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Mirrors > Home > MPE Home > Th. List > Mathboxes > abrexctf | Structured version Visualization version GIF version |
Description: An image set of a countable set is countable, using bound-variable hypotheses instead of distinct variable conditions. (Contributed by Thierry Arnoux, 8-Mar-2017.) |
Ref | Expression |
---|---|
mptctf.1 | ⊢ Ⅎ𝑥𝐴 |
Ref | Expression |
---|---|
abrexctf | ⊢ (𝐴 ≼ ω → {𝑦 ∣ ∃𝑥 ∈ 𝐴 𝑦 = 𝐵} ≼ ω) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eqid 2737 | . . 3 ⊢ (𝑥 ∈ 𝐴 ↦ 𝐵) = (𝑥 ∈ 𝐴 ↦ 𝐵) | |
2 | 1 | rnmpt 5821 | . 2 ⊢ ran (𝑥 ∈ 𝐴 ↦ 𝐵) = {𝑦 ∣ ∃𝑥 ∈ 𝐴 𝑦 = 𝐵} |
3 | mptctf.1 | . . . 4 ⊢ Ⅎ𝑥𝐴 | |
4 | 3 | mptctf 30769 | . . 3 ⊢ (𝐴 ≼ ω → (𝑥 ∈ 𝐴 ↦ 𝐵) ≼ ω) |
5 | rnct 10136 | . . 3 ⊢ ((𝑥 ∈ 𝐴 ↦ 𝐵) ≼ ω → ran (𝑥 ∈ 𝐴 ↦ 𝐵) ≼ ω) | |
6 | 4, 5 | syl 17 | . 2 ⊢ (𝐴 ≼ ω → ran (𝑥 ∈ 𝐴 ↦ 𝐵) ≼ ω) |
7 | 2, 6 | eqbrtrrid 5086 | 1 ⊢ (𝐴 ≼ ω → {𝑦 ∣ ∃𝑥 ∈ 𝐴 𝑦 = 𝐵} ≼ ω) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 = wceq 1543 {cab 2714 Ⅎwnfc 2884 ∃wrex 3059 class class class wbr 5050 ↦ cmpt 5132 ran crn 5549 ωcom 7641 ≼ cdom 8621 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1803 ax-4 1817 ax-5 1918 ax-6 1976 ax-7 2016 ax-8 2112 ax-9 2120 ax-10 2141 ax-11 2158 ax-12 2175 ax-ext 2708 ax-rep 5176 ax-sep 5189 ax-nul 5196 ax-pow 5255 ax-pr 5319 ax-un 7520 ax-inf2 9253 ax-ac2 10074 |
This theorem depends on definitions: df-bi 210 df-an 400 df-or 848 df-3or 1090 df-3an 1091 df-tru 1546 df-fal 1556 df-ex 1788 df-nf 1792 df-sb 2071 df-mo 2539 df-eu 2568 df-clab 2715 df-cleq 2729 df-clel 2816 df-nfc 2886 df-ne 2940 df-ral 3063 df-rex 3064 df-reu 3065 df-rmo 3066 df-rab 3067 df-v 3407 df-sbc 3692 df-csb 3809 df-dif 3866 df-un 3868 df-in 3870 df-ss 3880 df-pss 3882 df-nul 4235 df-if 4437 df-pw 4512 df-sn 4539 df-pr 4541 df-tp 4543 df-op 4545 df-uni 4817 df-int 4857 df-iun 4903 df-br 5051 df-opab 5113 df-mpt 5133 df-tr 5159 df-id 5452 df-eprel 5457 df-po 5465 df-so 5466 df-fr 5506 df-se 5507 df-we 5508 df-xp 5554 df-rel 5555 df-cnv 5556 df-co 5557 df-dm 5558 df-rn 5559 df-res 5560 df-ima 5561 df-pred 6157 df-ord 6213 df-on 6214 df-lim 6215 df-suc 6216 df-iota 6335 df-fun 6379 df-fn 6380 df-f 6381 df-f1 6382 df-fo 6383 df-f1o 6384 df-fv 6385 df-isom 6386 df-riota 7167 df-ov 7213 df-oprab 7214 df-mpo 7215 df-om 7642 df-1st 7758 df-2nd 7759 df-wrecs 8044 df-recs 8105 df-rdg 8143 df-1o 8199 df-er 8388 df-map 8507 df-en 8624 df-dom 8625 df-sdom 8626 df-fin 8627 df-oi 9123 df-card 9552 df-acn 9555 df-ac 9727 |
This theorem is referenced by: sigaclcuni 31795 measvunilem 31889 |
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