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Mirrors > Home > MPE Home > Th. List > df-xr | Structured version Visualization version Unicode version |
Description: Define the set of extended reals that includes plus and minus infinity. Definition 12-3.1 of [Gleason] p. 173. (Contributed by NM, 13-Oct-2005.) |
Ref | Expression |
---|---|
df-xr |
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Step | Hyp | Ref | Expression |
---|---|---|---|
1 | cxr 9700 |
. 2
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2 | cr 9564 |
. . 3
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3 | cpnf 9698 |
. . . 4
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4 | cmnf 9699 |
. . . 4
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5 | 3, 4 | cpr 3982 |
. . 3
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6 | 2, 5 | cun 3414 |
. 2
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7 | 1, 6 | wceq 1455 |
1
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Colors of variables: wff setvar class |
This definition is referenced by: ressxr 9710 ltrelxr 9721 ssxr 9729 xrex 11328 pnfxr 11441 mnfxr 11443 elxr 11445 |
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