Description: The addition operation of the extended real number structure. (Contributed by Mario Carneiro, 21-Aug-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | xrsadd | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | xaddf | |
|
2 | xrex | |
|
3 | 2 2 | xpex | |
4 | fex2 | |
|
5 | 1 3 2 4 | mp3an | |
6 | df-xrs | |
|
7 | 6 | odrngplusg | |
8 | 5 7 | ax-mp | |