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Mirrors > Home > ILE Home > Th. List > fvimacnv | GIF version |
Description: The argument of a function value belongs to the preimage of any class containing the function value. Raph Levien remarks: "This proof is unsatisfying, because it seems to me that funimass2 5092 could probably be strengthened to a biconditional." (Contributed by Raph Levien, 20-Nov-2006.) |
Ref | Expression |
---|---|
fvimacnv | ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → ((𝐹‘𝐴) ∈ 𝐵 ↔ 𝐴 ∈ (◡𝐹 “ 𝐵))) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | funfvop 5411 | . . . . 5 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → 〈𝐴, (𝐹‘𝐴)〉 ∈ 𝐹) | |
2 | funfvex 5322 | . . . . . 6 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → (𝐹‘𝐴) ∈ V) | |
3 | opelcnvg 4616 | . . . . . 6 ⊢ (((𝐹‘𝐴) ∈ V ∧ 𝐴 ∈ dom 𝐹) → (〈(𝐹‘𝐴), 𝐴〉 ∈ ◡𝐹 ↔ 〈𝐴, (𝐹‘𝐴)〉 ∈ 𝐹)) | |
4 | 2, 3 | sylancom 411 | . . . . 5 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → (〈(𝐹‘𝐴), 𝐴〉 ∈ ◡𝐹 ↔ 〈𝐴, (𝐹‘𝐴)〉 ∈ 𝐹)) |
5 | 1, 4 | mpbird 165 | . . . 4 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → 〈(𝐹‘𝐴), 𝐴〉 ∈ ◡𝐹) |
6 | elimasng 4800 | . . . . 5 ⊢ (((𝐹‘𝐴) ∈ V ∧ 𝐴 ∈ dom 𝐹) → (𝐴 ∈ (◡𝐹 “ {(𝐹‘𝐴)}) ↔ 〈(𝐹‘𝐴), 𝐴〉 ∈ ◡𝐹)) | |
7 | 2, 6 | sylancom 411 | . . . 4 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → (𝐴 ∈ (◡𝐹 “ {(𝐹‘𝐴)}) ↔ 〈(𝐹‘𝐴), 𝐴〉 ∈ ◡𝐹)) |
8 | 5, 7 | mpbird 165 | . . 3 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → 𝐴 ∈ (◡𝐹 “ {(𝐹‘𝐴)})) |
9 | snssg 3573 | . . . . . . . 8 ⊢ ((𝐹‘𝐴) ∈ V → ((𝐹‘𝐴) ∈ 𝐵 ↔ {(𝐹‘𝐴)} ⊆ 𝐵)) | |
10 | 2, 9 | syl 14 | . . . . . . 7 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → ((𝐹‘𝐴) ∈ 𝐵 ↔ {(𝐹‘𝐴)} ⊆ 𝐵)) |
11 | imass2 4808 | . . . . . . 7 ⊢ ({(𝐹‘𝐴)} ⊆ 𝐵 → (◡𝐹 “ {(𝐹‘𝐴)}) ⊆ (◡𝐹 “ 𝐵)) | |
12 | 10, 11 | syl6bi 161 | . . . . . 6 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → ((𝐹‘𝐴) ∈ 𝐵 → (◡𝐹 “ {(𝐹‘𝐴)}) ⊆ (◡𝐹 “ 𝐵))) |
13 | 12 | imp 122 | . . . . 5 ⊢ (((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) ∧ (𝐹‘𝐴) ∈ 𝐵) → (◡𝐹 “ {(𝐹‘𝐴)}) ⊆ (◡𝐹 “ 𝐵)) |
14 | 13 | sseld 3024 | . . . 4 ⊢ (((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) ∧ (𝐹‘𝐴) ∈ 𝐵) → (𝐴 ∈ (◡𝐹 “ {(𝐹‘𝐴)}) → 𝐴 ∈ (◡𝐹 “ 𝐵))) |
15 | 14 | ex 113 | . . 3 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → ((𝐹‘𝐴) ∈ 𝐵 → (𝐴 ∈ (◡𝐹 “ {(𝐹‘𝐴)}) → 𝐴 ∈ (◡𝐹 “ 𝐵)))) |
16 | 8, 15 | mpid 41 | . 2 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → ((𝐹‘𝐴) ∈ 𝐵 → 𝐴 ∈ (◡𝐹 “ 𝐵))) |
17 | fvimacnvi 5413 | . . . 4 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ (◡𝐹 “ 𝐵)) → (𝐹‘𝐴) ∈ 𝐵) | |
18 | 17 | ex 113 | . . 3 ⊢ (Fun 𝐹 → (𝐴 ∈ (◡𝐹 “ 𝐵) → (𝐹‘𝐴) ∈ 𝐵)) |
19 | 18 | adantr 270 | . 2 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → (𝐴 ∈ (◡𝐹 “ 𝐵) → (𝐹‘𝐴) ∈ 𝐵)) |
20 | 16, 19 | impbid 127 | 1 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → ((𝐹‘𝐴) ∈ 𝐵 ↔ 𝐴 ∈ (◡𝐹 “ 𝐵))) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 102 ↔ wb 103 ∈ wcel 1438 Vcvv 2619 ⊆ wss 2999 {csn 3446 〈cop 3449 ◡ccnv 4437 dom cdm 4438 “ cima 4441 Fun wfun 5009 ‘cfv 5015 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 104 ax-ia2 105 ax-ia3 106 ax-io 665 ax-5 1381 ax-7 1382 ax-gen 1383 ax-ie1 1427 ax-ie2 1428 ax-8 1440 ax-10 1441 ax-11 1442 ax-i12 1443 ax-bndl 1444 ax-4 1445 ax-14 1450 ax-17 1464 ax-i9 1468 ax-ial 1472 ax-i5r 1473 ax-ext 2070 ax-sep 3957 ax-pow 4009 ax-pr 4036 |
This theorem depends on definitions: df-bi 115 df-3an 926 df-tru 1292 df-nf 1395 df-sb 1693 df-eu 1951 df-mo 1952 df-clab 2075 df-cleq 2081 df-clel 2084 df-nfc 2217 df-ral 2364 df-rex 2365 df-v 2621 df-sbc 2841 df-un 3003 df-in 3005 df-ss 3012 df-pw 3431 df-sn 3452 df-pr 3453 df-op 3455 df-uni 3654 df-br 3846 df-opab 3900 df-id 4120 df-xp 4444 df-rel 4445 df-cnv 4446 df-co 4447 df-dm 4448 df-rn 4449 df-res 4450 df-ima 4451 df-iota 4980 df-fun 5017 df-fn 5018 df-fv 5023 |
This theorem is referenced by: funimass3 5415 elpreima 5418 fisumss 10784 |
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