Theorem disjpreima 33253

Description: A preimage of a disjoint set is disjoint. (Contributed by Thierry Arnoux, 7-Feb-2017.)

Assertion

Ref	Expression
disjpreima	⊢ ((Fun 𝐹 ∧ Disj 𝑥 ∈ 𝐴 𝐵) → Disj 𝑥 ∈ 𝐴 (◡𝐹 “ 𝐵))

Distinct variable groups:   𝑥,𝐴   𝑥,𝐹

Allowed substitution hint:   𝐵(𝑥)

Proof of Theorem disjpreima

Dummy variables 𝑦 𝑧 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		inpreima 7090	. . . . . . . . 9 ⊢ (Fun 𝐹 → (◡𝐹 “ (⦋𝑦 / 𝑥⦌𝐵 ∩ ⦋𝑧 / 𝑥⦌𝐵)) = ((◡𝐹 “ ⦋𝑦 / 𝑥⦌𝐵) ∩ (◡𝐹 “ ⦋𝑧 / 𝑥⦌𝐵)))
2		imaeq2 6061	. . . . . . . . . 10 ⊢ ((⦋𝑦 / 𝑥⦌𝐵 ∩ ⦋𝑧 / 𝑥⦌𝐵) = ∅ → (◡𝐹 “ (⦋𝑦 / 𝑥⦌𝐵 ∩ ⦋𝑧 / 𝑥⦌𝐵)) = (◡𝐹 “ ∅))
3		ima0 6088	. . . . . . . . . 10 ⊢ (◡𝐹 “ ∅) = ∅
4	2, 3	eqtrdi 2814	. . . . . . . . 9 ⊢ ((⦋𝑦 / 𝑥⦌𝐵 ∩ ⦋𝑧 / 𝑥⦌𝐵) = ∅ → (◡𝐹 “ (⦋𝑦 / 𝑥⦌𝐵 ∩ ⦋𝑧 / 𝑥⦌𝐵)) = ∅)
5	1, 4	sylan9req 2819	. . . . . . . 8 ⊢ ((Fun 𝐹 ∧ (⦋𝑦 / 𝑥⦌𝐵 ∩ ⦋𝑧 / 𝑥⦌𝐵) = ∅) → ((◡𝐹 “ ⦋𝑦 / 𝑥⦌𝐵) ∩ (◡𝐹 “ ⦋𝑧 / 𝑥⦌𝐵)) = ∅)
6	5	ex 418	. . . . . . 7 ⊢ (Fun 𝐹 → ((⦋𝑦 / 𝑥⦌𝐵 ∩ ⦋𝑧 / 𝑥⦌𝐵) = ∅ → ((◡𝐹 “ ⦋𝑦 / 𝑥⦌𝐵) ∩ (◡𝐹 “ ⦋𝑧 / 𝑥⦌𝐵)) = ∅))
7		csbima12 6089	. . . . . . . . . 10 ⊢ ⦋𝑦 / 𝑥⦌(◡𝐹 “ 𝐵) = (⦋𝑦 / 𝑥⦌◡𝐹 “ ⦋𝑦 / 𝑥⦌𝐵)
8		csbconstg 3870	. . . . . . . . . . . 12 ⊢ (𝑦 ∈ V → ⦋𝑦 / 𝑥⦌◡𝐹 = ◡𝐹)
9	8	elv 3459	. . . . . . . . . . 11 ⊢ ⦋𝑦 / 𝑥⦌◡𝐹 = ◡𝐹
10	9	imaeq1i 6062	. . . . . . . . . 10 ⊢ (⦋𝑦 / 𝑥⦌◡𝐹 “ ⦋𝑦 / 𝑥⦌𝐵) = (◡𝐹 “ ⦋𝑦 / 𝑥⦌𝐵)
11	7, 10	eqtri 2786	. . . . . . . . 9 ⊢ ⦋𝑦 / 𝑥⦌(◡𝐹 “ 𝐵) = (◡𝐹 “ ⦋𝑦 / 𝑥⦌𝐵)
12		csbima12 6089	. . . . . . . . . 10 ⊢ ⦋𝑧 / 𝑥⦌(◡𝐹 “ 𝐵) = (⦋𝑧 / 𝑥⦌◡𝐹 “ ⦋𝑧 / 𝑥⦌𝐵)
13		csbconstg 3870	. . . . . . . . . . . 12 ⊢ (𝑧 ∈ V → ⦋𝑧 / 𝑥⦌◡𝐹 = ◡𝐹)
14	13	elv 3459	. . . . . . . . . . 11 ⊢ ⦋𝑧 / 𝑥⦌◡𝐹 = ◡𝐹
15	14	imaeq1i 6062	. . . . . . . . . 10 ⊢ (⦋𝑧 / 𝑥⦌◡𝐹 “ ⦋𝑧 / 𝑥⦌𝐵) = (◡𝐹 “ ⦋𝑧 / 𝑥⦌𝐵)
16	12, 15	eqtri 2786	. . . . . . . . 9 ⊢ ⦋𝑧 / 𝑥⦌(◡𝐹 “ 𝐵) = (◡𝐹 “ ⦋𝑧 / 𝑥⦌𝐵)
17	11, 16	ineq12i 4118	. . . . . . . 8 ⊢ (⦋𝑦 / 𝑥⦌(◡𝐹 “ 𝐵) ∩ ⦋𝑧 / 𝑥⦌(◡𝐹 “ 𝐵)) = ((◡𝐹 “ ⦋𝑦 / 𝑥⦌𝐵) ∩ (◡𝐹 “ ⦋𝑧 / 𝑥⦌𝐵))
18	17	eqeq1i 2768	. . . . . . 7 ⊢ ((⦋𝑦 / 𝑥⦌(◡𝐹 “ 𝐵) ∩ ⦋𝑧 / 𝑥⦌(◡𝐹 “ 𝐵)) = ∅ ↔ ((◡𝐹 “ ⦋𝑦 / 𝑥⦌𝐵) ∩ (◡𝐹 “ ⦋𝑧 / 𝑥⦌𝐵)) = ∅)
19	6, 18	imbitrrdi 255	. . . . . 6 ⊢ (Fun 𝐹 → ((⦋𝑦 / 𝑥⦌𝐵 ∩ ⦋𝑧 / 𝑥⦌𝐵) = ∅ → (⦋𝑦 / 𝑥⦌(◡𝐹 “ 𝐵) ∩ ⦋𝑧 / 𝑥⦌(◡𝐹 “ 𝐵)) = ∅))
20	19	orim2d 982	. . . . 5 ⊢ (Fun 𝐹 → ((𝑦 = 𝑧 ∨ (⦋𝑦 / 𝑥⦌𝐵 ∩ ⦋𝑧 / 𝑥⦌𝐵) = ∅) → (𝑦 = 𝑧 ∨ (⦋𝑦 / 𝑥⦌(◡𝐹 “ 𝐵) ∩ ⦋𝑧 / 𝑥⦌(◡𝐹 “ 𝐵)) = ∅)))
21	20	ralimdv 3180	. . . 4 ⊢ (Fun 𝐹 → (∀𝑧 ∈ 𝐴 (𝑦 = 𝑧 ∨ (⦋𝑦 / 𝑥⦌𝐵 ∩ ⦋𝑧 / 𝑥⦌𝐵) = ∅) → ∀𝑧 ∈ 𝐴 (𝑦 = 𝑧 ∨ (⦋𝑦 / 𝑥⦌(◡𝐹 “ 𝐵) ∩ ⦋𝑧 / 𝑥⦌(◡𝐹 “ 𝐵)) = ∅)))
22	21	ralimdv 3180	. . 3 ⊢ (Fun 𝐹 → (∀𝑦 ∈ 𝐴 ∀𝑧 ∈ 𝐴 (𝑦 = 𝑧 ∨ (⦋𝑦 / 𝑥⦌𝐵 ∩ ⦋𝑧 / 𝑥⦌𝐵) = ∅) → ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ 𝐴 (𝑦 = 𝑧 ∨ (⦋𝑦 / 𝑥⦌(◡𝐹 “ 𝐵) ∩ ⦋𝑧 / 𝑥⦌(◡𝐹 “ 𝐵)) = ∅)))
23		disjors 5089	. . 3 ⊢ (Disj 𝑥 ∈ 𝐴 𝐵 ↔ ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ 𝐴 (𝑦 = 𝑧 ∨ (⦋𝑦 / 𝑥⦌𝐵 ∩ ⦋𝑧 / 𝑥⦌𝐵) = ∅))
24		disjors 5089	. . 3 ⊢ (Disj 𝑥 ∈ 𝐴 (◡𝐹 “ 𝐵) ↔ ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ 𝐴 (𝑦 = 𝑧 ∨ (⦋𝑦 / 𝑥⦌(◡𝐹 “ 𝐵) ∩ ⦋𝑧 / 𝑥⦌(◡𝐹 “ 𝐵)) = ∅))
25	22, 23, 24	3imtr4g 299	. 2 ⊢ (Fun 𝐹 → (Disj 𝑥 ∈ 𝐴 𝐵 → Disj 𝑥 ∈ 𝐴 (◡𝐹 “ 𝐵)))
26	25	imp 412	1 ⊢ ((Fun 𝐹 ∧ Disj 𝑥 ∈ 𝐴 𝐵) → Disj 𝑥 ∈ 𝐴 (◡𝐹 “ 𝐵))

This proof depends on syntax axioms:   → wi 4   ∧ wa 401   ∨ wo 861   = wceq 1570  ∀wral 3080  Vcvv 3454  ⦋csb 3851   ∩ cin 4092  ∅c0 4281  Disj wdisj 5073  ^◡ccnv 5655   “ cima 5659  Fun wfun 6555

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1945  ax-6 2002  ax-7 2043  ax-8 2149  ax-9 2157  ax-10 2180  ax-11 2197  ax-12 2216  ax-ext 2735  ax-sep 5253  ax-pr 5396

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1813  df-nf 1817  df-sb 2102  df-mo 2567  df-clab 2742  df-cleq 2755  df-clel 2839  df-nfc 2913  df-ral 3081  df-rex 3091  df-rmo 3369  df-rab 3417  df-v 3456  df-sbc 3743  df-csb 3852  df-ss 3901  df-dif 4050  df-in 4094  df-un 4154  df-nul 4282  df-if 4486  df-sn 4589  df-pr 4591  df-op 4839  df-disj 5074  df-br 5107  df-opab 5172  df-id 5551  df-xp 5662  df-rel 5663  df-cnv 5664  df-co 5665  df-dm 5666  df-rn 5667  df-res 5668  df-ima 5669  df-fun 6563

This theorem is used by:  fnpreimac  33339  elrspunidl  34062  sibfof  35055  dstrvprob  35187