Theorem ressxr 8282

Description: The standard reals are a subset of the extended reals. (Contributed by NM, 14-Oct-2005.)

Assertion

Ref	Expression
ressxr	|- RR C_ RR*

Proof of Theorem ressxr

Step	Hyp	Ref	Expression
1		ssun1 3372	. 2 |- RR C_ ( RR u. { +oo , -oo } )
2		df-xr 8277	. 2 |- RR* = ( RR u. { +oo , -oo } )
3	1, 2	sseqtrri 3263	1 |- RR C_ RR*

Syntax hints:   u. cun 3199   C_ wss 3201   {cpr 3674   RRcr 8091   +oocpnf 8270   -oocmnf 8271   RR*cxr 8272

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 2213

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-v 2805  df-un 3205  df-in 3207  df-ss 3214  df-xr 8277

This theorem is referenced by:  rexpssxrxp  8283  rexr  8284  0xr  8285  rexrd  8288  ltrelxr  8299  iooval2  10211  fzval2  10308  seq3coll  11169  summodclem2a  12022  prodmodclem2a  12217  ismet2  15165  qtopbas  15333  tgqioo  15366