Description: 1 is a multiplicative identity for _i (see sn-mulid2 for commuted version). (Contributed by SN, 1-Jun-2024)
Ref | Expression | ||
---|---|---|---|
Assertion | it1ei | |- ( _i x. 1 ) = _i |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sn-1ticom | |- ( 1 x. _i ) = ( _i x. 1 ) |
|
2 | ax-icn | |- _i e. CC |
|
3 | sn-mulid2 | |- ( _i e. CC -> ( 1 x. _i ) = _i ) |
|
4 | 2 3 | ax-mp | |- ( 1 x. _i ) = _i |
5 | 1 4 | eqtr3i | |- ( _i x. 1 ) = _i |