Theorem nnssre 9146

Description: The positive integers are a subset of the reals. (Contributed by NM, 10-Jan-1997.) (Revised by Mario Carneiro, 16-Jun-2013.)

Assertion

Ref	Expression
nnssre	|- NN C_ RR

Proof of Theorem nnssre

Step	Hyp	Ref	Expression
1		1re 8177	. 2 |- 1 e. RR
2		peano2re 8314	. . 3 |- ( x e. RR -> ( x + 1 ) e. RR )
3	2	rgen 2585	. 2 |- A. x e. RR ( x + 1 ) e. RR
4		peano5nni 9145	. 2 |- ( ( 1 e. RR /\ A. x e. RR ( x + 1 ) e. RR ) -> NN C_ RR )
5	1, 3, 4	mp2an 426	1 |- NN C_ RR

Syntax hints:   e. wcel 2202   A.wral 2510   C_ wss 3200  (class class class)co 6017   RRcr 8030   1c1 8032   + caddc 8034   NNcn 9142

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 716  ax-5 1495  ax-7 1496  ax-gen 1497  ax-ie1 1541  ax-ie2 1542  ax-8 1552  ax-10 1553  ax-11 1554  ax-i12 1555  ax-bndl 1557  ax-4 1558  ax-17 1574  ax-i9 1578  ax-ial 1582  ax-i5r 1583  ax-ext 2213  ax-sep 4207  ax-cnex 8122  ax-resscn 8123  ax-1re 8125  ax-addrcl 8128

This theorem depends on definitions:  df-bi 117  df-tru 1400  df-nf 1509  df-sb 1811  df-clab 2218  df-cleq 2224  df-clel 2227  df-nfc 2363  df-ral 2515  df-v 2804  df-in 3206  df-ss 3213  df-int 3929  df-inn 9143

This theorem is referenced by:  nnsscn  9147  nnre  9149  nnred  9155  nn0ssre  9405  nninfdclemp1  13070  nninfdclemf1  13072