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| Mirrors > Home > NFE Home > Th. List > df-cup | GIF version | ||
| Description: Define the cup function. (Contributed by SF, 9-Feb-2015.) | 
| Ref | Expression | 
|---|---|
| df-cup | ⊢ Cup = (x ∈ V, y ∈ V ↦ (x ∪ y)) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | ccup 5742 | . 2 class Cup | |
| 2 | vx | . . 3 setvar x | |
| 3 | vy | . . 3 setvar y | |
| 4 | cvv 2860 | . . 3 class V | |
| 5 | 2 | cv 1641 | . . . 4 class x | 
| 6 | 3 | cv 1641 | . . . 4 class y | 
| 7 | 5, 6 | cun 3208 | . . 3 class (x ∪ y) | 
| 8 | 2, 3, 4, 4, 7 | cmpt2 5654 | . 2 class (x ∈ V, y ∈ V ↦ (x ∪ y)) | 
| 9 | 1, 8 | wceq 1642 | 1 wff Cup = (x ∈ V, y ∈ V ↦ (x ∪ y)) | 
| Colors of variables: wff setvar class | 
| This definition is referenced by: cupvalg 5813 fncup 5814 cupex 5817 | 
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