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Mirrors > Home > MPE Home > Th. List > dff4 | Structured version Visualization version GIF version |
Description: Alternate definition of a mapping. (Contributed by NM, 20-Mar-2007.) |
Ref | Expression |
---|---|
dff4 | ⊢ (𝐹:𝐴⟶𝐵 ↔ (𝐹 ⊆ (𝐴 × 𝐵) ∧ ∀𝑥 ∈ 𝐴 ∃!𝑦 ∈ 𝐵 𝑥𝐹𝑦)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dff3 6858 | . 2 ⊢ (𝐹:𝐴⟶𝐵 ↔ (𝐹 ⊆ (𝐴 × 𝐵) ∧ ∀𝑥 ∈ 𝐴 ∃!𝑦 𝑥𝐹𝑦)) | |
2 | df-br 5058 | . . . . . . . 8 ⊢ (𝑥𝐹𝑦 ↔ 〈𝑥, 𝑦〉 ∈ 𝐹) | |
3 | ssel 3958 | . . . . . . . . 9 ⊢ (𝐹 ⊆ (𝐴 × 𝐵) → (〈𝑥, 𝑦〉 ∈ 𝐹 → 〈𝑥, 𝑦〉 ∈ (𝐴 × 𝐵))) | |
4 | opelxp2 5590 | . . . . . . . . 9 ⊢ (〈𝑥, 𝑦〉 ∈ (𝐴 × 𝐵) → 𝑦 ∈ 𝐵) | |
5 | 3, 4 | syl6 35 | . . . . . . . 8 ⊢ (𝐹 ⊆ (𝐴 × 𝐵) → (〈𝑥, 𝑦〉 ∈ 𝐹 → 𝑦 ∈ 𝐵)) |
6 | 2, 5 | syl5bi 243 | . . . . . . 7 ⊢ (𝐹 ⊆ (𝐴 × 𝐵) → (𝑥𝐹𝑦 → 𝑦 ∈ 𝐵)) |
7 | 6 | pm4.71rd 563 | . . . . . 6 ⊢ (𝐹 ⊆ (𝐴 × 𝐵) → (𝑥𝐹𝑦 ↔ (𝑦 ∈ 𝐵 ∧ 𝑥𝐹𝑦))) |
8 | 7 | eubidv 2665 | . . . . 5 ⊢ (𝐹 ⊆ (𝐴 × 𝐵) → (∃!𝑦 𝑥𝐹𝑦 ↔ ∃!𝑦(𝑦 ∈ 𝐵 ∧ 𝑥𝐹𝑦))) |
9 | df-reu 3142 | . . . . 5 ⊢ (∃!𝑦 ∈ 𝐵 𝑥𝐹𝑦 ↔ ∃!𝑦(𝑦 ∈ 𝐵 ∧ 𝑥𝐹𝑦)) | |
10 | 8, 9 | syl6bbr 290 | . . . 4 ⊢ (𝐹 ⊆ (𝐴 × 𝐵) → (∃!𝑦 𝑥𝐹𝑦 ↔ ∃!𝑦 ∈ 𝐵 𝑥𝐹𝑦)) |
11 | 10 | ralbidv 3194 | . . 3 ⊢ (𝐹 ⊆ (𝐴 × 𝐵) → (∀𝑥 ∈ 𝐴 ∃!𝑦 𝑥𝐹𝑦 ↔ ∀𝑥 ∈ 𝐴 ∃!𝑦 ∈ 𝐵 𝑥𝐹𝑦)) |
12 | 11 | pm5.32i 575 | . 2 ⊢ ((𝐹 ⊆ (𝐴 × 𝐵) ∧ ∀𝑥 ∈ 𝐴 ∃!𝑦 𝑥𝐹𝑦) ↔ (𝐹 ⊆ (𝐴 × 𝐵) ∧ ∀𝑥 ∈ 𝐴 ∃!𝑦 ∈ 𝐵 𝑥𝐹𝑦)) |
13 | 1, 12 | bitri 276 | 1 ⊢ (𝐹:𝐴⟶𝐵 ↔ (𝐹 ⊆ (𝐴 × 𝐵) ∧ ∀𝑥 ∈ 𝐴 ∃!𝑦 ∈ 𝐵 𝑥𝐹𝑦)) |
Colors of variables: wff setvar class |
Syntax hints: ↔ wb 207 ∧ wa 396 ∈ wcel 2105 ∃!weu 2646 ∀wral 3135 ∃!wreu 3137 ⊆ wss 3933 〈cop 4563 class class class wbr 5057 × cxp 5546 ⟶wf 6344 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1787 ax-4 1801 ax-5 1902 ax-6 1961 ax-7 2006 ax-8 2107 ax-9 2115 ax-10 2136 ax-11 2151 ax-12 2167 ax-ext 2790 ax-sep 5194 ax-nul 5201 ax-pr 5320 |
This theorem depends on definitions: df-bi 208 df-an 397 df-or 842 df-3an 1081 df-tru 1531 df-ex 1772 df-nf 1776 df-sb 2061 df-mo 2615 df-eu 2647 df-clab 2797 df-cleq 2811 df-clel 2890 df-nfc 2960 df-ne 3014 df-ral 3140 df-rex 3141 df-reu 3142 df-rab 3144 df-v 3494 df-sbc 3770 df-dif 3936 df-un 3938 df-in 3940 df-ss 3949 df-nul 4289 df-if 4464 df-sn 4558 df-pr 4560 df-op 4564 df-uni 4831 df-br 5058 df-opab 5120 df-id 5453 df-xp 5554 df-rel 5555 df-cnv 5556 df-co 5557 df-dm 5558 df-rn 5559 df-iota 6307 df-fun 6350 df-fn 6351 df-f 6352 df-fv 6356 |
This theorem is referenced by: exfo 6863 |
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