Theorem oadif1 42800

Description: Express the set difference of an ordinal sum and its left addend as a class of sums. (Contributed by RP, 13-Feb-2025.)

Assertion

Ref	Expression
oadif1	⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → ((𝐴 +o 𝐵) ∖ 𝐴) = {𝑥 ∣ ∃𝑏 ∈ 𝐵 𝑥 = (𝐴 +o 𝑏)})

Distinct variable groups:   𝐴,𝑏,𝑥   𝐵,𝑏,𝑥

Proof of Theorem oadif1

Dummy variable 𝑦 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		simpl 482	. . . . . . . . . 10 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → 𝐴 ∈ On)
2		oacl 8550	. . . . . . . . . . 11 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 +o 𝐵) ∈ On)
3		onelon 6389	. . . . . . . . . . 11 ⊢ (((𝐴 +o 𝐵) ∈ On ∧ 𝑦 ∈ (𝐴 +o 𝐵)) → 𝑦 ∈ On)
4	2, 3	sylan 579	. . . . . . . . . 10 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ 𝑦 ∈ (𝐴 +o 𝐵)) → 𝑦 ∈ On)
5		ontri1 6398	. . . . . . . . . 10 ⊢ ((𝐴 ∈ On ∧ 𝑦 ∈ On) → (𝐴 ⊆ 𝑦 ↔ ¬ 𝑦 ∈ 𝐴))
6	1, 4, 5	syl2an2r 684	. . . . . . . . 9 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ 𝑦 ∈ (𝐴 +o 𝐵)) → (𝐴 ⊆ 𝑦 ↔ ¬ 𝑦 ∈ 𝐴))
7	6	pm5.32da 578	. . . . . . . 8 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → ((𝑦 ∈ (𝐴 +o 𝐵) ∧ 𝐴 ⊆ 𝑦) ↔ (𝑦 ∈ (𝐴 +o 𝐵) ∧ ¬ 𝑦 ∈ 𝐴)))
8		ancom 460	. . . . . . . 8 ⊢ ((𝑦 ∈ (𝐴 +o 𝐵) ∧ 𝐴 ⊆ 𝑦) ↔ (𝐴 ⊆ 𝑦 ∧ 𝑦 ∈ (𝐴 +o 𝐵)))
9	7, 8	bitr3di 286	. . . . . . 7 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → ((𝑦 ∈ (𝐴 +o 𝐵) ∧ ¬ 𝑦 ∈ 𝐴) ↔ (𝐴 ⊆ 𝑦 ∧ 𝑦 ∈ (𝐴 +o 𝐵))))
10		oawordex2 42746	. . . . . . 7 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ (𝐴 ⊆ 𝑦 ∧ 𝑦 ∈ (𝐴 +o 𝐵))) → ∃𝑏 ∈ 𝐵 (𝐴 +o 𝑏) = 𝑦)
11	9, 10	sylbida 591	. . . . . 6 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ (𝑦 ∈ (𝐴 +o 𝐵) ∧ ¬ 𝑦 ∈ 𝐴)) → ∃𝑏 ∈ 𝐵 (𝐴 +o 𝑏) = 𝑦)
12		eqcom 2735	. . . . . . 7 ⊢ ((𝐴 +o 𝑏) = 𝑦 ↔ 𝑦 = (𝐴 +o 𝑏))
13	12	rexbii 3090	. . . . . 6 ⊢ (∃𝑏 ∈ 𝐵 (𝐴 +o 𝑏) = 𝑦 ↔ ∃𝑏 ∈ 𝐵 𝑦 = (𝐴 +o 𝑏))
14	11, 13	sylib 217	. . . . 5 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ (𝑦 ∈ (𝐴 +o 𝐵) ∧ ¬ 𝑦 ∈ 𝐴)) → ∃𝑏 ∈ 𝐵 𝑦 = (𝐴 +o 𝑏))
15	14	ex 412	. . . 4 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → ((𝑦 ∈ (𝐴 +o 𝐵) ∧ ¬ 𝑦 ∈ 𝐴) → ∃𝑏 ∈ 𝐵 𝑦 = (𝐴 +o 𝑏)))
16		simpr 484	. . . . . . 7 ⊢ ((((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ 𝑏 ∈ 𝐵) ∧ 𝑦 = (𝐴 +o 𝑏)) → 𝑦 = (𝐴 +o 𝑏))
17		oaordi 8561	. . . . . . . . . 10 ⊢ ((𝐵 ∈ On ∧ 𝐴 ∈ On) → (𝑏 ∈ 𝐵 → (𝐴 +o 𝑏) ∈ (𝐴 +o 𝐵)))
18	17	ancoms 458	. . . . . . . . 9 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝑏 ∈ 𝐵 → (𝐴 +o 𝑏) ∈ (𝐴 +o 𝐵)))
19	18	imp 406	. . . . . . . 8 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ 𝑏 ∈ 𝐵) → (𝐴 +o 𝑏) ∈ (𝐴 +o 𝐵))
20	19	adantr 480	. . . . . . 7 ⊢ ((((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ 𝑏 ∈ 𝐵) ∧ 𝑦 = (𝐴 +o 𝑏)) → (𝐴 +o 𝑏) ∈ (𝐴 +o 𝐵))
21	16, 20	eqeltrd 2829	. . . . . 6 ⊢ ((((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ 𝑏 ∈ 𝐵) ∧ 𝑦 = (𝐴 +o 𝑏)) → 𝑦 ∈ (𝐴 +o 𝐵))
22		simpr 484	. . . . . . . . . . 11 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → 𝐵 ∈ On)
23		onelon 6389	. . . . . . . . . . 11 ⊢ ((𝐵 ∈ On ∧ 𝑏 ∈ 𝐵) → 𝑏 ∈ On)
24	22, 23	sylan 579	. . . . . . . . . 10 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ 𝑏 ∈ 𝐵) → 𝑏 ∈ On)
25		oaword1 8567	. . . . . . . . . 10 ⊢ ((𝐴 ∈ On ∧ 𝑏 ∈ On) → 𝐴 ⊆ (𝐴 +o 𝑏))
26	1, 24, 25	syl2an2r 684	. . . . . . . . 9 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ 𝑏 ∈ 𝐵) → 𝐴 ⊆ (𝐴 +o 𝑏))
27		oacl 8550	. . . . . . . . . . 11 ⊢ ((𝐴 ∈ On ∧ 𝑏 ∈ On) → (𝐴 +o 𝑏) ∈ On)
28	1, 24, 27	syl2an2r 684	. . . . . . . . . 10 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ 𝑏 ∈ 𝐵) → (𝐴 +o 𝑏) ∈ On)
29		ontri1 6398	. . . . . . . . . 10 ⊢ ((𝐴 ∈ On ∧ (𝐴 +o 𝑏) ∈ On) → (𝐴 ⊆ (𝐴 +o 𝑏) ↔ ¬ (𝐴 +o 𝑏) ∈ 𝐴))
30	1, 28, 29	syl2an2r 684	. . . . . . . . 9 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ 𝑏 ∈ 𝐵) → (𝐴 ⊆ (𝐴 +o 𝑏) ↔ ¬ (𝐴 +o 𝑏) ∈ 𝐴))
31	26, 30	mpbid 231	. . . . . . . 8 ⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ 𝑏 ∈ 𝐵) → ¬ (𝐴 +o 𝑏) ∈ 𝐴)
32	31	adantr 480	. . . . . . 7 ⊢ ((((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ 𝑏 ∈ 𝐵) ∧ 𝑦 = (𝐴 +o 𝑏)) → ¬ (𝐴 +o 𝑏) ∈ 𝐴)
33	16, 32	eqneltrd 2849	. . . . . 6 ⊢ ((((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ 𝑏 ∈ 𝐵) ∧ 𝑦 = (𝐴 +o 𝑏)) → ¬ 𝑦 ∈ 𝐴)
34	21, 33	jca 511	. . . . 5 ⊢ ((((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ 𝑏 ∈ 𝐵) ∧ 𝑦 = (𝐴 +o 𝑏)) → (𝑦 ∈ (𝐴 +o 𝐵) ∧ ¬ 𝑦 ∈ 𝐴))
35	34	rexlimdva2 3153	. . . 4 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (∃𝑏 ∈ 𝐵 𝑦 = (𝐴 +o 𝑏) → (𝑦 ∈ (𝐴 +o 𝐵) ∧ ¬ 𝑦 ∈ 𝐴)))
36	15, 35	impbid 211	. . 3 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → ((𝑦 ∈ (𝐴 +o 𝐵) ∧ ¬ 𝑦 ∈ 𝐴) ↔ ∃𝑏 ∈ 𝐵 𝑦 = (𝐴 +o 𝑏)))
37		eldif 3955	. . 3 ⊢ (𝑦 ∈ ((𝐴 +o 𝐵) ∖ 𝐴) ↔ (𝑦 ∈ (𝐴 +o 𝐵) ∧ ¬ 𝑦 ∈ 𝐴))
38		vex 3474	. . . 4 ⊢ 𝑦 ∈ V
39		eqeq1 2732	. . . . 5 ⊢ (𝑥 = 𝑦 → (𝑥 = (𝐴 +o 𝑏) ↔ 𝑦 = (𝐴 +o 𝑏)))
40	39	rexbidv 3174	. . . 4 ⊢ (𝑥 = 𝑦 → (∃𝑏 ∈ 𝐵 𝑥 = (𝐴 +o 𝑏) ↔ ∃𝑏 ∈ 𝐵 𝑦 = (𝐴 +o 𝑏)))
41	38, 40	elab 3666	. . 3 ⊢ (𝑦 ∈ {𝑥 ∣ ∃𝑏 ∈ 𝐵 𝑥 = (𝐴 +o 𝑏)} ↔ ∃𝑏 ∈ 𝐵 𝑦 = (𝐴 +o 𝑏))
42	36, 37, 41	3bitr4g 314	. 2 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝑦 ∈ ((𝐴 +o 𝐵) ∖ 𝐴) ↔ 𝑦 ∈ {𝑥 ∣ ∃𝑏 ∈ 𝐵 𝑥 = (𝐴 +o 𝑏)}))
43	42	eqrdv 2726	1 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → ((𝐴 +o 𝐵) ∖ 𝐴) = {𝑥 ∣ ∃𝑏 ∈ 𝐵 𝑥 = (𝐴 +o 𝑏)})

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 205   ∧ wa 395   = wceq 1534   ∈ wcel 2099  {cab 2705  ∃wrex 3066   ∖ cdif 3942   ⊆ wss 3945  Oncon0 6364  (class class class)co 7415   +_o coa 8478

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1790  ax-4 1804  ax-5 1906  ax-6 1964  ax-7 2004  ax-8 2101  ax-9 2109  ax-10 2130  ax-11 2147  ax-12 2167  ax-ext 2699  ax-rep 5280  ax-sep 5294  ax-nul 5301  ax-pr 5424  ax-un 7735

This theorem depends on definitions:  df-bi 206  df-an 396  df-or 847  df-3or 1086  df-3an 1087  df-tru 1537  df-fal 1547  df-ex 1775  df-nf 1779  df-sb 2061  df-mo 2530  df-eu 2559  df-clab 2706  df-cleq 2720  df-clel 2806  df-nfc 2881  df-ne 2937  df-ral 3058  df-rex 3067  df-rmo 3372  df-reu 3373  df-rab 3429  df-v 3472  df-sbc 3776  df-csb 3891  df-dif 3948  df-un 3950  df-in 3952  df-ss 3962  df-pss 3964  df-nul 4320  df-if 4526  df-pw 4601  df-sn 4626  df-pr 4628  df-op 4632  df-uni 4905  df-int 4946  df-iun 4994  df-br 5144  df-opab 5206  df-mpt 5227  df-tr 5261  df-id 5571  df-eprel 5577  df-po 5585  df-so 5586  df-fr 5628  df-we 5630  df-xp 5679  df-rel 5680  df-cnv 5681  df-co 5682  df-dm 5683  df-rn 5684  df-res 5685  df-ima 5686  df-pred 6300  df-ord 6367  df-on 6368  df-lim 6369  df-suc 6370  df-iota 6495  df-fun 6545  df-fn 6546  df-f 6547  df-f1 6548  df-fo 6549  df-f1o 6550  df-fv 6551  df-ov 7418  df-oprab 7419  df-mpo 7420  df-om 7866  df-2nd 7989  df-frecs 8281  df-wrecs 8312  df-recs 8386  df-rdg 8425  df-oadd 8485

This theorem is referenced by:  oaun2  42801  oaun3  42802