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Mirrors > Home > ILE Home > Th. List > ssel | GIF version |
Description: Membership relationships follow from a subclass relationship. (Contributed by NM, 5-Aug-1993.) |
Ref | Expression |
---|---|
ssel | ⊢ (𝐴 ⊆ 𝐵 → (𝐶 ∈ 𝐴 → 𝐶 ∈ 𝐵)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dfss2 3136 | . . . . . 6 ⊢ (𝐴 ⊆ 𝐵 ↔ ∀𝑥(𝑥 ∈ 𝐴 → 𝑥 ∈ 𝐵)) | |
2 | 1 | biimpi 119 | . . . . 5 ⊢ (𝐴 ⊆ 𝐵 → ∀𝑥(𝑥 ∈ 𝐴 → 𝑥 ∈ 𝐵)) |
3 | 2 | 19.21bi 1551 | . . . 4 ⊢ (𝐴 ⊆ 𝐵 → (𝑥 ∈ 𝐴 → 𝑥 ∈ 𝐵)) |
4 | 3 | anim2d 335 | . . 3 ⊢ (𝐴 ⊆ 𝐵 → ((𝑥 = 𝐶 ∧ 𝑥 ∈ 𝐴) → (𝑥 = 𝐶 ∧ 𝑥 ∈ 𝐵))) |
5 | 4 | eximdv 1873 | . 2 ⊢ (𝐴 ⊆ 𝐵 → (∃𝑥(𝑥 = 𝐶 ∧ 𝑥 ∈ 𝐴) → ∃𝑥(𝑥 = 𝐶 ∧ 𝑥 ∈ 𝐵))) |
6 | df-clel 2166 | . 2 ⊢ (𝐶 ∈ 𝐴 ↔ ∃𝑥(𝑥 = 𝐶 ∧ 𝑥 ∈ 𝐴)) | |
7 | df-clel 2166 | . 2 ⊢ (𝐶 ∈ 𝐵 ↔ ∃𝑥(𝑥 = 𝐶 ∧ 𝑥 ∈ 𝐵)) | |
8 | 5, 6, 7 | 3imtr4g 204 | 1 ⊢ (𝐴 ⊆ 𝐵 → (𝐶 ∈ 𝐴 → 𝐶 ∈ 𝐵)) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 103 ∀wal 1346 = wceq 1348 ∃wex 1485 ∈ wcel 2141 ⊆ wss 3121 |
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-5 1440 ax-7 1441 ax-gen 1442 ax-ie1 1486 ax-ie2 1487 ax-8 1497 ax-11 1499 ax-4 1503 ax-17 1519 ax-i9 1523 ax-ial 1527 ax-i5r 1528 ax-ext 2152 |
This theorem depends on definitions: df-bi 116 df-nf 1454 df-sb 1756 df-clab 2157 df-cleq 2163 df-clel 2166 df-in 3127 df-ss 3134 |
This theorem is referenced by: ssel2 3142 sseli 3143 sseld 3146 sstr2 3154 nelss 3208 ssrexf 3209 ssralv 3211 ssrexv 3212 ralss 3213 rexss 3214 ssconb 3260 sscon 3261 ssdif 3262 unss1 3296 ssrin 3352 difin2 3389 reuss2 3407 reupick 3411 sssnm 3741 uniss 3817 ss2iun 3888 ssiun 3915 iinss 3924 disjss2 3969 disjss1 3972 pwnss 4145 sspwb 4201 ssopab2b 4261 soss 4299 sucssel 4409 ssorduni 4471 onintonm 4501 onnmin 4552 ssnel 4553 wessep 4562 ssrel 4699 ssrel2 4701 ssrelrel 4711 xpss12 4718 cnvss 4784 dmss 4810 elreldm 4837 dmcosseq 4882 relssres 4929 iss 4937 resopab2 4938 issref 4993 ssrnres 5053 dfco2a 5111 cores 5114 funssres 5240 fununi 5266 funimaexglem 5281 dfimafn 5545 funimass4 5547 funimass3 5612 dff4im 5642 funfvima2 5728 funfvima3 5729 f1elima 5752 riotass2 5835 ssoprab2b 5910 resoprab2 5950 releldm2 6164 reldmtpos 6232 dmtpos 6235 rdgss 6362 ss2ixp 6689 fiintim 6906 negf1o 8301 lbreu 8861 lbinf 8864 eqreznegel 9573 negm 9574 iccsupr 9923 negfi 11191 sumrbdclem 11340 prodrbdclem 11534 fprodmodd 11604 metrest 13300 bdop 13910 bj-nnen2lp 13989 exmidsbthrlem 14054 |
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