Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
||
Mirrors > Home > MPE Home > Th. List > dfss2 | Structured version Visualization version GIF version |
Description: Alternate definition of the subclass relationship between two classes. Definition 5.9 of [TakeutiZaring] p. 17. (Contributed by NM, 8-Jan-2002.) |
Ref | Expression |
---|---|
dfss2 | ⊢ (𝐴 ⊆ 𝐵 ↔ ∀𝑥(𝑥 ∈ 𝐴 → 𝑥 ∈ 𝐵)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dfss 3956 | . . 3 ⊢ (𝐴 ⊆ 𝐵 ↔ 𝐴 = (𝐴 ∩ 𝐵)) | |
2 | df-in 3946 | . . . 4 ⊢ (𝐴 ∩ 𝐵) = {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝑥 ∈ 𝐵)} | |
3 | 2 | eqeq2i 2837 | . . 3 ⊢ (𝐴 = (𝐴 ∩ 𝐵) ↔ 𝐴 = {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝑥 ∈ 𝐵)}) |
4 | abeq2 2948 | . . 3 ⊢ (𝐴 = {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝑥 ∈ 𝐵)} ↔ ∀𝑥(𝑥 ∈ 𝐴 ↔ (𝑥 ∈ 𝐴 ∧ 𝑥 ∈ 𝐵))) | |
5 | 1, 3, 4 | 3bitri 299 | . 2 ⊢ (𝐴 ⊆ 𝐵 ↔ ∀𝑥(𝑥 ∈ 𝐴 ↔ (𝑥 ∈ 𝐴 ∧ 𝑥 ∈ 𝐵))) |
6 | pm4.71 560 | . . 3 ⊢ ((𝑥 ∈ 𝐴 → 𝑥 ∈ 𝐵) ↔ (𝑥 ∈ 𝐴 ↔ (𝑥 ∈ 𝐴 ∧ 𝑥 ∈ 𝐵))) | |
7 | 6 | albii 1819 | . 2 ⊢ (∀𝑥(𝑥 ∈ 𝐴 → 𝑥 ∈ 𝐵) ↔ ∀𝑥(𝑥 ∈ 𝐴 ↔ (𝑥 ∈ 𝐴 ∧ 𝑥 ∈ 𝐵))) |
8 | 5, 7 | bitr4i 280 | 1 ⊢ (𝐴 ⊆ 𝐵 ↔ ∀𝑥(𝑥 ∈ 𝐴 → 𝑥 ∈ 𝐵)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 208 ∧ wa 398 ∀wal 1534 = wceq 1536 ∈ wcel 2113 {cab 2802 ∩ cin 3938 ⊆ wss 3939 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1795 ax-4 1809 ax-5 1910 ax-6 1969 ax-7 2014 ax-8 2115 ax-9 2123 ax-10 2144 ax-11 2160 ax-12 2176 ax-ext 2796 |
This theorem depends on definitions: df-bi 209 df-an 399 df-or 844 df-tru 1539 df-ex 1780 df-nf 1784 df-sb 2069 df-clab 2803 df-cleq 2817 df-clel 2896 df-in 3946 df-ss 3955 |
This theorem is referenced by: dfss3 3959 dfss6 3960 dfss2f 3961 ssel 3964 ssriv 3974 ssrdv 3976 sstr2 3977 eqss 3985 nss 4032 rabss2 4057 ssconb 4117 ssequn1 4159 unss 4163 ssin 4210 ssdif0 4326 difin0ss 4331 inssdif0 4332 reldisj 4405 ssundif 4436 sbcssg 4466 pwss 4567 snssg 4720 pwpw0 4749 pwsnOLD 4834 ssuni 4866 unissb 4873 iunss 4972 dftr2 5177 axpweq 5268 axpow2 5271 ssextss 5349 ssrel 5660 ssrel2 5662 ssrelrel 5672 reliun 5692 relop 5724 idrefALT 5976 funimass4 6733 dfom2 7585 inf2 9089 grothprim 10259 psslinpr 10456 ltaddpr 10459 isprm2 16029 vdwmc2 16318 acsmapd 17791 dfconn2 22030 iskgen3 22160 metcld 23912 metcld2 23913 isch2 29003 pjnormssi 29948 ssiun3 30313 ssrelf 30369 bnj1361 32104 bnj978 32225 dffr5 32993 brsset 33354 sscoid 33378 relowlpssretop 34649 fvineqsneq 34697 rp-fakeinunass 39887 rababg 39939 ss2iundf 40010 dfhe3 40127 snhesn 40138 dffrege76 40291 ntrneiiso 40447 ntrneik2 40448 ntrneix2 40449 ntrneikb 40450 expanduniss 40635 ismnuprim 40636 onfrALTlem2 40886 trsspwALT 41158 trsspwALT2 41159 snssiALTVD 41167 snssiALT 41168 sstrALT2VD 41174 sstrALT2 41175 sbcssgVD 41223 onfrALTlem2VD 41229 sspwimp 41258 sspwimpVD 41259 sspwimpcf 41260 sspwimpcfVD 41261 sspwimpALT 41265 unisnALT 41266 iunssf 41358 icccncfext 42176 |
Copyright terms: Public domain | W3C validator |