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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 5399 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 5749 | . . . . 5 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → 〈𝐴, (𝐹‘𝐴)〉 ∈ 𝐹) | |
| 2 | funfvex 5646 | . . . . . 6 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → (𝐹‘𝐴) ∈ V) | |
| 3 | opelcnvg 4902 | . . . . . 6 ⊢ (((𝐹‘𝐴) ∈ V ∧ 𝐴 ∈ dom 𝐹) → (〈(𝐹‘𝐴), 𝐴〉 ∈ ◡𝐹 ↔ 〈𝐴, (𝐹‘𝐴)〉 ∈ 𝐹)) | |
| 4 | 2, 3 | sylancom 420 | . . . . 5 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → (〈(𝐹‘𝐴), 𝐴〉 ∈ ◡𝐹 ↔ 〈𝐴, (𝐹‘𝐴)〉 ∈ 𝐹)) |
| 5 | 1, 4 | mpbird 167 | . . . 4 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → 〈(𝐹‘𝐴), 𝐴〉 ∈ ◡𝐹) |
| 6 | elimasng 5096 | . . . . 5 ⊢ (((𝐹‘𝐴) ∈ V ∧ 𝐴 ∈ dom 𝐹) → (𝐴 ∈ (◡𝐹 “ {(𝐹‘𝐴)}) ↔ 〈(𝐹‘𝐴), 𝐴〉 ∈ ◡𝐹)) | |
| 7 | 2, 6 | sylancom 420 | . . . 4 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → (𝐴 ∈ (◡𝐹 “ {(𝐹‘𝐴)}) ↔ 〈(𝐹‘𝐴), 𝐴〉 ∈ ◡𝐹)) |
| 8 | 5, 7 | mpbird 167 | . . 3 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → 𝐴 ∈ (◡𝐹 “ {(𝐹‘𝐴)})) |
| 9 | snssg 3802 | . . . . . . . 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 5104 | . . . . . . 7 ⊢ ({(𝐹‘𝐴)} ⊆ 𝐵 → (◡𝐹 “ {(𝐹‘𝐴)}) ⊆ (◡𝐹 “ 𝐵)) | |
| 12 | 10, 11 | biimtrdi 163 | . . . . . 6 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → ((𝐹‘𝐴) ∈ 𝐵 → (◡𝐹 “ {(𝐹‘𝐴)}) ⊆ (◡𝐹 “ 𝐵))) |
| 13 | 12 | imp 124 | . . . . 5 ⊢ (((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) ∧ (𝐹‘𝐴) ∈ 𝐵) → (◡𝐹 “ {(𝐹‘𝐴)}) ⊆ (◡𝐹 “ 𝐵)) |
| 14 | 13 | sseld 3223 | . . . 4 ⊢ (((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) ∧ (𝐹‘𝐴) ∈ 𝐵) → (𝐴 ∈ (◡𝐹 “ {(𝐹‘𝐴)}) → 𝐴 ∈ (◡𝐹 “ 𝐵))) |
| 15 | 14 | ex 115 | . . 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 5751 | . . . 4 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ (◡𝐹 “ 𝐵)) → (𝐹‘𝐴) ∈ 𝐵) | |
| 18 | 17 | ex 115 | . . 3 ⊢ (Fun 𝐹 → (𝐴 ∈ (◡𝐹 “ 𝐵) → (𝐹‘𝐴) ∈ 𝐵)) |
| 19 | 18 | adantr 276 | . 2 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → (𝐴 ∈ (◡𝐹 “ 𝐵) → (𝐹‘𝐴) ∈ 𝐵)) |
| 20 | 16, 19 | impbid 129 | 1 ⊢ ((Fun 𝐹 ∧ 𝐴 ∈ dom 𝐹) → ((𝐹‘𝐴) ∈ 𝐵 ↔ 𝐴 ∈ (◡𝐹 “ 𝐵))) |
| Colors of variables: wff set class |
| Syntax hints: → wi 4 ∧ wa 104 ↔ wb 105 ∈ wcel 2200 Vcvv 2799 ⊆ wss 3197 {csn 3666 〈cop 3669 ◡ccnv 4718 dom cdm 4719 “ cima 4722 Fun wfun 5312 ‘cfv 5318 |
| 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-sbc 3029 df-un 3201 df-in 3203 df-ss 3210 df-pw 3651 df-sn 3672 df-pr 3673 df-op 3675 df-uni 3889 df-br 4084 df-opab 4146 df-id 4384 df-xp 4725 df-rel 4726 df-cnv 4727 df-co 4728 df-dm 4729 df-rn 4730 df-res 4731 df-ima 4732 df-iota 5278 df-fun 5320 df-fn 5321 df-fv 5326 |
| This theorem is referenced by: funimass3 5753 elpreima 5756 fisumss 11911 psrbaglesuppg 14644 |
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