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Mirrors > Home > MPE Home > Th. List > ssdomfi | Structured version Visualization version GIF version |
Description: A finite set dominates its subsets, proved without using the Axiom of Power Sets (unlike ssdomg 8943). (Contributed by BTernaryTau, 12-Nov-2024.) |
Ref | Expression |
---|---|
ssdomfi | ⊢ (𝐵 ∈ Fin → (𝐴 ⊆ 𝐵 → 𝐴 ≼ 𝐵)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | f1oi 6823 | . . . . 5 ⊢ ( I ↾ 𝐴):𝐴–1-1-onto→𝐴 | |
2 | f1of1 6784 | . . . . 5 ⊢ (( I ↾ 𝐴):𝐴–1-1-onto→𝐴 → ( I ↾ 𝐴):𝐴–1-1→𝐴) | |
3 | 1, 2 | ax-mp 5 | . . . 4 ⊢ ( I ↾ 𝐴):𝐴–1-1→𝐴 |
4 | f1ss 6745 | . . . 4 ⊢ ((( I ↾ 𝐴):𝐴–1-1→𝐴 ∧ 𝐴 ⊆ 𝐵) → ( I ↾ 𝐴):𝐴–1-1→𝐵) | |
5 | 3, 4 | mpan 689 | . . 3 ⊢ (𝐴 ⊆ 𝐵 → ( I ↾ 𝐴):𝐴–1-1→𝐵) |
6 | f1domfi 9131 | . . 3 ⊢ ((𝐵 ∈ Fin ∧ ( I ↾ 𝐴):𝐴–1-1→𝐵) → 𝐴 ≼ 𝐵) | |
7 | 5, 6 | sylan2 594 | . 2 ⊢ ((𝐵 ∈ Fin ∧ 𝐴 ⊆ 𝐵) → 𝐴 ≼ 𝐵) |
8 | 7 | ex 414 | 1 ⊢ (𝐵 ∈ Fin → (𝐴 ⊆ 𝐵 → 𝐴 ≼ 𝐵)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∈ wcel 2107 ⊆ wss 3911 class class class wbr 5106 I cid 5531 ↾ cres 5636 –1-1→wf1 6494 –1-1-onto→wf1o 6496 ≼ cdom 8884 Fincfn 8886 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1798 ax-4 1812 ax-5 1914 ax-6 1972 ax-7 2012 ax-8 2109 ax-9 2117 ax-10 2138 ax-11 2155 ax-12 2172 ax-ext 2704 ax-sep 5257 ax-nul 5264 ax-pr 5385 ax-un 7673 |
This theorem depends on definitions: df-bi 206 df-an 398 df-or 847 df-3or 1089 df-3an 1090 df-tru 1545 df-fal 1555 df-ex 1783 df-nf 1787 df-sb 2069 df-mo 2535 df-eu 2564 df-clab 2711 df-cleq 2725 df-clel 2811 df-nfc 2886 df-ne 2941 df-ral 3062 df-rex 3071 df-reu 3353 df-rab 3407 df-v 3446 df-sbc 3741 df-dif 3914 df-un 3916 df-in 3918 df-ss 3928 df-pss 3930 df-nul 4284 df-if 4488 df-pw 4563 df-sn 4588 df-pr 4590 df-op 4594 df-uni 4867 df-br 5107 df-opab 5169 df-tr 5224 df-id 5532 df-eprel 5538 df-po 5546 df-so 5547 df-fr 5589 df-we 5591 df-xp 5640 df-rel 5641 df-cnv 5642 df-co 5643 df-dm 5644 df-rn 5645 df-res 5646 df-ima 5647 df-ord 6321 df-on 6322 df-lim 6323 df-suc 6324 df-iota 6449 df-fun 6499 df-fn 6500 df-f 6501 df-f1 6502 df-fo 6503 df-f1o 6504 df-fv 6505 df-om 7804 df-1o 8413 df-en 8887 df-dom 8888 df-fin 8890 |
This theorem is referenced by: php 9157 php2 9158 |
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