Description: The "additive group" of the extended reals is a magma. (Contributed by AV, 30-Jan-2020)
Ref | Expression | ||
---|---|---|---|
Assertion | xrsmgm | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | xaddcl | |
|
2 | 1 | rgen2 | |
3 | 0xr | |
|
4 | xrsbas | |
|
5 | xrsadd | |
|
6 | 4 5 | ismgmn0 | |
7 | 3 6 | ax-mp | |
8 | 2 7 | mpbir | |