Theorem 0xnn0 9615

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 9612	. 2 |- NN0 C_ NN0*
2		0nn0 9557	. 2 |- 0 e. NN0
3	1, 2	sselii 3245	1 |- 0 e. NN0*

Syntax hints:   e. wcel 2209   0cc0 8169   NN0cn0 9542  NN0*cxnn0 9609

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 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-ext 2220  ax-1cn 8262  ax-icn 8264  ax-addcl 8265  ax-mulcl 8267  ax-i2m1 8274

This theorem depends on definitions:  df-bi 117  df-tru 1405  df-nf 1514  df-sb 1816  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-v 2823  df-un 3224  df-in 3226  df-ss 3233  df-sn 3711  df-n0 9543  df-xnn0 9610

This theorem is referenced by:  0tonninf  10855