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| Mirrors > Home > MPE Home > Th. List > df-symdif | Structured version Visualization version GIF version | ||
| Description: Define the symmetric difference of two classes. Alternate definitions are dfsymdif2 4236, dfsymdif3 4281 and dfsymdif4 4234. (Contributed by Scott Fenton, 31-Mar-2012.) |
| Ref | Expression |
|---|---|
| df-symdif | ⊢ (𝐴 △ 𝐵) = ((𝐴 ∖ 𝐵) ∪ (𝐵 ∖ 𝐴)) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | cA | . . 3 class 𝐴 | |
| 2 | cB | . . 3 class 𝐵 | |
| 3 | 1, 2 | csymdif 4227 | . 2 class (𝐴 △ 𝐵) |
| 4 | 1, 2 | cdif 3923 | . . 3 class (𝐴 ∖ 𝐵) |
| 5 | 2, 1 | cdif 3923 | . . 3 class (𝐵 ∖ 𝐴) |
| 6 | 4, 5 | cun 3924 | . 2 class ((𝐴 ∖ 𝐵) ∪ (𝐵 ∖ 𝐴)) |
| 7 | 3, 6 | wceq 1540 | 1 wff (𝐴 △ 𝐵) = ((𝐴 ∖ 𝐵) ∪ (𝐵 ∖ 𝐴)) |
| Colors of variables: wff setvar class |
| This definition is referenced by: symdifcom 4229 symdifeq1 4230 nfsymdif 4232 elsymdif 4233 difsssymdif 4238 dfsymdif3 4281 symdif0 5061 symdifv 5062 symdifid 5063 |
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