Description: Alternate proof of 0re . (Contributed by NM, 19-Feb-2005) (Proof modification is discouraged.) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 0reALT | ⊢ 0 ∈ ℝ |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ax-1cn | ⊢ 1 ∈ ℂ | |
| 2 | 1 | subidi | ⊢ ( 1 − 1 ) = 0 |
| 3 | 1re | ⊢ 1 ∈ ℝ | |
| 4 | 3 3 | resubcli | ⊢ ( 1 − 1 ) ∈ ℝ |
| 5 | 2 4 | eqeltrri | ⊢ 0 ∈ ℝ |