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Mirrors > Home > NFE Home > Th. List > fvimacnv | GIF version |
Description: The argument of a function value belongs to the preimage of any class containing the function value. (Contributed by Raph Levien, 20-Nov-2006.) He remarks: "This proof is unsatisfying, because it seems to me that funimass2 5171 could probably be strengthened to a biconditional." |
Ref | Expression |
---|---|
fvimacnv | ⊢ ((Fun F ∧ A ∈ dom F) → ((F ‘A) ∈ B ↔ A ∈ (◡F “ B))) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | funfvop 5401 | . . . . 5 ⊢ ((Fun F ∧ A ∈ dom F) → 〈A, (F ‘A)〉 ∈ F) | |
2 | opelcnv 4894 | . . . . 5 ⊢ (〈(F ‘A), A〉 ∈ ◡F ↔ 〈A, (F ‘A)〉 ∈ F) | |
3 | 1, 2 | sylibr 203 | . . . 4 ⊢ ((Fun F ∧ A ∈ dom F) → 〈(F ‘A), A〉 ∈ ◡F) |
4 | elimasn 5020 | . . . 4 ⊢ (A ∈ (◡F “ {(F ‘A)}) ↔ 〈(F ‘A), A〉 ∈ ◡F) | |
5 | 3, 4 | sylibr 203 | . . 3 ⊢ ((Fun F ∧ A ∈ dom F) → A ∈ (◡F “ {(F ‘A)})) |
6 | fvex 5340 | . . . . . 6 ⊢ (F ‘A) ∈ V | |
7 | 6 | snss 3839 | . . . . 5 ⊢ ((F ‘A) ∈ B ↔ {(F ‘A)} ⊆ B) |
8 | imass2 5025 | . . . . 5 ⊢ ({(F ‘A)} ⊆ B → (◡F “ {(F ‘A)}) ⊆ (◡F “ B)) | |
9 | 7, 8 | sylbi 187 | . . . 4 ⊢ ((F ‘A) ∈ B → (◡F “ {(F ‘A)}) ⊆ (◡F “ B)) |
10 | 9 | sseld 3273 | . . 3 ⊢ ((F ‘A) ∈ B → (A ∈ (◡F “ {(F ‘A)}) → A ∈ (◡F “ B))) |
11 | 5, 10 | syl5com 26 | . 2 ⊢ ((Fun F ∧ A ∈ dom F) → ((F ‘A) ∈ B → A ∈ (◡F “ B))) |
12 | fvimacnvi 5403 | . . . 4 ⊢ ((Fun F ∧ A ∈ (◡F “ B)) → (F ‘A) ∈ B) | |
13 | 12 | ex 423 | . . 3 ⊢ (Fun F → (A ∈ (◡F “ B) → (F ‘A) ∈ B)) |
14 | 13 | adantr 451 | . 2 ⊢ ((Fun F ∧ A ∈ dom F) → (A ∈ (◡F “ B) → (F ‘A) ∈ B)) |
15 | 11, 14 | impbid 183 | 1 ⊢ ((Fun F ∧ A ∈ dom F) → ((F ‘A) ∈ B ↔ A ∈ (◡F “ B))) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 176 ∧ wa 358 ∈ wcel 1710 ⊆ wss 3258 {csn 3738 〈cop 4562 “ cima 4723 ◡ccnv 4772 dom cdm 4773 Fun wfun 4776 ‘cfv 4782 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1546 ax-5 1557 ax-17 1616 ax-9 1654 ax-8 1675 ax-13 1712 ax-14 1714 ax-6 1729 ax-7 1734 ax-11 1746 ax-12 1925 ax-ext 2334 ax-nin 4079 ax-xp 4080 ax-cnv 4081 ax-1c 4082 ax-sset 4083 ax-si 4084 ax-ins2 4085 ax-ins3 4086 ax-typlower 4087 ax-sn 4088 |
This theorem depends on definitions: df-bi 177 df-or 359 df-an 360 df-3or 935 df-3an 936 df-nan 1288 df-tru 1319 df-ex 1542 df-nf 1545 df-sb 1649 df-eu 2208 df-mo 2209 df-clab 2340 df-cleq 2346 df-clel 2349 df-nfc 2479 df-ne 2519 df-ral 2620 df-rex 2621 df-reu 2622 df-rmo 2623 df-rab 2624 df-v 2862 df-sbc 3048 df-nin 3212 df-compl 3213 df-in 3214 df-un 3215 df-dif 3216 df-symdif 3217 df-ss 3260 df-pss 3262 df-nul 3552 df-if 3664 df-pw 3725 df-sn 3742 df-pr 3743 df-uni 3893 df-int 3928 df-opk 4059 df-1c 4137 df-pw1 4138 df-uni1 4139 df-xpk 4186 df-cnvk 4187 df-ins2k 4188 df-ins3k 4189 df-imak 4190 df-cok 4191 df-p6 4192 df-sik 4193 df-ssetk 4194 df-imagek 4195 df-idk 4196 df-iota 4340 df-0c 4378 df-addc 4379 df-nnc 4380 df-fin 4381 df-lefin 4441 df-ltfin 4442 df-ncfin 4443 df-tfin 4444 df-evenfin 4445 df-oddfin 4446 df-sfin 4447 df-spfin 4448 df-phi 4566 df-op 4567 df-proj1 4568 df-proj2 4569 df-opab 4624 df-br 4641 df-co 4727 df-ima 4728 df-id 4768 df-xp 4785 df-cnv 4786 df-rn 4787 df-dm 4788 df-res 4789 df-fun 4790 df-fn 4791 df-fv 4796 |
This theorem is referenced by: funimass3 5405 elpreima 5408 |
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