MPE Home Metamath Proof Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  MPE Home  >  Th. List  >  cfflb Structured version   Visualization version   GIF version

Theorem cfflb 9534
Description: If there is a cofinal map from 𝐵 to 𝐴, then 𝐵 is at least (cf‘𝐴). This theorem and cff1 9533 motivate the picture of (cf‘𝐴) as the greatest lower bound of the domain of cofinal maps into 𝐴. (Contributed by Mario Carneiro, 28-Feb-2013.)
Assertion
Ref Expression
cfflb ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (∃𝑓(𝑓:𝐵𝐴 ∧ ∀𝑧𝐴𝑤𝐵 𝑧 ⊆ (𝑓𝑤)) → (cf‘𝐴) ⊆ 𝐵))
Distinct variable groups:   𝐴,𝑓,𝑤,𝑧   𝐵,𝑓,𝑤,𝑧

Proof of Theorem cfflb
Dummy variables 𝑠 𝑥 𝑦 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 frn 6395 . . . . . . 7 (𝑓:𝐵𝐴 → ran 𝑓𝐴)
21adantr 481 . . . . . 6 ((𝑓:𝐵𝐴 ∧ ∀𝑧𝐴𝑤𝐵 𝑧 ⊆ (𝑓𝑤)) → ran 𝑓𝐴)
3 ffn 6389 . . . . . . . . . . 11 (𝑓:𝐵𝐴𝑓 Fn 𝐵)
4 fnfvelrn 6720 . . . . . . . . . . 11 ((𝑓 Fn 𝐵𝑤𝐵) → (𝑓𝑤) ∈ ran 𝑓)
53, 4sylan 580 . . . . . . . . . 10 ((𝑓:𝐵𝐴𝑤𝐵) → (𝑓𝑤) ∈ ran 𝑓)
6 sseq2 3920 . . . . . . . . . . 11 (𝑠 = (𝑓𝑤) → (𝑧𝑠𝑧 ⊆ (𝑓𝑤)))
76rspcev 3561 . . . . . . . . . 10 (((𝑓𝑤) ∈ ran 𝑓𝑧 ⊆ (𝑓𝑤)) → ∃𝑠 ∈ ran 𝑓 𝑧𝑠)
85, 7sylan 580 . . . . . . . . 9 (((𝑓:𝐵𝐴𝑤𝐵) ∧ 𝑧 ⊆ (𝑓𝑤)) → ∃𝑠 ∈ ran 𝑓 𝑧𝑠)
98rexlimdva2 3252 . . . . . . . 8 (𝑓:𝐵𝐴 → (∃𝑤𝐵 𝑧 ⊆ (𝑓𝑤) → ∃𝑠 ∈ ran 𝑓 𝑧𝑠))
109ralimdv 3147 . . . . . . 7 (𝑓:𝐵𝐴 → (∀𝑧𝐴𝑤𝐵 𝑧 ⊆ (𝑓𝑤) → ∀𝑧𝐴𝑠 ∈ ran 𝑓 𝑧𝑠))
1110imp 407 . . . . . 6 ((𝑓:𝐵𝐴 ∧ ∀𝑧𝐴𝑤𝐵 𝑧 ⊆ (𝑓𝑤)) → ∀𝑧𝐴𝑠 ∈ ran 𝑓 𝑧𝑠)
122, 11jca 512 . . . . 5 ((𝑓:𝐵𝐴 ∧ ∀𝑧𝐴𝑤𝐵 𝑧 ⊆ (𝑓𝑤)) → (ran 𝑓𝐴 ∧ ∀𝑧𝐴𝑠 ∈ ran 𝑓 𝑧𝑠))
13 fvex 6558 . . . . . 6 (card‘ran 𝑓) ∈ V
14 cfval 9522 . . . . . . . . . . 11 (𝐴 ∈ On → (cf‘𝐴) = {𝑥 ∣ ∃𝑦(𝑥 = (card‘𝑦) ∧ (𝑦𝐴 ∧ ∀𝑧𝐴𝑠𝑦 𝑧𝑠))})
1514adantr 481 . . . . . . . . . 10 ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (cf‘𝐴) = {𝑥 ∣ ∃𝑦(𝑥 = (card‘𝑦) ∧ (𝑦𝐴 ∧ ∀𝑧𝐴𝑠𝑦 𝑧𝑠))})
16153ad2ant2 1127 . . . . . . . . 9 ((𝑥 = (card‘ran 𝑓) ∧ (𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ (ran 𝑓𝐴 ∧ ∀𝑧𝐴𝑠 ∈ ran 𝑓 𝑧𝑠)) → (cf‘𝐴) = {𝑥 ∣ ∃𝑦(𝑥 = (card‘𝑦) ∧ (𝑦𝐴 ∧ ∀𝑧𝐴𝑠𝑦 𝑧𝑠))})
17 vex 3443 . . . . . . . . . . . . . 14 𝑓 ∈ V
1817rnex 7480 . . . . . . . . . . . . 13 ran 𝑓 ∈ V
19 fveq2 6545 . . . . . . . . . . . . . . 15 (𝑦 = ran 𝑓 → (card‘𝑦) = (card‘ran 𝑓))
2019eqeq2d 2807 . . . . . . . . . . . . . 14 (𝑦 = ran 𝑓 → (𝑥 = (card‘𝑦) ↔ 𝑥 = (card‘ran 𝑓)))
21 sseq1 3919 . . . . . . . . . . . . . . 15 (𝑦 = ran 𝑓 → (𝑦𝐴 ↔ ran 𝑓𝐴))
22 rexeq 3368 . . . . . . . . . . . . . . . 16 (𝑦 = ran 𝑓 → (∃𝑠𝑦 𝑧𝑠 ↔ ∃𝑠 ∈ ran 𝑓 𝑧𝑠))
2322ralbidv 3166 . . . . . . . . . . . . . . 15 (𝑦 = ran 𝑓 → (∀𝑧𝐴𝑠𝑦 𝑧𝑠 ↔ ∀𝑧𝐴𝑠 ∈ ran 𝑓 𝑧𝑠))
2421, 23anbi12d 630 . . . . . . . . . . . . . 14 (𝑦 = ran 𝑓 → ((𝑦𝐴 ∧ ∀𝑧𝐴𝑠𝑦 𝑧𝑠) ↔ (ran 𝑓𝐴 ∧ ∀𝑧𝐴𝑠 ∈ ran 𝑓 𝑧𝑠)))
2520, 24anbi12d 630 . . . . . . . . . . . . 13 (𝑦 = ran 𝑓 → ((𝑥 = (card‘𝑦) ∧ (𝑦𝐴 ∧ ∀𝑧𝐴𝑠𝑦 𝑧𝑠)) ↔ (𝑥 = (card‘ran 𝑓) ∧ (ran 𝑓𝐴 ∧ ∀𝑧𝐴𝑠 ∈ ran 𝑓 𝑧𝑠))))
2618, 25spcev 3551 . . . . . . . . . . . 12 ((𝑥 = (card‘ran 𝑓) ∧ (ran 𝑓𝐴 ∧ ∀𝑧𝐴𝑠 ∈ ran 𝑓 𝑧𝑠)) → ∃𝑦(𝑥 = (card‘𝑦) ∧ (𝑦𝐴 ∧ ∀𝑧𝐴𝑠𝑦 𝑧𝑠)))
27 abid 2781 . . . . . . . . . . . 12 (𝑥 ∈ {𝑥 ∣ ∃𝑦(𝑥 = (card‘𝑦) ∧ (𝑦𝐴 ∧ ∀𝑧𝐴𝑠𝑦 𝑧𝑠))} ↔ ∃𝑦(𝑥 = (card‘𝑦) ∧ (𝑦𝐴 ∧ ∀𝑧𝐴𝑠𝑦 𝑧𝑠)))
2826, 27sylibr 235 . . . . . . . . . . 11 ((𝑥 = (card‘ran 𝑓) ∧ (ran 𝑓𝐴 ∧ ∀𝑧𝐴𝑠 ∈ ran 𝑓 𝑧𝑠)) → 𝑥 ∈ {𝑥 ∣ ∃𝑦(𝑥 = (card‘𝑦) ∧ (𝑦𝐴 ∧ ∀𝑧𝐴𝑠𝑦 𝑧𝑠))})
29 intss1 4803 . . . . . . . . . . 11 (𝑥 ∈ {𝑥 ∣ ∃𝑦(𝑥 = (card‘𝑦) ∧ (𝑦𝐴 ∧ ∀𝑧𝐴𝑠𝑦 𝑧𝑠))} → {𝑥 ∣ ∃𝑦(𝑥 = (card‘𝑦) ∧ (𝑦𝐴 ∧ ∀𝑧𝐴𝑠𝑦 𝑧𝑠))} ⊆ 𝑥)
3028, 29syl 17 . . . . . . . . . 10 ((𝑥 = (card‘ran 𝑓) ∧ (ran 𝑓𝐴 ∧ ∀𝑧𝐴𝑠 ∈ ran 𝑓 𝑧𝑠)) → {𝑥 ∣ ∃𝑦(𝑥 = (card‘𝑦) ∧ (𝑦𝐴 ∧ ∀𝑧𝐴𝑠𝑦 𝑧𝑠))} ⊆ 𝑥)
31303adant2 1124 . . . . . . . . 9 ((𝑥 = (card‘ran 𝑓) ∧ (𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ (ran 𝑓𝐴 ∧ ∀𝑧𝐴𝑠 ∈ ran 𝑓 𝑧𝑠)) → {𝑥 ∣ ∃𝑦(𝑥 = (card‘𝑦) ∧ (𝑦𝐴 ∧ ∀𝑧𝐴𝑠𝑦 𝑧𝑠))} ⊆ 𝑥)
3216, 31eqsstrd 3932 . . . . . . . 8 ((𝑥 = (card‘ran 𝑓) ∧ (𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ (ran 𝑓𝐴 ∧ ∀𝑧𝐴𝑠 ∈ ran 𝑓 𝑧𝑠)) → (cf‘𝐴) ⊆ 𝑥)
33323expib 1115 . . . . . . 7 (𝑥 = (card‘ran 𝑓) → (((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ (ran 𝑓𝐴 ∧ ∀𝑧𝐴𝑠 ∈ ran 𝑓 𝑧𝑠)) → (cf‘𝐴) ⊆ 𝑥))
34 sseq2 3920 . . . . . . 7 (𝑥 = (card‘ran 𝑓) → ((cf‘𝐴) ⊆ 𝑥 ↔ (cf‘𝐴) ⊆ (card‘ran 𝑓)))
3533, 34sylibd 240 . . . . . 6 (𝑥 = (card‘ran 𝑓) → (((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ (ran 𝑓𝐴 ∧ ∀𝑧𝐴𝑠 ∈ ran 𝑓 𝑧𝑠)) → (cf‘𝐴) ⊆ (card‘ran 𝑓)))
3613, 35vtocle 3529 . . . . 5 (((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ (ran 𝑓𝐴 ∧ ∀𝑧𝐴𝑠 ∈ ran 𝑓 𝑧𝑠)) → (cf‘𝐴) ⊆ (card‘ran 𝑓))
3712, 36sylan2 592 . . . 4 (((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ (𝑓:𝐵𝐴 ∧ ∀𝑧𝐴𝑤𝐵 𝑧 ⊆ (𝑓𝑤))) → (cf‘𝐴) ⊆ (card‘ran 𝑓))
38 cardidm 9241 . . . . . . 7 (card‘(card‘ran 𝑓)) = (card‘ran 𝑓)
39 onss 7368 . . . . . . . . . . . . . 14 (𝐴 ∈ On → 𝐴 ⊆ On)
401, 39sylan9ssr 3909 . . . . . . . . . . . . 13 ((𝐴 ∈ On ∧ 𝑓:𝐵𝐴) → ran 𝑓 ⊆ On)
41403adant2 1124 . . . . . . . . . . . 12 ((𝐴 ∈ On ∧ 𝐵 ∈ On ∧ 𝑓:𝐵𝐴) → ran 𝑓 ⊆ On)
42 onssnum 9319 . . . . . . . . . . . 12 ((ran 𝑓 ∈ V ∧ ran 𝑓 ⊆ On) → ran 𝑓 ∈ dom card)
4318, 41, 42sylancr 587 . . . . . . . . . . 11 ((𝐴 ∈ On ∧ 𝐵 ∈ On ∧ 𝑓:𝐵𝐴) → ran 𝑓 ∈ dom card)
44 cardid2 9235 . . . . . . . . . . 11 (ran 𝑓 ∈ dom card → (card‘ran 𝑓) ≈ ran 𝑓)
4543, 44syl 17 . . . . . . . . . 10 ((𝐴 ∈ On ∧ 𝐵 ∈ On ∧ 𝑓:𝐵𝐴) → (card‘ran 𝑓) ≈ ran 𝑓)
46 onenon 9231 . . . . . . . . . . . . 13 (𝐵 ∈ On → 𝐵 ∈ dom card)
47 dffn4 6471 . . . . . . . . . . . . . 14 (𝑓 Fn 𝐵𝑓:𝐵onto→ran 𝑓)
483, 47sylib 219 . . . . . . . . . . . . 13 (𝑓:𝐵𝐴𝑓:𝐵onto→ran 𝑓)
49 fodomnum 9336 . . . . . . . . . . . . 13 (𝐵 ∈ dom card → (𝑓:𝐵onto→ran 𝑓 → ran 𝑓𝐵))
5046, 48, 49syl2im 40 . . . . . . . . . . . 12 (𝐵 ∈ On → (𝑓:𝐵𝐴 → ran 𝑓𝐵))
5150imp 407 . . . . . . . . . . 11 ((𝐵 ∈ On ∧ 𝑓:𝐵𝐴) → ran 𝑓𝐵)
52513adant1 1123 . . . . . . . . . 10 ((𝐴 ∈ On ∧ 𝐵 ∈ On ∧ 𝑓:𝐵𝐴) → ran 𝑓𝐵)
53 endomtr 8422 . . . . . . . . . 10 (((card‘ran 𝑓) ≈ ran 𝑓 ∧ ran 𝑓𝐵) → (card‘ran 𝑓) ≼ 𝐵)
5445, 52, 53syl2anc 584 . . . . . . . . 9 ((𝐴 ∈ On ∧ 𝐵 ∈ On ∧ 𝑓:𝐵𝐴) → (card‘ran 𝑓) ≼ 𝐵)
55 cardon 9226 . . . . . . . . . . . 12 (card‘ran 𝑓) ∈ On
56 onenon 9231 . . . . . . . . . . . 12 ((card‘ran 𝑓) ∈ On → (card‘ran 𝑓) ∈ dom card)
5755, 56ax-mp 5 . . . . . . . . . . 11 (card‘ran 𝑓) ∈ dom card
58 carddom2 9259 . . . . . . . . . . 11 (((card‘ran 𝑓) ∈ dom card ∧ 𝐵 ∈ dom card) → ((card‘(card‘ran 𝑓)) ⊆ (card‘𝐵) ↔ (card‘ran 𝑓) ≼ 𝐵))
5957, 46, 58sylancr 587 . . . . . . . . . 10 (𝐵 ∈ On → ((card‘(card‘ran 𝑓)) ⊆ (card‘𝐵) ↔ (card‘ran 𝑓) ≼ 𝐵))
60593ad2ant2 1127 . . . . . . . . 9 ((𝐴 ∈ On ∧ 𝐵 ∈ On ∧ 𝑓:𝐵𝐴) → ((card‘(card‘ran 𝑓)) ⊆ (card‘𝐵) ↔ (card‘ran 𝑓) ≼ 𝐵))
6154, 60mpbird 258 . . . . . . . 8 ((𝐴 ∈ On ∧ 𝐵 ∈ On ∧ 𝑓:𝐵𝐴) → (card‘(card‘ran 𝑓)) ⊆ (card‘𝐵))
62 cardonle 9239 . . . . . . . . 9 (𝐵 ∈ On → (card‘𝐵) ⊆ 𝐵)
63623ad2ant2 1127 . . . . . . . 8 ((𝐴 ∈ On ∧ 𝐵 ∈ On ∧ 𝑓:𝐵𝐴) → (card‘𝐵) ⊆ 𝐵)
6461, 63sstrd 3905 . . . . . . 7 ((𝐴 ∈ On ∧ 𝐵 ∈ On ∧ 𝑓:𝐵𝐴) → (card‘(card‘ran 𝑓)) ⊆ 𝐵)
6538, 64eqsstrrid 3943 . . . . . 6 ((𝐴 ∈ On ∧ 𝐵 ∈ On ∧ 𝑓:𝐵𝐴) → (card‘ran 𝑓) ⊆ 𝐵)
66653expa 1111 . . . . 5 (((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ 𝑓:𝐵𝐴) → (card‘ran 𝑓) ⊆ 𝐵)
6766adantrr 713 . . . 4 (((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ (𝑓:𝐵𝐴 ∧ ∀𝑧𝐴𝑤𝐵 𝑧 ⊆ (𝑓𝑤))) → (card‘ran 𝑓) ⊆ 𝐵)
6837, 67sstrd 3905 . . 3 (((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ (𝑓:𝐵𝐴 ∧ ∀𝑧𝐴𝑤𝐵 𝑧 ⊆ (𝑓𝑤))) → (cf‘𝐴) ⊆ 𝐵)
6968ex 413 . 2 ((𝐴 ∈ On ∧ 𝐵 ∈ On) → ((𝑓:𝐵𝐴 ∧ ∀𝑧𝐴𝑤𝐵 𝑧 ⊆ (𝑓𝑤)) → (cf‘𝐴) ⊆ 𝐵))
7069exlimdv 1915 1 ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (∃𝑓(𝑓:𝐵𝐴 ∧ ∀𝑧𝐴𝑤𝐵 𝑧 ⊆ (𝑓𝑤)) → (cf‘𝐴) ⊆ 𝐵))
Colors of variables: wff setvar class
Syntax hints:  wi 4  wb 207  wa 396  w3a 1080   = wceq 1525  wex 1765  wcel 2083  {cab 2777  wral 3107  wrex 3108  Vcvv 3440  wss 3865   cint 4788   class class class wbr 4968  dom cdm 5450  ran crn 5451  Oncon0 6073   Fn wfn 6227  wf 6228  ontowfo 6230  cfv 6232  cen 8361  cdom 8362  cardccrd 9217  cfccf 9219
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1781  ax-4 1795  ax-5 1892  ax-6 1951  ax-7 1996  ax-8 2085  ax-9 2093  ax-10 2114  ax-11 2128  ax-12 2143  ax-13 2346  ax-ext 2771  ax-rep 5088  ax-sep 5101  ax-nul 5108  ax-pow 5164  ax-pr 5228  ax-un 7326
This theorem depends on definitions:  df-bi 208  df-an 397  df-or 843  df-3or 1081  df-3an 1082  df-tru 1528  df-ex 1766  df-nf 1770  df-sb 2045  df-mo 2578  df-eu 2614  df-clab 2778  df-cleq 2790  df-clel 2865  df-nfc 2937  df-ne 2987  df-ral 3112  df-rex 3113  df-reu 3114  df-rmo 3115  df-rab 3116  df-v 3442  df-sbc 3712  df-csb 3818  df-dif 3868  df-un 3870  df-in 3872  df-ss 3880  df-pss 3882  df-nul 4218  df-if 4388  df-pw 4461  df-sn 4479  df-pr 4481  df-tp 4483  df-op 4485  df-uni 4752  df-int 4789  df-iun 4833  df-br 4969  df-opab 5031  df-mpt 5048  df-tr 5071  df-id 5355  df-eprel 5360  df-po 5369  df-so 5370  df-fr 5409  df-se 5410  df-we 5411  df-xp 5456  df-rel 5457  df-cnv 5458  df-co 5459  df-dm 5460  df-rn 5461  df-res 5462  df-ima 5463  df-pred 6030  df-ord 6076  df-on 6077  df-suc 6079  df-iota 6196  df-fun 6234  df-fn 6235  df-f 6236  df-f1 6237  df-fo 6238  df-f1o 6239  df-fv 6240  df-isom 6241  df-riota 6984  df-ov 7026  df-oprab 7027  df-mpo 7028  df-1st 7552  df-2nd 7553  df-wrecs 7805  df-recs 7867  df-er 8146  df-map 8265  df-en 8365  df-dom 8366  df-sdom 8367  df-card 9221  df-cf 9223  df-acn 9224
This theorem is referenced by:  cfsmolem  9545  cfcoflem  9547  cfcof  9549  inar1  10050
  Copyright terms: Public domain W3C validator