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Mirrors > Home > MPE Home > Th. List > Mathboxes > fnessex | Structured version Visualization version GIF version |
Description: If 𝐵 is finer than 𝐴 and 𝑆 is an element of 𝐴, every point in 𝑆 is an element of a subset of 𝑆 which is in 𝐵. (Contributed by Jeff Hankins, 28-Sep-2009.) |
Ref | Expression |
---|---|
fnessex | ⊢ ((𝐴Fne𝐵 ∧ 𝑆 ∈ 𝐴 ∧ 𝑃 ∈ 𝑆) → ∃𝑥 ∈ 𝐵 (𝑃 ∈ 𝑥 ∧ 𝑥 ⊆ 𝑆)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | fnetg 33247 | . . 3 ⊢ (𝐴Fne𝐵 → 𝐴 ⊆ (topGen‘𝐵)) | |
2 | 1 | sselda 3853 | . 2 ⊢ ((𝐴Fne𝐵 ∧ 𝑆 ∈ 𝐴) → 𝑆 ∈ (topGen‘𝐵)) |
3 | tg2 21293 | . 2 ⊢ ((𝑆 ∈ (topGen‘𝐵) ∧ 𝑃 ∈ 𝑆) → ∃𝑥 ∈ 𝐵 (𝑃 ∈ 𝑥 ∧ 𝑥 ⊆ 𝑆)) | |
4 | 2, 3 | stoic3 1740 | 1 ⊢ ((𝐴Fne𝐵 ∧ 𝑆 ∈ 𝐴 ∧ 𝑃 ∈ 𝑆) → ∃𝑥 ∈ 𝐵 (𝑃 ∈ 𝑥 ∧ 𝑥 ⊆ 𝑆)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 387 ∧ w3a 1069 ∈ wcel 2051 ∃wrex 3084 ⊆ wss 3824 class class class wbr 4926 ‘cfv 6186 topGenctg 16566 Fnecfne 33238 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1759 ax-4 1773 ax-5 1870 ax-6 1929 ax-7 1966 ax-8 2053 ax-9 2060 ax-10 2080 ax-11 2094 ax-12 2107 ax-13 2302 ax-ext 2745 ax-sep 5057 ax-nul 5064 ax-pow 5116 ax-pr 5183 ax-un 7278 |
This theorem depends on definitions: df-bi 199 df-an 388 df-or 835 df-3an 1071 df-tru 1511 df-ex 1744 df-nf 1748 df-sb 2017 df-mo 2548 df-eu 2585 df-clab 2754 df-cleq 2766 df-clel 2841 df-nfc 2913 df-ral 3088 df-rex 3089 df-rab 3092 df-v 3412 df-sbc 3677 df-dif 3827 df-un 3829 df-in 3831 df-ss 3838 df-nul 4174 df-if 4346 df-pw 4419 df-sn 4437 df-pr 4439 df-op 4443 df-uni 4710 df-br 4927 df-opab 4989 df-mpt 5006 df-id 5309 df-xp 5410 df-rel 5411 df-cnv 5412 df-co 5413 df-dm 5414 df-iota 6150 df-fun 6188 df-fv 6194 df-topgen 16572 df-fne 33239 |
This theorem is referenced by: fneint 33250 fnessref 33259 |
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