Description: Left injection of a disjoint union. (Contributed by Mario Carneiro, 21-Jun-2022)
Ref | Expression | ||
---|---|---|---|
Assertion | df-inl | |- inl = ( x e. _V |-> <. (/) , x >. ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | cinl | |- inl |
|
1 | vx | |- x |
|
2 | cvv | |- _V |
|
3 | c0 | |- (/) |
|
4 | 1 | cv | |- x |
5 | 3 4 | cop | |- <. (/) , x >. |
6 | 1 2 5 | cmpt | |- ( x e. _V |-> <. (/) , x >. ) |
7 | 0 6 | wceq | |- inl = ( x e. _V |-> <. (/) , x >. ) |