Theorem nnssre 9040

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 8071	. 2 |- 1 e. RR
2		peano2re 8208	. . 3 |- ( x e. RR -> ( x + 1 ) e. RR )
3	2	rgen 2559	. 2 |- A. x e. RR ( x + 1 ) e. RR
4		peano5nni 9039	. 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 2176   A.wral 2484   C_ wss 3166  (class class class)co 5944   RRcr 7924   1c1 7926   + caddc 7928   NNcn 9036

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 711  ax-5 1470  ax-7 1471  ax-gen 1472  ax-ie1 1516  ax-ie2 1517  ax-8 1527  ax-10 1528  ax-11 1529  ax-i12 1530  ax-bndl 1532  ax-4 1533  ax-17 1549  ax-i9 1553  ax-ial 1557  ax-i5r 1558  ax-ext 2187  ax-sep 4162  ax-cnex 8016  ax-resscn 8017  ax-1re 8019  ax-addrcl 8022

This theorem depends on definitions:  df-bi 117  df-tru 1376  df-nf 1484  df-sb 1786  df-clab 2192  df-cleq 2198  df-clel 2201  df-nfc 2337  df-ral 2489  df-v 2774  df-in 3172  df-ss 3179  df-int 3886  df-inn 9037

This theorem is referenced by:  nnsscn  9041  nnre  9043  nnred  9049  nn0ssre  9299  nninfdclemp1  12821  nninfdclemf1  12823