| Step | Hyp | Ref | Expression | 
						
							| 1 |  | 2atomslt.b |  |-  B = ( Base ` K ) | 
						
							| 2 |  | 2atomslt.s |  |-  .< = ( lt ` K ) | 
						
							| 3 |  | 2atomslt.a |  |-  A = ( Atoms ` K ) | 
						
							| 4 | 1 3 | atbase |  |-  ( P e. A -> P e. B ) | 
						
							| 5 |  | eqid |  |-  ( le ` K ) = ( le ` K ) | 
						
							| 6 |  | eqid |  |-  ( join ` K ) = ( join ` K ) | 
						
							| 7 | 1 5 2 6 3 | hlrelat |  |-  ( ( ( K e. HL /\ P e. B /\ X e. B ) /\ P .< X ) -> E. q e. A ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) | 
						
							| 8 | 4 7 | syl3anl2 |  |-  ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) -> E. q e. A ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) | 
						
							| 9 |  | simp3l |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> P .< ( P ( join ` K ) q ) ) | 
						
							| 10 |  | simp1l1 |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> K e. HL ) | 
						
							| 11 |  | simp1l2 |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> P e. A ) | 
						
							| 12 |  | simp2 |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> q e. A ) | 
						
							| 13 |  | eqid |  |-  (  | 
						
							| 14 | 2 6 3 13 | atltcvr |  |-  ( ( K e. HL /\ ( P e. A /\ P e. A /\ q e. A ) ) -> ( P .< ( P ( join ` K ) q ) <-> P (  | 
						
							| 15 | 10 11 11 12 14 | syl13anc |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> ( P .< ( P ( join ` K ) q ) <-> P (  | 
						
							| 16 | 9 15 | mpbid |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> P (  | 
						
							| 17 | 6 13 3 | atcvr1 |  |-  ( ( K e. HL /\ P e. A /\ q e. A ) -> ( P =/= q <-> P (  | 
						
							| 18 | 10 11 12 17 | syl3anc |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> ( P =/= q <-> P (  | 
						
							| 19 | 16 18 | mpbird |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> P =/= q ) | 
						
							| 20 | 19 | necomd |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> q =/= P ) | 
						
							| 21 | 2 6 3 | atlt |  |-  ( ( K e. HL /\ q e. A /\ P e. A ) -> ( q .< ( q ( join ` K ) P ) <-> q =/= P ) ) | 
						
							| 22 | 10 12 11 21 | syl3anc |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> ( q .< ( q ( join ` K ) P ) <-> q =/= P ) ) | 
						
							| 23 | 20 22 | mpbird |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> q .< ( q ( join ` K ) P ) ) | 
						
							| 24 | 10 | hllatd |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> K e. Lat ) | 
						
							| 25 | 11 4 | syl |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> P e. B ) | 
						
							| 26 | 1 3 | atbase |  |-  ( q e. A -> q e. B ) | 
						
							| 27 | 26 | 3ad2ant2 |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> q e. B ) | 
						
							| 28 | 1 6 | latjcom |  |-  ( ( K e. Lat /\ P e. B /\ q e. B ) -> ( P ( join ` K ) q ) = ( q ( join ` K ) P ) ) | 
						
							| 29 | 24 25 27 28 | syl3anc |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> ( P ( join ` K ) q ) = ( q ( join ` K ) P ) ) | 
						
							| 30 | 23 29 | breqtrrd |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> q .< ( P ( join ` K ) q ) ) | 
						
							| 31 |  | simp3r |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> ( P ( join ` K ) q ) ( le ` K ) X ) | 
						
							| 32 |  | hlpos |  |-  ( K e. HL -> K e. Poset ) | 
						
							| 33 | 10 32 | syl |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> K e. Poset ) | 
						
							| 34 | 1 6 | latjcl |  |-  ( ( K e. Lat /\ P e. B /\ q e. B ) -> ( P ( join ` K ) q ) e. B ) | 
						
							| 35 | 24 25 27 34 | syl3anc |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> ( P ( join ` K ) q ) e. B ) | 
						
							| 36 |  | simp1l3 |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> X e. B ) | 
						
							| 37 | 1 5 2 | pltletr |  |-  ( ( K e. Poset /\ ( q e. B /\ ( P ( join ` K ) q ) e. B /\ X e. B ) ) -> ( ( q .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) -> q .< X ) ) | 
						
							| 38 | 33 27 35 36 37 | syl13anc |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> ( ( q .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) -> q .< X ) ) | 
						
							| 39 | 30 31 38 | mp2and |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> q .< X ) | 
						
							| 40 | 20 39 | jca |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) /\ q e. A /\ ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) ) -> ( q =/= P /\ q .< X ) ) | 
						
							| 41 | 40 | 3exp |  |-  ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) -> ( q e. A -> ( ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) -> ( q =/= P /\ q .< X ) ) ) ) | 
						
							| 42 | 41 | reximdvai |  |-  ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) -> ( E. q e. A ( P .< ( P ( join ` K ) q ) /\ ( P ( join ` K ) q ) ( le ` K ) X ) -> E. q e. A ( q =/= P /\ q .< X ) ) ) | 
						
							| 43 | 8 42 | mpd |  |-  ( ( ( K e. HL /\ P e. A /\ X e. B ) /\ P .< X ) -> E. q e. A ( q =/= P /\ q .< X ) ) |