| Step | Hyp | Ref | Expression | 
						
							| 1 |  | lvolex3.l |  |-  .<_ = ( le ` K ) | 
						
							| 2 |  | lvolex3.a |  |-  A = ( Atoms ` K ) | 
						
							| 3 |  | lvolex3.p |  |-  P = ( LPlanes ` K ) | 
						
							| 4 |  | eqid |  |-  ( Base ` K ) = ( Base ` K ) | 
						
							| 5 |  | eqid |  |-  ( join ` K ) = ( join ` K ) | 
						
							| 6 | 4 1 5 2 3 | islpln2 |  |-  ( K e. HL -> ( X e. P <-> ( X e. ( Base ` K ) /\ E. r e. A E. s e. A E. t e. A ( r =/= s /\ -. t .<_ ( r ( join ` K ) s ) /\ X = ( ( r ( join ` K ) s ) ( join ` K ) t ) ) ) ) ) | 
						
							| 7 |  | simp1l |  |-  ( ( ( K e. HL /\ ( r e. A /\ s e. A ) ) /\ t e. A /\ ( r =/= s /\ -. t .<_ ( r ( join ` K ) s ) /\ X = ( ( r ( join ` K ) s ) ( join ` K ) t ) ) ) -> K e. HL ) | 
						
							| 8 |  | simp1rl |  |-  ( ( ( K e. HL /\ ( r e. A /\ s e. A ) ) /\ t e. A /\ ( r =/= s /\ -. t .<_ ( r ( join ` K ) s ) /\ X = ( ( r ( join ` K ) s ) ( join ` K ) t ) ) ) -> r e. A ) | 
						
							| 9 |  | simp1rr |  |-  ( ( ( K e. HL /\ ( r e. A /\ s e. A ) ) /\ t e. A /\ ( r =/= s /\ -. t .<_ ( r ( join ` K ) s ) /\ X = ( ( r ( join ` K ) s ) ( join ` K ) t ) ) ) -> s e. A ) | 
						
							| 10 |  | simp2 |  |-  ( ( ( K e. HL /\ ( r e. A /\ s e. A ) ) /\ t e. A /\ ( r =/= s /\ -. t .<_ ( r ( join ` K ) s ) /\ X = ( ( r ( join ` K ) s ) ( join ` K ) t ) ) ) -> t e. A ) | 
						
							| 11 | 5 1 2 | 3dim3 |  |-  ( ( K e. HL /\ ( r e. A /\ s e. A /\ t e. A ) ) -> E. q e. A -. q .<_ ( ( r ( join ` K ) s ) ( join ` K ) t ) ) | 
						
							| 12 | 7 8 9 10 11 | syl13anc |  |-  ( ( ( K e. HL /\ ( r e. A /\ s e. A ) ) /\ t e. A /\ ( r =/= s /\ -. t .<_ ( r ( join ` K ) s ) /\ X = ( ( r ( join ` K ) s ) ( join ` K ) t ) ) ) -> E. q e. A -. q .<_ ( ( r ( join ` K ) s ) ( join ` K ) t ) ) | 
						
							| 13 |  | simp33 |  |-  ( ( ( K e. HL /\ ( r e. A /\ s e. A ) ) /\ t e. A /\ ( r =/= s /\ -. t .<_ ( r ( join ` K ) s ) /\ X = ( ( r ( join ` K ) s ) ( join ` K ) t ) ) ) -> X = ( ( r ( join ` K ) s ) ( join ` K ) t ) ) | 
						
							| 14 |  | breq2 |  |-  ( X = ( ( r ( join ` K ) s ) ( join ` K ) t ) -> ( q .<_ X <-> q .<_ ( ( r ( join ` K ) s ) ( join ` K ) t ) ) ) | 
						
							| 15 | 14 | notbid |  |-  ( X = ( ( r ( join ` K ) s ) ( join ` K ) t ) -> ( -. q .<_ X <-> -. q .<_ ( ( r ( join ` K ) s ) ( join ` K ) t ) ) ) | 
						
							| 16 | 15 | rexbidv |  |-  ( X = ( ( r ( join ` K ) s ) ( join ` K ) t ) -> ( E. q e. A -. q .<_ X <-> E. q e. A -. q .<_ ( ( r ( join ` K ) s ) ( join ` K ) t ) ) ) | 
						
							| 17 | 13 16 | syl |  |-  ( ( ( K e. HL /\ ( r e. A /\ s e. A ) ) /\ t e. A /\ ( r =/= s /\ -. t .<_ ( r ( join ` K ) s ) /\ X = ( ( r ( join ` K ) s ) ( join ` K ) t ) ) ) -> ( E. q e. A -. q .<_ X <-> E. q e. A -. q .<_ ( ( r ( join ` K ) s ) ( join ` K ) t ) ) ) | 
						
							| 18 | 12 17 | mpbird |  |-  ( ( ( K e. HL /\ ( r e. A /\ s e. A ) ) /\ t e. A /\ ( r =/= s /\ -. t .<_ ( r ( join ` K ) s ) /\ X = ( ( r ( join ` K ) s ) ( join ` K ) t ) ) ) -> E. q e. A -. q .<_ X ) | 
						
							| 19 | 18 | rexlimdv3a |  |-  ( ( K e. HL /\ ( r e. A /\ s e. A ) ) -> ( E. t e. A ( r =/= s /\ -. t .<_ ( r ( join ` K ) s ) /\ X = ( ( r ( join ` K ) s ) ( join ` K ) t ) ) -> E. q e. A -. q .<_ X ) ) | 
						
							| 20 | 19 | rexlimdvva |  |-  ( K e. HL -> ( E. r e. A E. s e. A E. t e. A ( r =/= s /\ -. t .<_ ( r ( join ` K ) s ) /\ X = ( ( r ( join ` K ) s ) ( join ` K ) t ) ) -> E. q e. A -. q .<_ X ) ) | 
						
							| 21 | 20 | adantld |  |-  ( K e. HL -> ( ( X e. ( Base ` K ) /\ E. r e. A E. s e. A E. t e. A ( r =/= s /\ -. t .<_ ( r ( join ` K ) s ) /\ X = ( ( r ( join ` K ) s ) ( join ` K ) t ) ) ) -> E. q e. A -. q .<_ X ) ) | 
						
							| 22 | 6 21 | sylbid |  |-  ( K e. HL -> ( X e. P -> E. q e. A -. q .<_ X ) ) | 
						
							| 23 | 22 | imp |  |-  ( ( K e. HL /\ X e. P ) -> E. q e. A -. q .<_ X ) |