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Theorem subctctexmid 14720
Description: If every subcountable set is countable and Markov's principle holds, excluded middle follows. Proposition 2.6 of [BauerSwan], p. 14:4. The proof is taken from that paper. (Contributed by Jim Kingdon, 29-Nov-2023.)
Hypotheses
Ref Expression
subctctexmid.x (πœ‘ β†’ βˆ€π‘₯(βˆƒπ‘ (𝑠 βŠ† Ο‰ ∧ βˆƒπ‘“ 𝑓:𝑠–ontoβ†’π‘₯) β†’ βˆƒπ‘” 𝑔:ω–ontoβ†’(π‘₯ βŠ” 1o)))
subctctexmid.mk (πœ‘ β†’ Ο‰ ∈ Markov)
Assertion
Ref Expression
subctctexmid (πœ‘ β†’ EXMID)
Distinct variable groups:   𝑓,𝑠,π‘₯   πœ‘,𝑔   π‘₯,𝑔
Allowed substitution hints:   πœ‘(π‘₯,𝑓,𝑠)

Proof of Theorem subctctexmid
Dummy variables 𝑦 𝑧 β„Ž 𝑛 𝑀 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 subctctexmid.x . . . . 5 (πœ‘ β†’ βˆ€π‘₯(βˆƒπ‘ (𝑠 βŠ† Ο‰ ∧ βˆƒπ‘“ 𝑓:𝑠–ontoβ†’π‘₯) β†’ βˆƒπ‘” 𝑔:ω–ontoβ†’(π‘₯ βŠ” 1o)))
2 omex 4592 . . . . . . . 8 Ο‰ ∈ V
32rabex 4147 . . . . . . 7 {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} ∈ V
43a1i 9 . . . . . 6 (πœ‘ β†’ {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} ∈ V)
5 ssrab2 3240 . . . . . . 7 {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ† Ο‰
6 f1oi 5499 . . . . . . . . 9 ( I β†Ύ {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}):{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}–1-1-ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}
7 f1ofo 5468 . . . . . . . . 9 (( I β†Ύ {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}):{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}–1-1-ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} β†’ ( I β†Ύ {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}):{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}})
86, 7ax-mp 5 . . . . . . . 8 ( I β†Ύ {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}):{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}
9 resiexg 4952 . . . . . . . . . 10 ({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} ∈ V β†’ ( I β†Ύ {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}) ∈ V)
103, 9ax-mp 5 . . . . . . . . 9 ( I β†Ύ {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}) ∈ V
11 foeq1 5434 . . . . . . . . 9 (𝑓 = ( I β†Ύ {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}) β†’ (𝑓:{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} ↔ ( I β†Ύ {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}):{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}))
1210, 11spcev 2832 . . . . . . . 8 (( I β†Ύ {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}):{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} β†’ βˆƒπ‘“ 𝑓:{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}})
138, 12ax-mp 5 . . . . . . 7 βˆƒπ‘“ 𝑓:{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}
145, 13pm3.2i 272 . . . . . 6 ({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ† Ο‰ ∧ βˆƒπ‘“ 𝑓:{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}})
15 sseq1 3178 . . . . . . . 8 (𝑠 = {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} β†’ (𝑠 βŠ† Ο‰ ↔ {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ† Ο‰))
16 foeq2 5435 . . . . . . . . 9 (𝑠 = {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} β†’ (𝑓:𝑠–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} ↔ 𝑓:{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}))
1716exbidv 1825 . . . . . . . 8 (𝑠 = {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} β†’ (βˆƒπ‘“ 𝑓:𝑠–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} ↔ βˆƒπ‘“ 𝑓:{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}))
1815, 17anbi12d 473 . . . . . . 7 (𝑠 = {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} β†’ ((𝑠 βŠ† Ο‰ ∧ βˆƒπ‘“ 𝑓:𝑠–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}) ↔ ({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ† Ο‰ ∧ βˆƒπ‘“ 𝑓:{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}})))
1918spcegv 2825 . . . . . 6 ({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} ∈ V β†’ (({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ† Ο‰ ∧ βˆƒπ‘“ 𝑓:{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}) β†’ βˆƒπ‘ (𝑠 βŠ† Ο‰ ∧ βˆƒπ‘“ 𝑓:𝑠–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}})))
204, 14, 19mpisyl 1446 . . . . 5 (πœ‘ β†’ βˆƒπ‘ (𝑠 βŠ† Ο‰ ∧ βˆƒπ‘“ 𝑓:𝑠–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}))
21 foeq3 5436 . . . . . . . . . 10 (π‘₯ = {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} β†’ (𝑓:𝑠–ontoβ†’π‘₯ ↔ 𝑓:𝑠–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}))
2221exbidv 1825 . . . . . . . . 9 (π‘₯ = {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} β†’ (βˆƒπ‘“ 𝑓:𝑠–ontoβ†’π‘₯ ↔ βˆƒπ‘“ 𝑓:𝑠–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}))
2322anbi2d 464 . . . . . . . 8 (π‘₯ = {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} β†’ ((𝑠 βŠ† Ο‰ ∧ βˆƒπ‘“ 𝑓:𝑠–ontoβ†’π‘₯) ↔ (𝑠 βŠ† Ο‰ ∧ βˆƒπ‘“ 𝑓:𝑠–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}})))
2423exbidv 1825 . . . . . . 7 (π‘₯ = {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} β†’ (βˆƒπ‘ (𝑠 βŠ† Ο‰ ∧ βˆƒπ‘“ 𝑓:𝑠–ontoβ†’π‘₯) ↔ βˆƒπ‘ (𝑠 βŠ† Ο‰ ∧ βˆƒπ‘“ 𝑓:𝑠–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}})))
25 djueq1 7038 . . . . . . . . 9 (π‘₯ = {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} β†’ (π‘₯ βŠ” 1o) = ({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o))
26 foeq3 5436 . . . . . . . . 9 ((π‘₯ βŠ” 1o) = ({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o) β†’ (𝑔:ω–ontoβ†’(π‘₯ βŠ” 1o) ↔ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)))
2725, 26syl 14 . . . . . . . 8 (π‘₯ = {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} β†’ (𝑔:ω–ontoβ†’(π‘₯ βŠ” 1o) ↔ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)))
2827exbidv 1825 . . . . . . 7 (π‘₯ = {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} β†’ (βˆƒπ‘” 𝑔:ω–ontoβ†’(π‘₯ βŠ” 1o) ↔ βˆƒπ‘” 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)))
2924, 28imbi12d 234 . . . . . 6 (π‘₯ = {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} β†’ ((βˆƒπ‘ (𝑠 βŠ† Ο‰ ∧ βˆƒπ‘“ 𝑓:𝑠–ontoβ†’π‘₯) β†’ βˆƒπ‘” 𝑔:ω–ontoβ†’(π‘₯ βŠ” 1o)) ↔ (βˆƒπ‘ (𝑠 βŠ† Ο‰ ∧ βˆƒπ‘“ 𝑓:𝑠–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}) β†’ βˆƒπ‘” 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o))))
303, 29spcv 2831 . . . . 5 (βˆ€π‘₯(βˆƒπ‘ (𝑠 βŠ† Ο‰ ∧ βˆƒπ‘“ 𝑓:𝑠–ontoβ†’π‘₯) β†’ βˆƒπ‘” 𝑔:ω–ontoβ†’(π‘₯ βŠ” 1o)) β†’ (βˆƒπ‘ (𝑠 βŠ† Ο‰ ∧ βˆƒπ‘“ 𝑓:𝑠–ontoβ†’{𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}}) β†’ βˆƒπ‘” 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)))
311, 20, 30sylc 62 . . . 4 (πœ‘ β†’ βˆƒπ‘” 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o))
32 fveq1 5514 . . . . . . . . . . . 12 (β„Ž = (𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…)) β†’ (β„Žβ€˜π‘›) = ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›))
3332eqeq1d 2186 . . . . . . . . . . 11 (β„Ž = (𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…)) β†’ ((β„Žβ€˜π‘›) = 1o ↔ ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = 1o))
3433rexbidv 2478 . . . . . . . . . 10 (β„Ž = (𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…)) β†’ (βˆƒπ‘› ∈ Ο‰ (β„Žβ€˜π‘›) = 1o ↔ βˆƒπ‘› ∈ Ο‰ ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = 1o))
3534notbid 667 . . . . . . . . 9 (β„Ž = (𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…)) β†’ (Β¬ βˆƒπ‘› ∈ Ο‰ (β„Žβ€˜π‘›) = 1o ↔ Β¬ βˆƒπ‘› ∈ Ο‰ ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = 1o))
3635notbid 667 . . . . . . . 8 (β„Ž = (𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…)) β†’ (Β¬ Β¬ βˆƒπ‘› ∈ Ο‰ (β„Žβ€˜π‘›) = 1o ↔ Β¬ Β¬ βˆƒπ‘› ∈ Ο‰ ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = 1o))
3736, 34imbi12d 234 . . . . . . 7 (β„Ž = (𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…)) β†’ ((Β¬ Β¬ βˆƒπ‘› ∈ Ο‰ (β„Žβ€˜π‘›) = 1o β†’ βˆƒπ‘› ∈ Ο‰ (β„Žβ€˜π‘›) = 1o) ↔ (Β¬ Β¬ βˆƒπ‘› ∈ Ο‰ ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = 1o β†’ βˆƒπ‘› ∈ Ο‰ ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = 1o)))
38 subctctexmid.mk . . . . . . . . 9 (πœ‘ β†’ Ο‰ ∈ Markov)
39 ismkvnex 7152 . . . . . . . . . 10 (Ο‰ ∈ Markov β†’ (Ο‰ ∈ Markov ↔ βˆ€β„Ž ∈ (2o β†‘π‘š Ο‰)(Β¬ Β¬ βˆƒπ‘› ∈ Ο‰ (β„Žβ€˜π‘›) = 1o β†’ βˆƒπ‘› ∈ Ο‰ (β„Žβ€˜π‘›) = 1o)))
4038, 39syl 14 . . . . . . . . 9 (πœ‘ β†’ (Ο‰ ∈ Markov ↔ βˆ€β„Ž ∈ (2o β†‘π‘š Ο‰)(Β¬ Β¬ βˆƒπ‘› ∈ Ο‰ (β„Žβ€˜π‘›) = 1o β†’ βˆƒπ‘› ∈ Ο‰ (β„Žβ€˜π‘›) = 1o)))
4138, 40mpbid 147 . . . . . . . 8 (πœ‘ β†’ βˆ€β„Ž ∈ (2o β†‘π‘š Ο‰)(Β¬ Β¬ βˆƒπ‘› ∈ Ο‰ (β„Žβ€˜π‘›) = 1o β†’ βˆƒπ‘› ∈ Ο‰ (β„Žβ€˜π‘›) = 1o))
4241adantr 276 . . . . . . 7 ((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) β†’ βˆ€β„Ž ∈ (2o β†‘π‘š Ο‰)(Β¬ Β¬ βˆƒπ‘› ∈ Ο‰ (β„Žβ€˜π‘›) = 1o β†’ βˆƒπ‘› ∈ Ο‰ (β„Žβ€˜π‘›) = 1o))
43 1lt2o 6442 . . . . . . . . . . . 12 1o ∈ 2o
4443a1i 9 . . . . . . . . . . 11 ((((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) ∧ (1st β€˜(π‘”β€˜π‘›)) = βˆ…) β†’ 1o ∈ 2o)
45 0lt2o 6441 . . . . . . . . . . . 12 βˆ… ∈ 2o
4645a1i 9 . . . . . . . . . . 11 ((((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) ∧ Β¬ (1st β€˜(π‘”β€˜π‘›)) = βˆ…) β†’ βˆ… ∈ 2o)
47 simplr 528 . . . . . . . . . . . . . . 15 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) β†’ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o))
48 fof 5438 . . . . . . . . . . . . . . 15 (𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o) β†’ 𝑔:Ο‰βŸΆ({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o))
4947, 48syl 14 . . . . . . . . . . . . . 14 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) β†’ 𝑔:Ο‰βŸΆ({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o))
50 simpr 110 . . . . . . . . . . . . . 14 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) β†’ 𝑛 ∈ Ο‰)
5149, 50ffvelcdmd 5652 . . . . . . . . . . . . 13 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) β†’ (π‘”β€˜π‘›) ∈ ({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o))
52 eldju1st 7069 . . . . . . . . . . . . 13 ((π‘”β€˜π‘›) ∈ ({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o) β†’ ((1st β€˜(π‘”β€˜π‘›)) = βˆ… ∨ (1st β€˜(π‘”β€˜π‘›)) = 1o))
5351, 52syl 14 . . . . . . . . . . . 12 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) β†’ ((1st β€˜(π‘”β€˜π‘›)) = βˆ… ∨ (1st β€˜(π‘”β€˜π‘›)) = 1o))
54 1n0 6432 . . . . . . . . . . . . . . . 16 1o β‰  βˆ…
5554neii 2349 . . . . . . . . . . . . . . 15 Β¬ 1o = βˆ…
56 eqeq1 2184 . . . . . . . . . . . . . . 15 ((1st β€˜(π‘”β€˜π‘›)) = 1o β†’ ((1st β€˜(π‘”β€˜π‘›)) = βˆ… ↔ 1o = βˆ…))
5755, 56mtbiri 675 . . . . . . . . . . . . . 14 ((1st β€˜(π‘”β€˜π‘›)) = 1o β†’ Β¬ (1st β€˜(π‘”β€˜π‘›)) = βˆ…)
5857orim2i 761 . . . . . . . . . . . . 13 (((1st β€˜(π‘”β€˜π‘›)) = βˆ… ∨ (1st β€˜(π‘”β€˜π‘›)) = 1o) β†’ ((1st β€˜(π‘”β€˜π‘›)) = βˆ… ∨ Β¬ (1st β€˜(π‘”β€˜π‘›)) = βˆ…))
59 df-dc 835 . . . . . . . . . . . . 13 (DECID (1st β€˜(π‘”β€˜π‘›)) = βˆ… ↔ ((1st β€˜(π‘”β€˜π‘›)) = βˆ… ∨ Β¬ (1st β€˜(π‘”β€˜π‘›)) = βˆ…))
6058, 59sylibr 134 . . . . . . . . . . . 12 (((1st β€˜(π‘”β€˜π‘›)) = βˆ… ∨ (1st β€˜(π‘”β€˜π‘›)) = 1o) β†’ DECID (1st β€˜(π‘”β€˜π‘›)) = βˆ…)
6153, 60syl 14 . . . . . . . . . . 11 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) β†’ DECID (1st β€˜(π‘”β€˜π‘›)) = βˆ…)
6244, 46, 61ifcldadc 3563 . . . . . . . . . 10 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) β†’ if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) ∈ 2o)
6362fmpttd 5671 . . . . . . . . 9 ((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) β†’ (𝑛 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…)):Ο‰βŸΆ2o)
64 2fveq3 5520 . . . . . . . . . . . . . 14 (𝑀 = 𝑛 β†’ (1st β€˜(π‘”β€˜π‘€)) = (1st β€˜(π‘”β€˜π‘›)))
6564eqeq1d 2186 . . . . . . . . . . . . 13 (𝑀 = 𝑛 β†’ ((1st β€˜(π‘”β€˜π‘€)) = βˆ… ↔ (1st β€˜(π‘”β€˜π‘›)) = βˆ…))
6665ifbid 3555 . . . . . . . . . . . 12 (𝑀 = 𝑛 β†’ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…) = if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…))
67 eqcom 2179 . . . . . . . . . . . 12 (𝑀 = 𝑛 ↔ 𝑛 = 𝑀)
68 eqcom 2179 . . . . . . . . . . . 12 (if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…) = if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) ↔ if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) = if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))
6966, 67, 683imtr3i 200 . . . . . . . . . . 11 (𝑛 = 𝑀 β†’ if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) = if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))
7069cbvmptv 4099 . . . . . . . . . 10 (𝑛 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…)) = (𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))
7170feq1i 5358 . . . . . . . . 9 ((𝑛 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…)):Ο‰βŸΆ2o ↔ (𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…)):Ο‰βŸΆ2o)
7263, 71sylib 122 . . . . . . . 8 ((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) β†’ (𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…)):Ο‰βŸΆ2o)
73 2onn 6521 . . . . . . . . . 10 2o ∈ Ο‰
7473elexi 2749 . . . . . . . . 9 2o ∈ V
7574, 2elmap 6676 . . . . . . . 8 ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…)) ∈ (2o β†‘π‘š Ο‰) ↔ (𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…)):Ο‰βŸΆ2o)
7672, 75sylibr 134 . . . . . . 7 ((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) β†’ (𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…)) ∈ (2o β†‘π‘š Ο‰))
7737, 42, 76rspcdva 2846 . . . . . 6 ((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) β†’ (Β¬ Β¬ βˆƒπ‘› ∈ Ο‰ ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = 1o β†’ βˆƒπ‘› ∈ Ο‰ ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = 1o))
78 eqid 2177 . . . . . . . . . . . . 13 (𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…)) = (𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))
7978, 66, 50, 62fvmptd3 5609 . . . . . . . . . . . 12 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) β†’ ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…))
8079eqeq1d 2186 . . . . . . . . . . 11 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) β†’ (((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = 1o ↔ if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) = 1o))
8151adantr 276 . . . . . . . . . . . . . . 15 ((((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) ∧ if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) = 1o) β†’ (π‘”β€˜π‘›) ∈ ({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o))
82 simpr 110 . . . . . . . . . . . . . . . . 17 ((((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) ∧ if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) = 1o) β†’ if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) = 1o)
8382eqcomd 2183 . . . . . . . . . . . . . . . 16 ((((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) ∧ if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) = 1o) β†’ 1o = if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…))
84 eqifdc 3569 . . . . . . . . . . . . . . . . . . 19 (DECID (1st β€˜(π‘”β€˜π‘›)) = βˆ… β†’ (1o = if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) ↔ (((1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = 1o) ∨ (Β¬ (1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = βˆ…))))
8561, 84syl 14 . . . . . . . . . . . . . . . . . 18 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) β†’ (1o = if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) ↔ (((1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = 1o) ∨ (Β¬ (1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = βˆ…))))
86 eqid 2177 . . . . . . . . . . . . . . . . . . 19 1o = 1o
87 orcom 728 . . . . . . . . . . . . . . . . . . . 20 ((((1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = 1o) ∨ (Β¬ (1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = βˆ…)) ↔ ((Β¬ (1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = βˆ…) ∨ ((1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = 1o)))
8855intnan 929 . . . . . . . . . . . . . . . . . . . . 21 Β¬ (Β¬ (1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = βˆ…)
89 biorf 744 . . . . . . . . . . . . . . . . . . . . 21 (Β¬ (Β¬ (1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = βˆ…) β†’ (((1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = 1o) ↔ ((Β¬ (1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = βˆ…) ∨ ((1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = 1o))))
9088, 89ax-mp 5 . . . . . . . . . . . . . . . . . . . 20 (((1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = 1o) ↔ ((Β¬ (1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = βˆ…) ∨ ((1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = 1o)))
9187, 90bitr4i 187 . . . . . . . . . . . . . . . . . . 19 ((((1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = 1o) ∨ (Β¬ (1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = βˆ…)) ↔ ((1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = 1o))
9286, 91mpbiran2 941 . . . . . . . . . . . . . . . . . 18 ((((1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = 1o) ∨ (Β¬ (1st β€˜(π‘”β€˜π‘›)) = βˆ… ∧ 1o = βˆ…)) ↔ (1st β€˜(π‘”β€˜π‘›)) = βˆ…)
9385, 92bitrdi 196 . . . . . . . . . . . . . . . . 17 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) β†’ (1o = if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) ↔ (1st β€˜(π‘”β€˜π‘›)) = βˆ…))
9493adantr 276 . . . . . . . . . . . . . . . 16 ((((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) ∧ if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) = 1o) β†’ (1o = if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) ↔ (1st β€˜(π‘”β€˜π‘›)) = βˆ…))
9583, 94mpbid 147 . . . . . . . . . . . . . . 15 ((((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) ∧ if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) = 1o) β†’ (1st β€˜(π‘”β€˜π‘›)) = βˆ…)
96 eldju2ndl 7070 . . . . . . . . . . . . . . 15 (((π‘”β€˜π‘›) ∈ ({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o) ∧ (1st β€˜(π‘”β€˜π‘›)) = βˆ…) β†’ (2nd β€˜(π‘”β€˜π‘›)) ∈ {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}})
9781, 95, 96syl2anc 411 . . . . . . . . . . . . . 14 ((((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) ∧ if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) = 1o) β†’ (2nd β€˜(π‘”β€˜π‘›)) ∈ {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}})
98 biidd 172 . . . . . . . . . . . . . . 15 (𝑧 = (2nd β€˜(π‘”β€˜π‘›)) β†’ (𝑦 = {βˆ…} ↔ 𝑦 = {βˆ…}))
9998elrab 2893 . . . . . . . . . . . . . 14 ((2nd β€˜(π‘”β€˜π‘›)) ∈ {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} ↔ ((2nd β€˜(π‘”β€˜π‘›)) ∈ Ο‰ ∧ 𝑦 = {βˆ…}))
10097, 99sylib 122 . . . . . . . . . . . . 13 ((((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) ∧ if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) = 1o) β†’ ((2nd β€˜(π‘”β€˜π‘›)) ∈ Ο‰ ∧ 𝑦 = {βˆ…}))
101100simprd 114 . . . . . . . . . . . 12 ((((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) ∧ if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) = 1o) β†’ 𝑦 = {βˆ…})
102101ex 115 . . . . . . . . . . 11 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) β†’ (if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) = 1o β†’ 𝑦 = {βˆ…}))
10380, 102sylbid 150 . . . . . . . . . 10 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑛 ∈ Ο‰) β†’ (((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = 1o β†’ 𝑦 = {βˆ…}))
104103rexlimdva 2594 . . . . . . . . 9 ((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) β†’ (βˆƒπ‘› ∈ Ο‰ ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = 1o β†’ 𝑦 = {βˆ…}))
105 simplr 528 . . . . . . . . . . . 12 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑦 = {βˆ…}) β†’ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o))
106 biidd 172 . . . . . . . . . . . . . 14 (𝑧 = βˆ… β†’ (𝑦 = {βˆ…} ↔ 𝑦 = {βˆ…}))
107 peano1 4593 . . . . . . . . . . . . . . 15 βˆ… ∈ Ο‰
108107a1i 9 . . . . . . . . . . . . . 14 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑦 = {βˆ…}) β†’ βˆ… ∈ Ο‰)
109 simpr 110 . . . . . . . . . . . . . 14 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑦 = {βˆ…}) β†’ 𝑦 = {βˆ…})
110106, 108, 109elrabd 2895 . . . . . . . . . . . . 13 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑦 = {βˆ…}) β†’ βˆ… ∈ {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}})
111 djulcl 7049 . . . . . . . . . . . . 13 (βˆ… ∈ {𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} β†’ (inlβ€˜βˆ…) ∈ ({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o))
112110, 111syl 14 . . . . . . . . . . . 12 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑦 = {βˆ…}) β†’ (inlβ€˜βˆ…) ∈ ({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o))
113 foelrn 5753 . . . . . . . . . . . 12 ((𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o) ∧ (inlβ€˜βˆ…) ∈ ({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) β†’ βˆƒπ‘› ∈ Ο‰ (inlβ€˜βˆ…) = (π‘”β€˜π‘›))
114105, 112, 113syl2anc 411 . . . . . . . . . . 11 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑦 = {βˆ…}) β†’ βˆƒπ‘› ∈ Ο‰ (inlβ€˜βˆ…) = (π‘”β€˜π‘›))
11579adantlr 477 . . . . . . . . . . . . . 14 ((((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑦 = {βˆ…}) ∧ 𝑛 ∈ Ο‰) β†’ ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…))
116 fveq2 5515 . . . . . . . . . . . . . . . 16 ((inlβ€˜βˆ…) = (π‘”β€˜π‘›) β†’ (1st β€˜(inlβ€˜βˆ…)) = (1st β€˜(π‘”β€˜π‘›)))
117 1stinl 7072 . . . . . . . . . . . . . . . . 17 (βˆ… ∈ Ο‰ β†’ (1st β€˜(inlβ€˜βˆ…)) = βˆ…)
118107, 117ax-mp 5 . . . . . . . . . . . . . . . 16 (1st β€˜(inlβ€˜βˆ…)) = βˆ…
119116, 118eqtr3di 2225 . . . . . . . . . . . . . . 15 ((inlβ€˜βˆ…) = (π‘”β€˜π‘›) β†’ (1st β€˜(π‘”β€˜π‘›)) = βˆ…)
120119iftrued 3541 . . . . . . . . . . . . . 14 ((inlβ€˜βˆ…) = (π‘”β€˜π‘›) β†’ if((1st β€˜(π‘”β€˜π‘›)) = βˆ…, 1o, βˆ…) = 1o)
121115, 120sylan9eq 2230 . . . . . . . . . . . . 13 (((((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑦 = {βˆ…}) ∧ 𝑛 ∈ Ο‰) ∧ (inlβ€˜βˆ…) = (π‘”β€˜π‘›)) β†’ ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = 1o)
122121ex 115 . . . . . . . . . . . 12 ((((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑦 = {βˆ…}) ∧ 𝑛 ∈ Ο‰) β†’ ((inlβ€˜βˆ…) = (π‘”β€˜π‘›) β†’ ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = 1o))
123122reximdva 2579 . . . . . . . . . . 11 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑦 = {βˆ…}) β†’ (βˆƒπ‘› ∈ Ο‰ (inlβ€˜βˆ…) = (π‘”β€˜π‘›) β†’ βˆƒπ‘› ∈ Ο‰ ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = 1o))
124114, 123mpd 13 . . . . . . . . . 10 (((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) ∧ 𝑦 = {βˆ…}) β†’ βˆƒπ‘› ∈ Ο‰ ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = 1o)
125124ex 115 . . . . . . . . 9 ((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) β†’ (𝑦 = {βˆ…} β†’ βˆƒπ‘› ∈ Ο‰ ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = 1o))
126104, 125impbid 129 . . . . . . . 8 ((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) β†’ (βˆƒπ‘› ∈ Ο‰ ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = 1o ↔ 𝑦 = {βˆ…}))
127126notbid 667 . . . . . . 7 ((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) β†’ (Β¬ βˆƒπ‘› ∈ Ο‰ ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = 1o ↔ Β¬ 𝑦 = {βˆ…}))
128127notbid 667 . . . . . 6 ((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) β†’ (Β¬ Β¬ βˆƒπ‘› ∈ Ο‰ ((𝑀 ∈ Ο‰ ↦ if((1st β€˜(π‘”β€˜π‘€)) = βˆ…, 1o, βˆ…))β€˜π‘›) = 1o ↔ Β¬ Β¬ 𝑦 = {βˆ…}))
12977, 128, 1263imtr3d 202 . . . . 5 ((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) β†’ (Β¬ Β¬ 𝑦 = {βˆ…} β†’ 𝑦 = {βˆ…}))
130 df-stab 831 . . . . 5 (STAB 𝑦 = {βˆ…} ↔ (Β¬ Β¬ 𝑦 = {βˆ…} β†’ 𝑦 = {βˆ…}))
131129, 130sylibr 134 . . . 4 ((πœ‘ ∧ 𝑔:ω–ontoβ†’({𝑧 ∈ Ο‰ ∣ 𝑦 = {βˆ…}} βŠ” 1o)) β†’ STAB 𝑦 = {βˆ…})
13231, 131exlimddv 1898 . . 3 (πœ‘ β†’ STAB 𝑦 = {βˆ…})
133132adantr 276 . 2 ((πœ‘ ∧ 𝑦 βŠ† {βˆ…}) β†’ STAB 𝑦 = {βˆ…})
134133exmid1stab 4208 1 (πœ‘ β†’ EXMID)
Colors of variables: wff set class
Syntax hints:  Β¬ wn 3   β†’ wi 4   ∧ wa 104   ↔ wb 105   ∨ wo 708  STAB wstab 830  DECID wdc 834  βˆ€wal 1351   = wceq 1353  βˆƒwex 1492   ∈ wcel 2148  βˆ€wral 2455  βˆƒwrex 2456  {crab 2459  Vcvv 2737   βŠ† wss 3129  βˆ…c0 3422  ifcif 3534  {csn 3592   ↦ cmpt 4064  EXMIDwem 4194   I cid 4288  Ο‰com 4589   β†Ύ cres 4628  βŸΆwf 5212  β€“ontoβ†’wfo 5214  β€“1-1-ontoβ†’wf1o 5215  β€˜cfv 5216  (class class class)co 5874  1st c1st 6138  2nd c2nd 6139  1oc1o 6409  2oc2o 6410   β†‘π‘š cmap 6647   βŠ” cdju 7035  inlcinl 7043  Markovcmarkov 7148
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 614  ax-in2 615  ax-io 709  ax-5 1447  ax-7 1448  ax-gen 1449  ax-ie1 1493  ax-ie2 1494  ax-8 1504  ax-10 1505  ax-11 1506  ax-i12 1507  ax-bndl 1509  ax-4 1510  ax-17 1526  ax-i9 1530  ax-ial 1534  ax-i5r 1535  ax-13 2150  ax-14 2151  ax-ext 2159  ax-sep 4121  ax-nul 4129  ax-pow 4174  ax-pr 4209  ax-un 4433  ax-setind 4536  ax-iinf 4587
This theorem depends on definitions:  df-bi 117  df-stab 831  df-dc 835  df-3an 980  df-tru 1356  df-fal 1359  df-nf 1461  df-sb 1763  df-eu 2029  df-mo 2030  df-clab 2164  df-cleq 2170  df-clel 2173  df-nfc 2308  df-ne 2348  df-ral 2460  df-rex 2461  df-rab 2464  df-v 2739  df-sbc 2963  df-csb 3058  df-dif 3131  df-un 3133  df-in 3135  df-ss 3142  df-nul 3423  df-if 3535  df-pw 3577  df-sn 3598  df-pr 3599  df-op 3601  df-uni 3810  df-int 3845  df-br 4004  df-opab 4065  df-mpt 4066  df-tr 4102  df-exmid 4195  df-id 4293  df-iord 4366  df-on 4368  df-suc 4371  df-iom 4590  df-xp 4632  df-rel 4633  df-cnv 4634  df-co 4635  df-dm 4636  df-rn 4637  df-res 4638  df-ima 4639  df-iota 5178  df-fun 5218  df-fn 5219  df-f 5220  df-f1 5221  df-fo 5222  df-f1o 5223  df-fv 5224  df-ov 5877  df-oprab 5878  df-mpo 5879  df-1st 6140  df-2nd 6141  df-1o 6416  df-2o 6417  df-map 6649  df-dju 7036  df-inl 7045  df-inr 7046  df-markov 7149
This theorem is referenced by: (None)
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