Metamath Proof Explorer


Definition df-inl

Description: Left injection of a disjoint union. (Contributed by Mario Carneiro, 21-Jun-2022)

Ref Expression
Assertion df-inl inl = x V x

Detailed syntax breakdown

Step Hyp Ref Expression
0 cinl class inl
1 vx setvar x
2 cvv class V
3 c0 class
4 1 cv setvar x
5 3 4 cop class x
6 1 2 5 cmpt class x V x
7 0 6 wceq wff inl = x V x