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Mirrors > Home > MPE Home > Th. List > fundif | Structured version Visualization version GIF version |
Description: A function with removed elements is still a function. (Contributed by AV, 7-Jun-2021.) |
Ref | Expression |
---|---|
fundif | ⊢ (Fun 𝐹 → Fun (𝐹 ∖ 𝐴)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | reldif 5820 | . . 3 ⊢ (Rel 𝐹 → Rel (𝐹 ∖ 𝐴)) | |
2 | brdif 5205 | . . . . . . 7 ⊢ (𝑥(𝐹 ∖ 𝐴)𝑦 ↔ (𝑥𝐹𝑦 ∧ ¬ 𝑥𝐴𝑦)) | |
3 | brdif 5205 | . . . . . . 7 ⊢ (𝑥(𝐹 ∖ 𝐴)𝑧 ↔ (𝑥𝐹𝑧 ∧ ¬ 𝑥𝐴𝑧)) | |
4 | pm2.27 42 | . . . . . . . 8 ⊢ ((𝑥𝐹𝑦 ∧ 𝑥𝐹𝑧) → (((𝑥𝐹𝑦 ∧ 𝑥𝐹𝑧) → 𝑦 = 𝑧) → 𝑦 = 𝑧)) | |
5 | 4 | ad2ant2r 745 | . . . . . . 7 ⊢ (((𝑥𝐹𝑦 ∧ ¬ 𝑥𝐴𝑦) ∧ (𝑥𝐹𝑧 ∧ ¬ 𝑥𝐴𝑧)) → (((𝑥𝐹𝑦 ∧ 𝑥𝐹𝑧) → 𝑦 = 𝑧) → 𝑦 = 𝑧)) |
6 | 2, 3, 5 | syl2anb 596 | . . . . . 6 ⊢ ((𝑥(𝐹 ∖ 𝐴)𝑦 ∧ 𝑥(𝐹 ∖ 𝐴)𝑧) → (((𝑥𝐹𝑦 ∧ 𝑥𝐹𝑧) → 𝑦 = 𝑧) → 𝑦 = 𝑧)) |
7 | 6 | com12 32 | . . . . 5 ⊢ (((𝑥𝐹𝑦 ∧ 𝑥𝐹𝑧) → 𝑦 = 𝑧) → ((𝑥(𝐹 ∖ 𝐴)𝑦 ∧ 𝑥(𝐹 ∖ 𝐴)𝑧) → 𝑦 = 𝑧)) |
8 | 7 | alimi 1805 | . . . 4 ⊢ (∀𝑧((𝑥𝐹𝑦 ∧ 𝑥𝐹𝑧) → 𝑦 = 𝑧) → ∀𝑧((𝑥(𝐹 ∖ 𝐴)𝑦 ∧ 𝑥(𝐹 ∖ 𝐴)𝑧) → 𝑦 = 𝑧)) |
9 | 8 | 2alimi 1806 | . . 3 ⊢ (∀𝑥∀𝑦∀𝑧((𝑥𝐹𝑦 ∧ 𝑥𝐹𝑧) → 𝑦 = 𝑧) → ∀𝑥∀𝑦∀𝑧((𝑥(𝐹 ∖ 𝐴)𝑦 ∧ 𝑥(𝐹 ∖ 𝐴)𝑧) → 𝑦 = 𝑧)) |
10 | 1, 9 | anim12i 611 | . 2 ⊢ ((Rel 𝐹 ∧ ∀𝑥∀𝑦∀𝑧((𝑥𝐹𝑦 ∧ 𝑥𝐹𝑧) → 𝑦 = 𝑧)) → (Rel (𝐹 ∖ 𝐴) ∧ ∀𝑥∀𝑦∀𝑧((𝑥(𝐹 ∖ 𝐴)𝑦 ∧ 𝑥(𝐹 ∖ 𝐴)𝑧) → 𝑦 = 𝑧))) |
11 | dffun2 6563 | . 2 ⊢ (Fun 𝐹 ↔ (Rel 𝐹 ∧ ∀𝑥∀𝑦∀𝑧((𝑥𝐹𝑦 ∧ 𝑥𝐹𝑧) → 𝑦 = 𝑧))) | |
12 | dffun2 6563 | . 2 ⊢ (Fun (𝐹 ∖ 𝐴) ↔ (Rel (𝐹 ∖ 𝐴) ∧ ∀𝑥∀𝑦∀𝑧((𝑥(𝐹 ∖ 𝐴)𝑦 ∧ 𝑥(𝐹 ∖ 𝐴)𝑧) → 𝑦 = 𝑧))) | |
13 | 10, 11, 12 | 3imtr4i 291 | 1 ⊢ (Fun 𝐹 → Fun (𝐹 ∖ 𝐴)) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ∧ wa 394 ∀wal 1531 ∖ cdif 3943 class class class wbr 5152 Rel wrel 5686 Fun wfun 6547 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1789 ax-4 1803 ax-5 1905 ax-6 1963 ax-7 2003 ax-8 2100 ax-9 2108 ax-ext 2696 ax-sep 5303 ax-nul 5310 ax-pr 5432 |
This theorem depends on definitions: df-bi 206 df-an 395 df-or 846 df-3an 1086 df-tru 1536 df-fal 1546 df-ex 1774 df-sb 2060 df-clab 2703 df-cleq 2717 df-clel 2802 df-ral 3051 df-rex 3060 df-rab 3419 df-v 3463 df-dif 3949 df-un 3951 df-ss 3963 df-nul 4325 df-if 4533 df-sn 4633 df-pr 4635 df-op 4639 df-br 5153 df-opab 5215 df-id 5579 df-xp 5687 df-rel 5688 df-cnv 5689 df-co 5690 df-fun 6555 |
This theorem is referenced by: fundmge2nop 14507 fun2dmnop 14509 |
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