Theorem riinerm 6755

Description: The relative intersection of a family of equivalence relations is an equivalence relation. (Contributed by Mario Carneiro, 27-Sep-2015.)

Assertion

Ref	Expression
riinerm	⊢ ((∃𝑦 𝑦 ∈ 𝐴 ∧ ∀𝑥 ∈ 𝐴 𝑅 Er 𝐵) → ((𝐵 × 𝐵) ∩ ∩ 𝑥 ∈ 𝐴 𝑅) Er 𝐵)

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

Allowed substitution hints:   𝐵(𝑦)   𝑅(𝑥,𝑦)

Proof of Theorem riinerm

Dummy variable 𝑎 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		iinerm 6754	. 2 ⊢ ((∃𝑦 𝑦 ∈ 𝐴 ∧ ∀𝑥 ∈ 𝐴 𝑅 Er 𝐵) → ∩ 𝑥 ∈ 𝐴 𝑅 Er 𝐵)
2		eleq1 2292	. . . . . 6 ⊢ (𝑥 = 𝑎 → (𝑥 ∈ 𝐴 ↔ 𝑎 ∈ 𝐴))
3	2	cbvexv 1965	. . . . 5 ⊢ (∃𝑥 𝑥 ∈ 𝐴 ↔ ∃𝑎 𝑎 ∈ 𝐴)
4		eleq1 2292	. . . . . 6 ⊢ (𝑎 = 𝑦 → (𝑎 ∈ 𝐴 ↔ 𝑦 ∈ 𝐴))
5	4	cbvexv 1965	. . . . 5 ⊢ (∃𝑎 𝑎 ∈ 𝐴 ↔ ∃𝑦 𝑦 ∈ 𝐴)
6	3, 5	bitri 184	. . . 4 ⊢ (∃𝑥 𝑥 ∈ 𝐴 ↔ ∃𝑦 𝑦 ∈ 𝐴)
7		erssxp 6703	. . . . . . 7 ⊢ (𝑅 Er 𝐵 → 𝑅 ⊆ (𝐵 × 𝐵))
8	7	ralimi 2593	. . . . . 6 ⊢ (∀𝑥 ∈ 𝐴 𝑅 Er 𝐵 → ∀𝑥 ∈ 𝐴 𝑅 ⊆ (𝐵 × 𝐵))
9		riinm 4038	. . . . . 6 ⊢ ((∀𝑥 ∈ 𝐴 𝑅 ⊆ (𝐵 × 𝐵) ∧ ∃𝑥 𝑥 ∈ 𝐴) → ((𝐵 × 𝐵) ∩ ∩ 𝑥 ∈ 𝐴 𝑅) = ∩ 𝑥 ∈ 𝐴 𝑅)
10	8, 9	sylan 283	. . . . 5 ⊢ ((∀𝑥 ∈ 𝐴 𝑅 Er 𝐵 ∧ ∃𝑥 𝑥 ∈ 𝐴) → ((𝐵 × 𝐵) ∩ ∩ 𝑥 ∈ 𝐴 𝑅) = ∩ 𝑥 ∈ 𝐴 𝑅)
11		ereq1 6687	. . . . 5 ⊢ (((𝐵 × 𝐵) ∩ ∩ 𝑥 ∈ 𝐴 𝑅) = ∩ 𝑥 ∈ 𝐴 𝑅 → (((𝐵 × 𝐵) ∩ ∩ 𝑥 ∈ 𝐴 𝑅) Er 𝐵 ↔ ∩ 𝑥 ∈ 𝐴 𝑅 Er 𝐵))
12	10, 11	syl 14	. . . 4 ⊢ ((∀𝑥 ∈ 𝐴 𝑅 Er 𝐵 ∧ ∃𝑥 𝑥 ∈ 𝐴) → (((𝐵 × 𝐵) ∩ ∩ 𝑥 ∈ 𝐴 𝑅) Er 𝐵 ↔ ∩ 𝑥 ∈ 𝐴 𝑅 Er 𝐵))
13	6, 12	sylan2br 288	. . 3 ⊢ ((∀𝑥 ∈ 𝐴 𝑅 Er 𝐵 ∧ ∃𝑦 𝑦 ∈ 𝐴) → (((𝐵 × 𝐵) ∩ ∩ 𝑥 ∈ 𝐴 𝑅) Er 𝐵 ↔ ∩ 𝑥 ∈ 𝐴 𝑅 Er 𝐵))
14	13	ancoms 268	. 2 ⊢ ((∃𝑦 𝑦 ∈ 𝐴 ∧ ∀𝑥 ∈ 𝐴 𝑅 Er 𝐵) → (((𝐵 × 𝐵) ∩ ∩ 𝑥 ∈ 𝐴 𝑅) Er 𝐵 ↔ ∩ 𝑥 ∈ 𝐴 𝑅 Er 𝐵))
15	1, 14	mpbird 167	1 ⊢ ((∃𝑦 𝑦 ∈ 𝐴 ∧ ∀𝑥 ∈ 𝐴 𝑅 Er 𝐵) → ((𝐵 × 𝐵) ∩ ∩ 𝑥 ∈ 𝐴 𝑅) Er 𝐵)

Syntax hints:   → wi 4   ∧ wa 104   ↔ wb 105   = wceq 1395  ∃wex 1538   ∈ wcel 2200  ∀wral 2508   ∩ cin 3196   ⊆ wss 3197  ∩ ciin 3966   × cxp 4717   Er wer 6677

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-io 714  ax-5 1493  ax-7 1494  ax-gen 1495  ax-ie1 1539  ax-ie2 1540  ax-8 1550  ax-10 1551  ax-11 1552  ax-i12 1553  ax-bndl 1555  ax-4 1556  ax-17 1572  ax-i9 1576  ax-ial 1580  ax-i5r 1581  ax-14 2203  ax-ext 2211  ax-sep 4202  ax-pow 4258  ax-pr 4293

This theorem depends on definitions:  df-bi 117  df-3an 1004  df-tru 1398  df-nf 1507  df-sb 1809  df-eu 2080  df-mo 2081  df-clab 2216  df-cleq 2222  df-clel 2225  df-nfc 2361  df-ral 2513  df-rex 2514  df-v 2801  df-un 3201  df-in 3203  df-ss 3210  df-pw 3651  df-sn 3672  df-pr 3673  df-op 3675  df-iin 3968  df-br 4084  df-opab 4146  df-xp 4725  df-rel 4726  df-cnv 4727  df-co 4728  df-dm 4729  df-rn 4730  df-er 6680

This theorem is referenced by: (None)