This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: Addition of real numbers in terms of intermediate signed reals. (Contributed by NM, 10-May-1996) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | addresr |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 0r | ||
| 2 | addcnsr | ||
| 3 | 2 | an4s | |
| 4 | 1 1 3 | mpanr12 | |
| 5 | 0idsr | ||
| 6 | 1 5 | ax-mp | |
| 7 | 6 | opeq2i | |
| 8 | 4 7 | eqtrdi |