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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 5196 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 5525 | . . . . 5 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → 〈𝐴, (𝐹‘𝐴)〉 ∈ 𝐹) | |
2 | funfvex 5431 | . . . . . 6 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → (𝐹‘𝐴) ∈ V) | |
3 | opelcnvg 4714 | . . . . . 6 ⊢ (((𝐹‘𝐴) ∈ V ∧ 𝐴 ∈ dom 𝐹) → (〈(𝐹‘𝐴), 𝐴〉 ∈ ◡𝐹 ↔ 〈𝐴, (𝐹‘𝐴)〉 ∈ 𝐹)) | |
4 | 2, 3 | sylancom 416 | . . . . 5 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → (〈(𝐹‘𝐴), 𝐴〉 ∈ ◡𝐹 ↔ 〈𝐴, (𝐹‘𝐴)〉 ∈ 𝐹)) |
5 | 1, 4 | mpbird 166 | . . . 4 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → 〈(𝐹‘𝐴), 𝐴〉 ∈ ◡𝐹) |
6 | elimasng 4902 | . . . . 5 ⊢ (((𝐹‘𝐴) ∈ V ∧ 𝐴 ∈ dom 𝐹) → (𝐴 ∈ (◡𝐹 “ {(𝐹‘𝐴)}) ↔ 〈(𝐹‘𝐴), 𝐴〉 ∈ ◡𝐹)) | |
7 | 2, 6 | sylancom 416 | . . . 4 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → (𝐴 ∈ (◡𝐹 “ {(𝐹‘𝐴)}) ↔ 〈(𝐹‘𝐴), 𝐴〉 ∈ ◡𝐹)) |
8 | 5, 7 | mpbird 166 | . . 3 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → 𝐴 ∈ (◡𝐹 “ {(𝐹‘𝐴)})) |
9 | snssg 3651 | . . . . . . . 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 4910 | . . . . . . 7 ⊢ ({(𝐹‘𝐴)} ⊆ 𝐵 → (◡𝐹 “ {(𝐹‘𝐴)}) ⊆ (◡𝐹 “ 𝐵)) | |
12 | 10, 11 | syl6bi 162 | . . . . . 6 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → ((𝐹‘𝐴) ∈ 𝐵 → (◡𝐹 “ {(𝐹‘𝐴)}) ⊆ (◡𝐹 “ 𝐵))) |
13 | 12 | imp 123 | . . . . 5 ⊢ (((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) ∧ (𝐹‘𝐴) ∈ 𝐵) → (◡𝐹 “ {(𝐹‘𝐴)}) ⊆ (◡𝐹 “ 𝐵)) |
14 | 13 | sseld 3091 | . . . 4 ⊢ (((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) ∧ (𝐹‘𝐴) ∈ 𝐵) → (𝐴 ∈ (◡𝐹 “ {(𝐹‘𝐴)}) → 𝐴 ∈ (◡𝐹 “ 𝐵))) |
15 | 14 | ex 114 | . . 3 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → ((𝐹‘𝐴) ∈ 𝐵 → (𝐴 ∈ (◡𝐹 “ {(𝐹‘𝐴)}) → 𝐴 ∈ (◡𝐹 “ 𝐵)))) |
16 | 8, 15 | mpid 42 | . 2 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → ((𝐹‘𝐴) ∈ 𝐵 → 𝐴 ∈ (◡𝐹 “ 𝐵))) |
17 | fvimacnvi 5527 | . . . 4 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ (◡𝐹 “ 𝐵)) → (𝐹‘𝐴) ∈ 𝐵) | |
18 | 17 | ex 114 | . . 3 ⊢ (Fun 𝐹 → (𝐴 ∈ (◡𝐹 “ 𝐵) → (𝐹‘𝐴) ∈ 𝐵)) |
19 | 18 | adantr 274 | . 2 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → (𝐴 ∈ (◡𝐹 “ 𝐵) → (𝐹‘𝐴) ∈ 𝐵)) |
20 | 16, 19 | impbid 128 | 1 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → ((𝐹‘𝐴) ∈ 𝐵 ↔ 𝐴 ∈ (◡𝐹 “ 𝐵))) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 103 ↔ wb 104 ∈ wcel 1480 Vcvv 2681 ⊆ wss 3066 {csn 3522 〈cop 3525 ◡ccnv 4533 dom cdm 4534 “ cima 4537 Fun wfun 5112 ‘cfv 5118 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 105 ax-ia2 106 ax-ia3 107 ax-io 698 ax-5 1423 ax-7 1424 ax-gen 1425 ax-ie1 1469 ax-ie2 1470 ax-8 1482 ax-10 1483 ax-11 1484 ax-i12 1485 ax-bndl 1486 ax-4 1487 ax-14 1492 ax-17 1506 ax-i9 1510 ax-ial 1514 ax-i5r 1515 ax-ext 2119 ax-sep 4041 ax-pow 4093 ax-pr 4126 |
This theorem depends on definitions: df-bi 116 df-3an 964 df-tru 1334 df-nf 1437 df-sb 1736 df-eu 2000 df-mo 2001 df-clab 2124 df-cleq 2130 df-clel 2133 df-nfc 2268 df-ral 2419 df-rex 2420 df-v 2683 df-sbc 2905 df-un 3070 df-in 3072 df-ss 3079 df-pw 3507 df-sn 3528 df-pr 3529 df-op 3531 df-uni 3732 df-br 3925 df-opab 3985 df-id 4210 df-xp 4540 df-rel 4541 df-cnv 4542 df-co 4543 df-dm 4544 df-rn 4545 df-res 4546 df-ima 4547 df-iota 5083 df-fun 5120 df-fn 5121 df-fv 5126 |
This theorem is referenced by: funimass3 5529 elpreima 5532 fisumss 11154 |
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