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Description: A line is a projective subspace. (Contributed by NM, 16-Oct-2011) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | linepsub.n | |- N = ( Lines ` K ) |
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| linepsub.s | |- S = ( PSubSp ` K ) |
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| Assertion | linepsubN | |- ( ( K e. Lat /\ X e. N ) -> X e. S ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | linepsub.n | |- N = ( Lines ` K ) |
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| 2 | linepsub.s | |- S = ( PSubSp ` K ) |
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| 3 | ssrab2 | |- { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } C_ ( Atoms ` K ) |
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| 4 | sseq1 | |- ( X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } -> ( X C_ ( Atoms ` K ) <-> { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } C_ ( Atoms ` K ) ) ) |
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| 5 | 3 4 | mpbiri | |- ( X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } -> X C_ ( Atoms ` K ) ) |
| 6 | 5 | a1i | |- ( ( K e. Lat /\ ( a e. ( Atoms ` K ) /\ b e. ( Atoms ` K ) ) ) -> ( X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } -> X C_ ( Atoms ` K ) ) ) |
| 7 | eqid | |- ( Base ` K ) = ( Base ` K ) |
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| 8 | eqid | |- ( Atoms ` K ) = ( Atoms ` K ) |
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| 9 | 7 8 | atbase | |- ( a e. ( Atoms ` K ) -> a e. ( Base ` K ) ) |
| 10 | 7 8 | atbase | |- ( b e. ( Atoms ` K ) -> b e. ( Base ` K ) ) |
| 11 | 9 10 | anim12i | |- ( ( a e. ( Atoms ` K ) /\ b e. ( Atoms ` K ) ) -> ( a e. ( Base ` K ) /\ b e. ( Base ` K ) ) ) |
| 12 | eqid | |- ( join ` K ) = ( join ` K ) |
|
| 13 | 7 12 | latjcl | |- ( ( K e. Lat /\ a e. ( Base ` K ) /\ b e. ( Base ` K ) ) -> ( a ( join ` K ) b ) e. ( Base ` K ) ) |
| 14 | 13 | 3expb | |- ( ( K e. Lat /\ ( a e. ( Base ` K ) /\ b e. ( Base ` K ) ) ) -> ( a ( join ` K ) b ) e. ( Base ` K ) ) |
| 15 | 11 14 | sylan2 | |- ( ( K e. Lat /\ ( a e. ( Atoms ` K ) /\ b e. ( Atoms ` K ) ) ) -> ( a ( join ` K ) b ) e. ( Base ` K ) ) |
| 16 | eleq2 | |- ( X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } -> ( p e. X <-> p e. { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } ) ) |
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| 17 | breq1 | |- ( c = p -> ( c ( le ` K ) ( a ( join ` K ) b ) <-> p ( le ` K ) ( a ( join ` K ) b ) ) ) |
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| 18 | 17 | elrab | |- ( p e. { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } <-> ( p e. ( Atoms ` K ) /\ p ( le ` K ) ( a ( join ` K ) b ) ) ) |
| 19 | 7 8 | atbase | |- ( p e. ( Atoms ` K ) -> p e. ( Base ` K ) ) |
| 20 | 19 | anim1i | |- ( ( p e. ( Atoms ` K ) /\ p ( le ` K ) ( a ( join ` K ) b ) ) -> ( p e. ( Base ` K ) /\ p ( le ` K ) ( a ( join ` K ) b ) ) ) |
| 21 | 18 20 | sylbi | |- ( p e. { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } -> ( p e. ( Base ` K ) /\ p ( le ` K ) ( a ( join ` K ) b ) ) ) |
| 22 | 16 21 | biimtrdi | |- ( X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } -> ( p e. X -> ( p e. ( Base ` K ) /\ p ( le ` K ) ( a ( join ` K ) b ) ) ) ) |
| 23 | eleq2 | |- ( X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } -> ( q e. X <-> q e. { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } ) ) |
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| 24 | breq1 | |- ( c = q -> ( c ( le ` K ) ( a ( join ` K ) b ) <-> q ( le ` K ) ( a ( join ` K ) b ) ) ) |
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| 25 | 24 | elrab | |- ( q e. { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } <-> ( q e. ( Atoms ` K ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) ) |
| 26 | 7 8 | atbase | |- ( q e. ( Atoms ` K ) -> q e. ( Base ` K ) ) |
| 27 | 26 | anim1i | |- ( ( q e. ( Atoms ` K ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) -> ( q e. ( Base ` K ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) ) |
| 28 | 25 27 | sylbi | |- ( q e. { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } -> ( q e. ( Base ` K ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) ) |
| 29 | 23 28 | biimtrdi | |- ( X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } -> ( q e. X -> ( q e. ( Base ` K ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) ) ) |
| 30 | 22 29 | anim12d | |- ( X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } -> ( ( p e. X /\ q e. X ) -> ( ( p e. ( Base ` K ) /\ p ( le ` K ) ( a ( join ` K ) b ) ) /\ ( q e. ( Base ` K ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) ) ) ) |
| 31 | an4 | |- ( ( ( p e. ( Base ` K ) /\ p ( le ` K ) ( a ( join ` K ) b ) ) /\ ( q e. ( Base ` K ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) ) <-> ( ( p e. ( Base ` K ) /\ q e. ( Base ` K ) ) /\ ( p ( le ` K ) ( a ( join ` K ) b ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) ) ) |
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| 32 | 30 31 | imbitrdi | |- ( X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } -> ( ( p e. X /\ q e. X ) -> ( ( p e. ( Base ` K ) /\ q e. ( Base ` K ) ) /\ ( p ( le ` K ) ( a ( join ` K ) b ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) ) ) ) |
| 33 | 32 | imp | |- ( ( X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } /\ ( p e. X /\ q e. X ) ) -> ( ( p e. ( Base ` K ) /\ q e. ( Base ` K ) ) /\ ( p ( le ` K ) ( a ( join ` K ) b ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) ) ) |
| 34 | 33 | anim2i | |- ( ( ( K e. Lat /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) /\ ( X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } /\ ( p e. X /\ q e. X ) ) ) -> ( ( K e. Lat /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) /\ ( ( p e. ( Base ` K ) /\ q e. ( Base ` K ) ) /\ ( p ( le ` K ) ( a ( join ` K ) b ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) ) ) ) |
| 35 | 34 | anassrs | |- ( ( ( ( K e. Lat /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) /\ X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } ) /\ ( p e. X /\ q e. X ) ) -> ( ( K e. Lat /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) /\ ( ( p e. ( Base ` K ) /\ q e. ( Base ` K ) ) /\ ( p ( le ` K ) ( a ( join ` K ) b ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) ) ) ) |
| 36 | 7 8 | atbase | |- ( r e. ( Atoms ` K ) -> r e. ( Base ` K ) ) |
| 37 | eqid | |- ( le ` K ) = ( le ` K ) |
|
| 38 | 7 37 12 | latjle12 | |- ( ( K e. Lat /\ ( p e. ( Base ` K ) /\ q e. ( Base ` K ) /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) ) -> ( ( p ( le ` K ) ( a ( join ` K ) b ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) <-> ( p ( join ` K ) q ) ( le ` K ) ( a ( join ` K ) b ) ) ) |
| 39 | 38 | biimpd | |- ( ( K e. Lat /\ ( p e. ( Base ` K ) /\ q e. ( Base ` K ) /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) ) -> ( ( p ( le ` K ) ( a ( join ` K ) b ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) -> ( p ( join ` K ) q ) ( le ` K ) ( a ( join ` K ) b ) ) ) |
| 40 | 39 | 3exp2 | |- ( K e. Lat -> ( p e. ( Base ` K ) -> ( q e. ( Base ` K ) -> ( ( a ( join ` K ) b ) e. ( Base ` K ) -> ( ( p ( le ` K ) ( a ( join ` K ) b ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) -> ( p ( join ` K ) q ) ( le ` K ) ( a ( join ` K ) b ) ) ) ) ) ) |
| 41 | 40 | impd | |- ( K e. Lat -> ( ( p e. ( Base ` K ) /\ q e. ( Base ` K ) ) -> ( ( a ( join ` K ) b ) e. ( Base ` K ) -> ( ( p ( le ` K ) ( a ( join ` K ) b ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) -> ( p ( join ` K ) q ) ( le ` K ) ( a ( join ` K ) b ) ) ) ) ) |
| 42 | 41 | com23 | |- ( K e. Lat -> ( ( a ( join ` K ) b ) e. ( Base ` K ) -> ( ( p e. ( Base ` K ) /\ q e. ( Base ` K ) ) -> ( ( p ( le ` K ) ( a ( join ` K ) b ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) -> ( p ( join ` K ) q ) ( le ` K ) ( a ( join ` K ) b ) ) ) ) ) |
| 43 | 42 | imp43 | |- ( ( ( K e. Lat /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) /\ ( ( p e. ( Base ` K ) /\ q e. ( Base ` K ) ) /\ ( p ( le ` K ) ( a ( join ` K ) b ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) ) ) -> ( p ( join ` K ) q ) ( le ` K ) ( a ( join ` K ) b ) ) |
| 44 | 43 | adantr | |- ( ( ( ( K e. Lat /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) /\ ( ( p e. ( Base ` K ) /\ q e. ( Base ` K ) ) /\ ( p ( le ` K ) ( a ( join ` K ) b ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) ) ) /\ r e. ( Base ` K ) ) -> ( p ( join ` K ) q ) ( le ` K ) ( a ( join ` K ) b ) ) |
| 45 | 7 12 | latjcl | |- ( ( K e. Lat /\ p e. ( Base ` K ) /\ q e. ( Base ` K ) ) -> ( p ( join ` K ) q ) e. ( Base ` K ) ) |
| 46 | 45 | 3expib | |- ( K e. Lat -> ( ( p e. ( Base ` K ) /\ q e. ( Base ` K ) ) -> ( p ( join ` K ) q ) e. ( Base ` K ) ) ) |
| 47 | 7 37 | lattr | |- ( ( K e. Lat /\ ( r e. ( Base ` K ) /\ ( p ( join ` K ) q ) e. ( Base ` K ) /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) ) -> ( ( r ( le ` K ) ( p ( join ` K ) q ) /\ ( p ( join ` K ) q ) ( le ` K ) ( a ( join ` K ) b ) ) -> r ( le ` K ) ( a ( join ` K ) b ) ) ) |
| 48 | 47 | 3exp2 | |- ( K e. Lat -> ( r e. ( Base ` K ) -> ( ( p ( join ` K ) q ) e. ( Base ` K ) -> ( ( a ( join ` K ) b ) e. ( Base ` K ) -> ( ( r ( le ` K ) ( p ( join ` K ) q ) /\ ( p ( join ` K ) q ) ( le ` K ) ( a ( join ` K ) b ) ) -> r ( le ` K ) ( a ( join ` K ) b ) ) ) ) ) ) |
| 49 | 48 | com24 | |- ( K e. Lat -> ( ( a ( join ` K ) b ) e. ( Base ` K ) -> ( ( p ( join ` K ) q ) e. ( Base ` K ) -> ( r e. ( Base ` K ) -> ( ( r ( le ` K ) ( p ( join ` K ) q ) /\ ( p ( join ` K ) q ) ( le ` K ) ( a ( join ` K ) b ) ) -> r ( le ` K ) ( a ( join ` K ) b ) ) ) ) ) ) |
| 50 | 46 49 | syl5d | |- ( K e. Lat -> ( ( a ( join ` K ) b ) e. ( Base ` K ) -> ( ( p e. ( Base ` K ) /\ q e. ( Base ` K ) ) -> ( r e. ( Base ` K ) -> ( ( r ( le ` K ) ( p ( join ` K ) q ) /\ ( p ( join ` K ) q ) ( le ` K ) ( a ( join ` K ) b ) ) -> r ( le ` K ) ( a ( join ` K ) b ) ) ) ) ) ) |
| 51 | 50 | imp41 | |- ( ( ( ( K e. Lat /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) /\ ( p e. ( Base ` K ) /\ q e. ( Base ` K ) ) ) /\ r e. ( Base ` K ) ) -> ( ( r ( le ` K ) ( p ( join ` K ) q ) /\ ( p ( join ` K ) q ) ( le ` K ) ( a ( join ` K ) b ) ) -> r ( le ` K ) ( a ( join ` K ) b ) ) ) |
| 52 | 51 | adantlrr | |- ( ( ( ( K e. Lat /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) /\ ( ( p e. ( Base ` K ) /\ q e. ( Base ` K ) ) /\ ( p ( le ` K ) ( a ( join ` K ) b ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) ) ) /\ r e. ( Base ` K ) ) -> ( ( r ( le ` K ) ( p ( join ` K ) q ) /\ ( p ( join ` K ) q ) ( le ` K ) ( a ( join ` K ) b ) ) -> r ( le ` K ) ( a ( join ` K ) b ) ) ) |
| 53 | 44 52 | mpan2d | |- ( ( ( ( K e. Lat /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) /\ ( ( p e. ( Base ` K ) /\ q e. ( Base ` K ) ) /\ ( p ( le ` K ) ( a ( join ` K ) b ) /\ q ( le ` K ) ( a ( join ` K ) b ) ) ) ) /\ r e. ( Base ` K ) ) -> ( r ( le ` K ) ( p ( join ` K ) q ) -> r ( le ` K ) ( a ( join ` K ) b ) ) ) |
| 54 | 35 36 53 | syl2an | |- ( ( ( ( ( K e. Lat /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) /\ X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } ) /\ ( p e. X /\ q e. X ) ) /\ r e. ( Atoms ` K ) ) -> ( r ( le ` K ) ( p ( join ` K ) q ) -> r ( le ` K ) ( a ( join ` K ) b ) ) ) |
| 55 | simpr | |- ( ( ( ( ( K e. Lat /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) /\ X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } ) /\ ( p e. X /\ q e. X ) ) /\ r e. ( Atoms ` K ) ) -> r e. ( Atoms ` K ) ) |
|
| 56 | 54 55 | jctild | |- ( ( ( ( ( K e. Lat /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) /\ X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } ) /\ ( p e. X /\ q e. X ) ) /\ r e. ( Atoms ` K ) ) -> ( r ( le ` K ) ( p ( join ` K ) q ) -> ( r e. ( Atoms ` K ) /\ r ( le ` K ) ( a ( join ` K ) b ) ) ) ) |
| 57 | eleq2 | |- ( X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } -> ( r e. X <-> r e. { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } ) ) |
|
| 58 | breq1 | |- ( c = r -> ( c ( le ` K ) ( a ( join ` K ) b ) <-> r ( le ` K ) ( a ( join ` K ) b ) ) ) |
|
| 59 | 58 | elrab | |- ( r e. { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } <-> ( r e. ( Atoms ` K ) /\ r ( le ` K ) ( a ( join ` K ) b ) ) ) |
| 60 | 57 59 | bitrdi | |- ( X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } -> ( r e. X <-> ( r e. ( Atoms ` K ) /\ r ( le ` K ) ( a ( join ` K ) b ) ) ) ) |
| 61 | 60 | ad3antlr | |- ( ( ( ( ( K e. Lat /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) /\ X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } ) /\ ( p e. X /\ q e. X ) ) /\ r e. ( Atoms ` K ) ) -> ( r e. X <-> ( r e. ( Atoms ` K ) /\ r ( le ` K ) ( a ( join ` K ) b ) ) ) ) |
| 62 | 56 61 | sylibrd | |- ( ( ( ( ( K e. Lat /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) /\ X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } ) /\ ( p e. X /\ q e. X ) ) /\ r e. ( Atoms ` K ) ) -> ( r ( le ` K ) ( p ( join ` K ) q ) -> r e. X ) ) |
| 63 | 62 | ralrimiva | |- ( ( ( ( K e. Lat /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) /\ X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } ) /\ ( p e. X /\ q e. X ) ) -> A. r e. ( Atoms ` K ) ( r ( le ` K ) ( p ( join ` K ) q ) -> r e. X ) ) |
| 64 | 63 | ralrimivva | |- ( ( ( K e. Lat /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) /\ X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } ) -> A. p e. X A. q e. X A. r e. ( Atoms ` K ) ( r ( le ` K ) ( p ( join ` K ) q ) -> r e. X ) ) |
| 65 | 64 | ex | |- ( ( K e. Lat /\ ( a ( join ` K ) b ) e. ( Base ` K ) ) -> ( X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } -> A. p e. X A. q e. X A. r e. ( Atoms ` K ) ( r ( le ` K ) ( p ( join ` K ) q ) -> r e. X ) ) ) |
| 66 | 15 65 | syldan | |- ( ( K e. Lat /\ ( a e. ( Atoms ` K ) /\ b e. ( Atoms ` K ) ) ) -> ( X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } -> A. p e. X A. q e. X A. r e. ( Atoms ` K ) ( r ( le ` K ) ( p ( join ` K ) q ) -> r e. X ) ) ) |
| 67 | 6 66 | jcad | |- ( ( K e. Lat /\ ( a e. ( Atoms ` K ) /\ b e. ( Atoms ` K ) ) ) -> ( X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } -> ( X C_ ( Atoms ` K ) /\ A. p e. X A. q e. X A. r e. ( Atoms ` K ) ( r ( le ` K ) ( p ( join ` K ) q ) -> r e. X ) ) ) ) |
| 68 | 67 | adantld | |- ( ( K e. Lat /\ ( a e. ( Atoms ` K ) /\ b e. ( Atoms ` K ) ) ) -> ( ( a =/= b /\ X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } ) -> ( X C_ ( Atoms ` K ) /\ A. p e. X A. q e. X A. r e. ( Atoms ` K ) ( r ( le ` K ) ( p ( join ` K ) q ) -> r e. X ) ) ) ) |
| 69 | 68 | rexlimdvva | |- ( K e. Lat -> ( E. a e. ( Atoms ` K ) E. b e. ( Atoms ` K ) ( a =/= b /\ X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } ) -> ( X C_ ( Atoms ` K ) /\ A. p e. X A. q e. X A. r e. ( Atoms ` K ) ( r ( le ` K ) ( p ( join ` K ) q ) -> r e. X ) ) ) ) |
| 70 | 37 12 8 1 | isline | |- ( K e. Lat -> ( X e. N <-> E. a e. ( Atoms ` K ) E. b e. ( Atoms ` K ) ( a =/= b /\ X = { c e. ( Atoms ` K ) | c ( le ` K ) ( a ( join ` K ) b ) } ) ) ) |
| 71 | 37 12 8 2 | ispsubsp | |- ( K e. Lat -> ( X e. S <-> ( X C_ ( Atoms ` K ) /\ A. p e. X A. q e. X A. r e. ( Atoms ` K ) ( r ( le ` K ) ( p ( join ` K ) q ) -> r e. X ) ) ) ) |
| 72 | 69 70 71 | 3imtr4d | |- ( K e. Lat -> ( X e. N -> X e. S ) ) |
| 73 | 72 | imp | |- ( ( K e. Lat /\ X e. N ) -> X e. S ) |