Description: it1ei without ax-mulcom . (See sn-mullid for commuted version). (Contributed by SN, 1-Jun-2024)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | sn-it1ei | ⊢ ( i · 1 ) = i |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | sn-1ticom | ⊢ ( 1 · i ) = ( i · 1 ) | |
| 2 | ax-icn | ⊢ i ∈ ℂ | |
| 3 | sn-mullid | ⊢ ( i ∈ ℂ → ( 1 · i ) = i ) | |
| 4 | 2 3 | ax-mp | ⊢ ( 1 · i ) = i |
| 5 | 1 4 | eqtr3i | ⊢ ( i · 1 ) = i |