![]() |
Mathbox for BJ |
< Previous
Next >
Nearby theorems |
|
Mirrors > Home > MPE Home > Th. List > Mathboxes > df-bj-pr1 | Structured version Visualization version GIF version |
Description: Definition of the first projection of a class tuple. New usage is discouraged because the precise definition is generally unimportant compared to the characteristic properties bj-pr1eq 33767, bj-pr11val 33770, bj-pr21val 33778, bj-pr1ex 33771. (Contributed by BJ, 6-Apr-2019.) (New usage is discouraged.) |
Ref | Expression |
---|---|
df-bj-pr1 | ⊢ pr1 𝐴 = (∅ Proj 𝐴) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | cA | . . 3 class 𝐴 | |
2 | 1 | bj-cpr1 33765 | . 2 class pr1 𝐴 |
3 | c0 4173 | . . 3 class ∅ | |
4 | 3, 1 | bj-cproj 33755 | . 2 class (∅ Proj 𝐴) |
5 | 2, 4 | wceq 1507 | 1 wff pr1 𝐴 = (∅ Proj 𝐴) |
Colors of variables: wff setvar class |
This definition is referenced by: bj-pr1eq 33767 bj-pr1un 33768 bj-pr1val 33769 bj-pr1ex 33771 |
Copyright terms: Public domain | W3C validator |