Database
REAL AND COMPLEX NUMBERS
Derive the basic properties from the field axioms
Infinity and the extended real number system
1xr
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renfdisj
Metamath Proof Explorer
Ascii
Unicode
Theorem
1xr
Description:
1
is an extended real number.
(Contributed by
Glauco Siliprandi
, 2-Jan-2022)
Ref
Expression
Assertion
1xr
⊢
1
∈
ℝ
*
Proof
Step
Hyp
Ref
Expression
1
1re
⊢
1
∈
ℝ
2
1
rexri
⊢
1
∈
ℝ
*