Theorem 0xnn0 9569

Description: Zero is an extended nonnegative integer. (Contributed by AV, 10-Dec-2020.)

Assertion

Ref	Expression
0xnn0	|- 0 e. NN0*

Proof of Theorem 0xnn0

Step	Hyp	Ref	Expression
1		nn0ssxnn0 9566	. 2 |- NN0 C_ NN0*
2		0nn0 9511	. 2 |- 0 e. NN0
3	1, 2	sselii 3235	1 |- 0 e. NN0*

Syntax hints:   e. wcel 2203   0cc0 8127   NN0cn0 9496  NN0*cxnn0 9563

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-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 2214  ax-1cn 8220  ax-icn 8222  ax-addcl 8223  ax-mulcl 8225  ax-i2m1 8232

This theorem depends on definitions:  df-bi 117  df-tru 1401  df-nf 1510  df-sb 1812  df-clab 2219  df-cleq 2225  df-clel 2228  df-nfc 2373  df-v 2815  df-un 3215  df-in 3217  df-ss 3224  df-sn 3695  df-n0 9497  df-xnn0 9564

This theorem is referenced by:  0tonninf  10802