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Mirrors > Home > NFE Home > Th. List > difeq12d | GIF version |
Description: Equality deduction for class difference. (Contributed by FL, 29-May-2014.) |
Ref | Expression |
---|---|
difeq12d.1 | ⊢ (φ → A = B) |
difeq12d.2 | ⊢ (φ → C = D) |
Ref | Expression |
---|---|
difeq12d | ⊢ (φ → (A ∖ C) = (B ∖ D)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | difeq12d.1 | . . 3 ⊢ (φ → A = B) | |
2 | 1 | difeq1d 3384 | . 2 ⊢ (φ → (A ∖ C) = (B ∖ C)) |
3 | difeq12d.2 | . . 3 ⊢ (φ → C = D) | |
4 | 3 | difeq2d 3385 | . 2 ⊢ (φ → (B ∖ C) = (B ∖ D)) |
5 | 2, 4 | eqtrd 2385 | 1 ⊢ (φ → (A ∖ C) = (B ∖ D)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 = wceq 1642 ∖ cdif 3206 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1546 ax-5 1557 ax-17 1616 ax-9 1654 ax-8 1675 ax-6 1729 ax-7 1734 ax-11 1746 ax-12 1925 ax-ext 2334 |
This theorem depends on definitions: df-bi 177 df-or 359 df-an 360 df-nan 1288 df-tru 1319 df-ex 1542 df-nf 1545 df-sb 1649 df-clab 2340 df-cleq 2346 df-clel 2349 df-nfc 2478 df-v 2861 df-nin 3211 df-compl 3212 df-in 3213 df-dif 3215 |
This theorem is referenced by: nnsucelr 4428 |
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