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| Mirrors > Home > NFE Home > Th. List > df-dif | GIF version | ||
| Description: Define the difference of two classes. See eldif 3222 for membership. (Contributed by SF, 10-Jan-2015.) |
| Ref | Expression |
|---|---|
| df-dif | ⊢ (A ∖ B) = (A ∩ ∼ B) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | cA | . . 3 class A | |
| 2 | cB | . . 3 class B | |
| 3 | 1, 2 | cdif 3207 | . 2 class (A ∖ B) |
| 4 | 2 | ccompl 3206 | . . 3 class ∼ B |
| 5 | 1, 4 | cin 3209 | . 2 class (A ∩ ∼ B) |
| 6 | 3, 5 | wceq 1642 | 1 wff (A ∖ B) = (A ∩ ∼ B) |
| Colors of variables: wff setvar class |
| This definition is referenced by: eldif 3222 nfdif 3233 difeq1 3247 difeq2 3248 difsscompl 3550 compldif 4070 inindif 4076 difexg 4103 nnsucelrlem3 4427 ssfin 4471 sbthlem1 6204 |
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