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Mirrors > Home > MPE Home > Th. List > infunabs | Structured version Visualization version GIF version |
Description: An infinite set is equinumerous to its union with a smaller one. (Contributed by NM, 28-Sep-2004.) (Revised by Mario Carneiro, 29-Apr-2015.) |
Ref | Expression |
---|---|
infunabs | ⊢ ((𝐴 ∈ dom card ∧ ω ≼ 𝐴 ∧ 𝐵 ≼ 𝐴) → (𝐴 ∪ 𝐵) ≈ 𝐴) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simp1 1137 | . . . 4 ⊢ ((𝐴 ∈ dom card ∧ ω ≼ 𝐴 ∧ 𝐵 ≼ 𝐴) → 𝐴 ∈ dom card) | |
2 | reldom 8895 | . . . . . 6 ⊢ Rel ≼ | |
3 | 2 | brrelex1i 5692 | . . . . 5 ⊢ (𝐵 ≼ 𝐴 → 𝐵 ∈ V) |
4 | 3 | 3ad2ant3 1136 | . . . 4 ⊢ ((𝐴 ∈ dom card ∧ ω ≼ 𝐴 ∧ 𝐵 ≼ 𝐴) → 𝐵 ∈ V) |
5 | undjudom 10111 | . . . 4 ⊢ ((𝐴 ∈ dom card ∧ 𝐵 ∈ V) → (𝐴 ∪ 𝐵) ≼ (𝐴 ⊔ 𝐵)) | |
6 | 1, 4, 5 | syl2anc 585 | . . 3 ⊢ ((𝐴 ∈ dom card ∧ ω ≼ 𝐴 ∧ 𝐵 ≼ 𝐴) → (𝐴 ∪ 𝐵) ≼ (𝐴 ⊔ 𝐵)) |
7 | infdjuabs 10150 | . . 3 ⊢ ((𝐴 ∈ dom card ∧ ω ≼ 𝐴 ∧ 𝐵 ≼ 𝐴) → (𝐴 ⊔ 𝐵) ≈ 𝐴) | |
8 | domentr 8959 | . . 3 ⊢ (((𝐴 ∪ 𝐵) ≼ (𝐴 ⊔ 𝐵) ∧ (𝐴 ⊔ 𝐵) ≈ 𝐴) → (𝐴 ∪ 𝐵) ≼ 𝐴) | |
9 | 6, 7, 8 | syl2anc 585 | . 2 ⊢ ((𝐴 ∈ dom card ∧ ω ≼ 𝐴 ∧ 𝐵 ≼ 𝐴) → (𝐴 ∪ 𝐵) ≼ 𝐴) |
10 | unexg 7687 | . . . 4 ⊢ ((𝐴 ∈ dom card ∧ 𝐵 ∈ V) → (𝐴 ∪ 𝐵) ∈ V) | |
11 | 1, 4, 10 | syl2anc 585 | . . 3 ⊢ ((𝐴 ∈ dom card ∧ ω ≼ 𝐴 ∧ 𝐵 ≼ 𝐴) → (𝐴 ∪ 𝐵) ∈ V) |
12 | ssun1 4136 | . . 3 ⊢ 𝐴 ⊆ (𝐴 ∪ 𝐵) | |
13 | ssdomg 8946 | . . 3 ⊢ ((𝐴 ∪ 𝐵) ∈ V → (𝐴 ⊆ (𝐴 ∪ 𝐵) → 𝐴 ≼ (𝐴 ∪ 𝐵))) | |
14 | 11, 12, 13 | mpisyl 21 | . 2 ⊢ ((𝐴 ∈ dom card ∧ ω ≼ 𝐴 ∧ 𝐵 ≼ 𝐴) → 𝐴 ≼ (𝐴 ∪ 𝐵)) |
15 | sbth 9043 | . 2 ⊢ (((𝐴 ∪ 𝐵) ≼ 𝐴 ∧ 𝐴 ≼ (𝐴 ∪ 𝐵)) → (𝐴 ∪ 𝐵) ≈ 𝐴) | |
16 | 9, 14, 15 | syl2anc 585 | 1 ⊢ ((𝐴 ∈ dom card ∧ ω ≼ 𝐴 ∧ 𝐵 ≼ 𝐴) → (𝐴 ∪ 𝐵) ≈ 𝐴) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ w3a 1088 ∈ wcel 2107 Vcvv 3447 ∪ cun 3912 ⊆ wss 3914 class class class wbr 5109 dom cdm 5637 ωcom 7806 ≈ cen 8886 ≼ cdom 8887 ⊔ cdju 9842 cardccrd 9879 |
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-rep 5246 ax-sep 5260 ax-nul 5267 ax-pow 5324 ax-pr 5388 ax-un 7676 ax-inf2 9585 |
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-rmo 3352 df-reu 3353 df-rab 3407 df-v 3449 df-sbc 3744 df-csb 3860 df-dif 3917 df-un 3919 df-in 3921 df-ss 3931 df-pss 3933 df-nul 4287 df-if 4491 df-pw 4566 df-sn 4591 df-pr 4593 df-op 4597 df-uni 4870 df-int 4912 df-iun 4960 df-br 5110 df-opab 5172 df-mpt 5193 df-tr 5227 df-id 5535 df-eprel 5541 df-po 5549 df-so 5550 df-fr 5592 df-se 5593 df-we 5594 df-xp 5643 df-rel 5644 df-cnv 5645 df-co 5646 df-dm 5647 df-rn 5648 df-res 5649 df-ima 5650 df-pred 6257 df-ord 6324 df-on 6325 df-lim 6326 df-suc 6327 df-iota 6452 df-fun 6502 df-fn 6503 df-f 6504 df-f1 6505 df-fo 6506 df-f1o 6507 df-fv 6508 df-isom 6509 df-riota 7317 df-ov 7364 df-om 7807 df-1st 7925 df-2nd 7926 df-frecs 8216 df-wrecs 8247 df-recs 8321 df-rdg 8360 df-1o 8416 df-2o 8417 df-er 8654 df-en 8890 df-dom 8891 df-sdom 8892 df-fin 8893 df-oi 9454 df-dju 9845 df-card 9883 |
This theorem is referenced by: infunsdom1 10157 infxp 10159 |
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