- On =/= (/)

Syntax hints:   e. wcel 2202   =/= wne 2403   (/)c0 3496   Oncon0 4466

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 619  ax-in2 620  ax-io 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-ext 2213  ax-nul 4220

This theorem depends on definitions:  df-bi 117  df-tru 1401  df-nf 1510  df-sb 1811  df-clab 2218  df-cleq 2224  df-clel 2227  df-nfc 2364  df-ne 2404  df-ral 2516  df-rex 2517  df-v 2805  df-dif 3203  df-in 3207  df-ss 3214  df-nul 3497  df-pw 3658  df-uni 3899  df-tr 4193  df-iord 4469  df-on 4471

This theorem is referenced by: (None)