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Theorem 1xr 7957
Description: 1 is an extended real number. (Contributed by Glauco Siliprandi, 2-Jan-2022.)
Assertion
Ref Expression
1xr 1 ∈ ℝ*

Proof of Theorem 1xr
StepHypRef Expression
1 1re 7898 . 2 1 ∈ ℝ
21rexri 7956 1 1 ∈ ℝ*
Colors of variables: wff set class
Syntax hints:  wcel 2136  1c1 7754  *cxr 7932
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 699  ax-5 1435  ax-7 1436  ax-gen 1437  ax-ie1 1481  ax-ie2 1482  ax-8 1492  ax-10 1493  ax-11 1494  ax-i12 1495  ax-bndl 1497  ax-4 1498  ax-17 1514  ax-i9 1518  ax-ial 1522  ax-i5r 1523  ax-ext 2147  ax-1re 7847
This theorem depends on definitions:  df-bi 116  df-tru 1346  df-nf 1449  df-sb 1751  df-clab 2152  df-cleq 2158  df-clel 2161  df-nfc 2297  df-v 2728  df-un 3120  df-in 3122  df-ss 3129  df-xr 7937
This theorem is referenced by:  fprodge1  11580
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