| Step | Hyp | Ref | Expression | 
						
							| 1 |  | atcvrlln2.l |  |-  .<_ = ( le ` K ) | 
						
							| 2 |  | atcvrlln2.c |  |-  C = (  | 
						
							| 3 |  | atcvrlln2.a |  |-  A = ( Atoms ` K ) | 
						
							| 4 |  | atcvrlln2.n |  |-  N = ( LLines ` K ) | 
						
							| 5 |  | simpl3 |  |-  ( ( ( K e. HL /\ P e. A /\ X e. N ) /\ P .<_ X ) -> X e. N ) | 
						
							| 6 |  | simpl1 |  |-  ( ( ( K e. HL /\ P e. A /\ X e. N ) /\ P .<_ X ) -> K e. HL ) | 
						
							| 7 |  | eqid |  |-  ( Base ` K ) = ( Base ` K ) | 
						
							| 8 | 7 4 | llnbase |  |-  ( X e. N -> X e. ( Base ` K ) ) | 
						
							| 9 | 5 8 | syl |  |-  ( ( ( K e. HL /\ P e. A /\ X e. N ) /\ P .<_ X ) -> X e. ( Base ` K ) ) | 
						
							| 10 |  | eqid |  |-  ( join ` K ) = ( join ` K ) | 
						
							| 11 | 7 10 3 4 | islln3 |  |-  ( ( K e. HL /\ X e. ( Base ` K ) ) -> ( X e. N <-> E. q e. A E. r e. A ( q =/= r /\ X = ( q ( join ` K ) r ) ) ) ) | 
						
							| 12 | 6 9 11 | syl2anc |  |-  ( ( ( K e. HL /\ P e. A /\ X e. N ) /\ P .<_ X ) -> ( X e. N <-> E. q e. A E. r e. A ( q =/= r /\ X = ( q ( join ` K ) r ) ) ) ) | 
						
							| 13 | 5 12 | mpbid |  |-  ( ( ( K e. HL /\ P e. A /\ X e. N ) /\ P .<_ X ) -> E. q e. A E. r e. A ( q =/= r /\ X = ( q ( join ` K ) r ) ) ) | 
						
							| 14 |  | simp1l1 |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. N ) /\ P .<_ X ) /\ ( q e. A /\ r e. A ) /\ ( q =/= r /\ X = ( q ( join ` K ) r ) ) ) -> K e. HL ) | 
						
							| 15 |  | simp1l2 |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. N ) /\ P .<_ X ) /\ ( q e. A /\ r e. A ) /\ ( q =/= r /\ X = ( q ( join ` K ) r ) ) ) -> P e. A ) | 
						
							| 16 |  | simp2l |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. N ) /\ P .<_ X ) /\ ( q e. A /\ r e. A ) /\ ( q =/= r /\ X = ( q ( join ` K ) r ) ) ) -> q e. A ) | 
						
							| 17 |  | simp2r |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. N ) /\ P .<_ X ) /\ ( q e. A /\ r e. A ) /\ ( q =/= r /\ X = ( q ( join ` K ) r ) ) ) -> r e. A ) | 
						
							| 18 |  | simp3l |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. N ) /\ P .<_ X ) /\ ( q e. A /\ r e. A ) /\ ( q =/= r /\ X = ( q ( join ` K ) r ) ) ) -> q =/= r ) | 
						
							| 19 |  | simp1r |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. N ) /\ P .<_ X ) /\ ( q e. A /\ r e. A ) /\ ( q =/= r /\ X = ( q ( join ` K ) r ) ) ) -> P .<_ X ) | 
						
							| 20 |  | simp3r |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. N ) /\ P .<_ X ) /\ ( q e. A /\ r e. A ) /\ ( q =/= r /\ X = ( q ( join ` K ) r ) ) ) -> X = ( q ( join ` K ) r ) ) | 
						
							| 21 | 19 20 | breqtrd |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. N ) /\ P .<_ X ) /\ ( q e. A /\ r e. A ) /\ ( q =/= r /\ X = ( q ( join ` K ) r ) ) ) -> P .<_ ( q ( join ` K ) r ) ) | 
						
							| 22 | 1 10 2 3 | atcvrj2 |  |-  ( ( K e. HL /\ ( P e. A /\ q e. A /\ r e. A ) /\ ( q =/= r /\ P .<_ ( q ( join ` K ) r ) ) ) -> P C ( q ( join ` K ) r ) ) | 
						
							| 23 | 14 15 16 17 18 21 22 | syl132anc |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. N ) /\ P .<_ X ) /\ ( q e. A /\ r e. A ) /\ ( q =/= r /\ X = ( q ( join ` K ) r ) ) ) -> P C ( q ( join ` K ) r ) ) | 
						
							| 24 | 23 20 | breqtrrd |  |-  ( ( ( ( K e. HL /\ P e. A /\ X e. N ) /\ P .<_ X ) /\ ( q e. A /\ r e. A ) /\ ( q =/= r /\ X = ( q ( join ` K ) r ) ) ) -> P C X ) | 
						
							| 25 | 24 | 3exp |  |-  ( ( ( K e. HL /\ P e. A /\ X e. N ) /\ P .<_ X ) -> ( ( q e. A /\ r e. A ) -> ( ( q =/= r /\ X = ( q ( join ` K ) r ) ) -> P C X ) ) ) | 
						
							| 26 | 25 | rexlimdvv |  |-  ( ( ( K e. HL /\ P e. A /\ X e. N ) /\ P .<_ X ) -> ( E. q e. A E. r e. A ( q =/= r /\ X = ( q ( join ` K ) r ) ) -> P C X ) ) | 
						
							| 27 | 13 26 | mpd |  |-  ( ( ( K e. HL /\ P e. A /\ X e. N ) /\ P .<_ X ) -> P C X ) |