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Mirrors > Home > MPE Home > Th. List > fimact | Structured version Visualization version GIF version |
Description: The image by a function of a countable set is countable. (Contributed by Thierry Arnoux, 27-Mar-2018.) |
Ref | Expression |
---|---|
fimact | ⊢ ((𝐴 ≼ ω ∧ Fun 𝐹) → (𝐹 “ 𝐴) ≼ ω) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ctex 8784 | . . 3 ⊢ (𝐴 ≼ ω → 𝐴 ∈ V) | |
2 | imadomg 10336 | . . . 4 ⊢ (𝐴 ∈ V → (Fun 𝐹 → (𝐹 “ 𝐴) ≼ 𝐴)) | |
3 | 2 | imp 408 | . . 3 ⊢ ((𝐴 ∈ V ∧ Fun 𝐹) → (𝐹 “ 𝐴) ≼ 𝐴) |
4 | 1, 3 | sylan 581 | . 2 ⊢ ((𝐴 ≼ ω ∧ Fun 𝐹) → (𝐹 “ 𝐴) ≼ 𝐴) |
5 | simpl 484 | . 2 ⊢ ((𝐴 ≼ ω ∧ Fun 𝐹) → 𝐴 ≼ ω) | |
6 | domtr 8828 | . 2 ⊢ (((𝐹 “ 𝐴) ≼ 𝐴 ∧ 𝐴 ≼ ω) → (𝐹 “ 𝐴) ≼ ω) | |
7 | 4, 5, 6 | syl2anc 585 | 1 ⊢ ((𝐴 ≼ ω ∧ Fun 𝐹) → (𝐹 “ 𝐴) ≼ ω) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 397 ∈ wcel 2104 Vcvv 3437 class class class wbr 5081 “ cima 5603 Fun wfun 6452 ωcom 7744 ≼ cdom 8762 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1795 ax-4 1809 ax-5 1911 ax-6 1969 ax-7 2009 ax-8 2106 ax-9 2114 ax-10 2135 ax-11 2152 ax-12 2169 ax-ext 2707 ax-rep 5218 ax-sep 5232 ax-nul 5239 ax-pow 5297 ax-pr 5361 ax-un 7620 ax-ac2 10265 |
This theorem depends on definitions: df-bi 206 df-an 398 df-or 846 df-3or 1088 df-3an 1089 df-tru 1542 df-fal 1552 df-ex 1780 df-nf 1784 df-sb 2066 df-mo 2538 df-eu 2567 df-clab 2714 df-cleq 2728 df-clel 2814 df-nfc 2887 df-ne 2942 df-ral 3063 df-rex 3072 df-rmo 3285 df-reu 3286 df-rab 3287 df-v 3439 df-sbc 3722 df-csb 3838 df-dif 3895 df-un 3897 df-in 3899 df-ss 3909 df-pss 3911 df-nul 4263 df-if 4466 df-pw 4541 df-sn 4566 df-pr 4568 df-op 4572 df-uni 4845 df-int 4887 df-iun 4933 df-br 5082 df-opab 5144 df-mpt 5165 df-tr 5199 df-id 5500 df-eprel 5506 df-po 5514 df-so 5515 df-fr 5555 df-se 5556 df-we 5557 df-xp 5606 df-rel 5607 df-cnv 5608 df-co 5609 df-dm 5610 df-rn 5611 df-res 5612 df-ima 5613 df-pred 6217 df-ord 6284 df-on 6285 df-suc 6287 df-iota 6410 df-fun 6460 df-fn 6461 df-f 6462 df-f1 6463 df-fo 6464 df-f1o 6465 df-fv 6466 df-isom 6467 df-riota 7264 df-ov 7310 df-oprab 7311 df-mpo 7312 df-1st 7863 df-2nd 7864 df-frecs 8128 df-wrecs 8159 df-recs 8233 df-er 8529 df-map 8648 df-en 8765 df-dom 8766 df-card 9741 df-acn 9744 df-ac 9918 |
This theorem is referenced by: smfpimbor1lem1 44386 |
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