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Mirrors > Home > MPE Home > Th. List > f1domg | Structured version Visualization version GIF version |
Description: The domain of a one-to-one function is dominated by its codomain. (Contributed by NM, 4-Sep-2004.) |
Ref | Expression |
---|---|
f1domg | ⊢ (𝐵 ∈ 𝐶 → (𝐹:𝐴–1-1→𝐵 → 𝐴 ≼ 𝐵)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | f1f 6443 | . . . . 5 ⊢ (𝐹:𝐴–1-1→𝐵 → 𝐹:𝐴⟶𝐵) | |
2 | f1dmex 7514 | . . . . 5 ⊢ ((𝐹:𝐴–1-1→𝐵 ∧ 𝐵 ∈ 𝐶) → 𝐴 ∈ V) | |
3 | fex 6855 | . . . . 5 ⊢ ((𝐹:𝐴⟶𝐵 ∧ 𝐴 ∈ V) → 𝐹 ∈ V) | |
4 | 1, 2, 3 | syl2an2r 681 | . . . 4 ⊢ ((𝐹:𝐴–1-1→𝐵 ∧ 𝐵 ∈ 𝐶) → 𝐹 ∈ V) |
5 | 4 | expcom 414 | . . 3 ⊢ (𝐵 ∈ 𝐶 → (𝐹:𝐴–1-1→𝐵 → 𝐹 ∈ V)) |
6 | f1eq1 6438 | . . . 4 ⊢ (𝑓 = 𝐹 → (𝑓:𝐴–1-1→𝐵 ↔ 𝐹:𝐴–1-1→𝐵)) | |
7 | 6 | spcegv 3540 | . . 3 ⊢ (𝐹 ∈ V → (𝐹:𝐴–1-1→𝐵 → ∃𝑓 𝑓:𝐴–1-1→𝐵)) |
8 | 5, 7 | syli 39 | . 2 ⊢ (𝐵 ∈ 𝐶 → (𝐹:𝐴–1-1→𝐵 → ∃𝑓 𝑓:𝐴–1-1→𝐵)) |
9 | brdomg 8367 | . 2 ⊢ (𝐵 ∈ 𝐶 → (𝐴 ≼ 𝐵 ↔ ∃𝑓 𝑓:𝐴–1-1→𝐵)) | |
10 | 8, 9 | sylibrd 260 | 1 ⊢ (𝐵 ∈ 𝐶 → (𝐹:𝐴–1-1→𝐵 → 𝐴 ≼ 𝐵)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∃wex 1761 ∈ wcel 2081 Vcvv 3437 class class class wbr 4962 ⟶wf 6221 –1-1→wf1 6222 ≼ cdom 8355 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1777 ax-4 1791 ax-5 1888 ax-6 1947 ax-7 1992 ax-8 2083 ax-9 2091 ax-10 2112 ax-11 2126 ax-12 2141 ax-13 2344 ax-ext 2769 ax-rep 5081 ax-sep 5094 ax-nul 5101 ax-pr 5221 ax-un 7319 |
This theorem depends on definitions: df-bi 208 df-an 397 df-or 843 df-3an 1082 df-tru 1525 df-ex 1762 df-nf 1766 df-sb 2043 df-mo 2576 df-eu 2612 df-clab 2776 df-cleq 2788 df-clel 2863 df-nfc 2935 df-ne 2985 df-ral 3110 df-rex 3111 df-reu 3112 df-rab 3114 df-v 3439 df-sbc 3707 df-csb 3812 df-dif 3862 df-un 3864 df-in 3866 df-ss 3874 df-nul 4212 df-if 4382 df-sn 4473 df-pr 4475 df-op 4479 df-uni 4746 df-iun 4827 df-br 4963 df-opab 5025 df-mpt 5042 df-id 5348 df-xp 5449 df-rel 5450 df-cnv 5451 df-co 5452 df-dm 5453 df-rn 5454 df-res 5455 df-ima 5456 df-iota 6189 df-fun 6227 df-fn 6228 df-f 6229 df-f1 6230 df-fo 6231 df-f1o 6232 df-fv 6233 df-dom 8359 |
This theorem is referenced by: f1dom 8379 dom2d 8398 fseqen 9299 infpssrlem5 9575 hashf1 13663 vdwlem12 16157 2ndcdisj 21748 ovolicc2lem4 23804 basellem4 25343 usgriedgleord 26693 uspgredgleord 26697 |
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