| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							cdlemef44.b | 
							 |-  B = ( Base ` K )  | 
						
						
							| 2 | 
							
								
							 | 
							cdlemef44.l | 
							 |-  .<_ = ( le ` K )  | 
						
						
							| 3 | 
							
								
							 | 
							cdlemef44.j | 
							 |-  .\/ = ( join ` K )  | 
						
						
							| 4 | 
							
								
							 | 
							cdlemef44.m | 
							 |-  ./\ = ( meet ` K )  | 
						
						
							| 5 | 
							
								
							 | 
							cdlemef44.a | 
							 |-  A = ( Atoms ` K )  | 
						
						
							| 6 | 
							
								
							 | 
							cdlemef44.h | 
							 |-  H = ( LHyp ` K )  | 
						
						
							| 7 | 
							
								
							 | 
							cdlemef44.u | 
							 |-  U = ( ( P .\/ Q ) ./\ W )  | 
						
						
							| 8 | 
							
								
							 | 
							cdlemef44.d | 
							 |-  D = ( ( t .\/ U ) ./\ ( Q .\/ ( ( P .\/ t ) ./\ W ) ) )  | 
						
						
							| 9 | 
							
								
							 | 
							cdlemef44.o | 
							 |-  O = ( iota_ z e. B A. s e. A ( ( -. s .<_ W /\ ( s .\/ ( x ./\ W ) ) = x ) -> z = ( if ( s .<_ ( P .\/ Q ) , I , [_ s / t ]_ D ) .\/ ( x ./\ W ) ) ) )  | 
						
						
							| 10 | 
							
								
							 | 
							cdlemef44.f | 
							 |-  F = ( x e. B |-> if ( ( P =/= Q /\ -. x .<_ W ) , O , x ) )  | 
						
						
							| 11 | 
							
								
							 | 
							cdlemefs44.e | 
							 |-  E = ( ( P .\/ Q ) ./\ ( D .\/ ( ( s .\/ t ) ./\ W ) ) )  | 
						
						
							| 12 | 
							
								
							 | 
							cdlemefs44.i | 
							 |-  I = ( iota_ y e. B A. t e. A ( ( -. t .<_ W /\ -. t .<_ ( P .\/ Q ) ) -> y = E ) )  | 
						
						
							| 13 | 
							
								
							 | 
							eqid | 
							 |-  if ( s .<_ ( P .\/ Q ) , I , [_ s / t ]_ D ) = if ( s .<_ ( P .\/ Q ) , I , [_ s / t ]_ D )  | 
						
						
							| 14 | 
							
								
							 | 
							eqid | 
							 |-  ( ( S .\/ U ) ./\ ( Q .\/ ( ( P .\/ S ) ./\ W ) ) ) = ( ( S .\/ U ) ./\ ( Q .\/ ( ( P .\/ S ) ./\ W ) ) )  | 
						
						
							| 15 | 
							
								
							 | 
							eqid | 
							 |-  ( ( P .\/ Q ) ./\ ( ( ( S .\/ U ) ./\ ( Q .\/ ( ( P .\/ S ) ./\ W ) ) ) .\/ ( ( R .\/ S ) ./\ W ) ) ) = ( ( P .\/ Q ) ./\ ( ( ( S .\/ U ) ./\ ( Q .\/ ( ( P .\/ S ) ./\ W ) ) ) .\/ ( ( R .\/ S ) ./\ W ) ) )  | 
						
						
							| 16 | 
							
								1 2 3 4 5 6 7 8 11 12 13 9 10 14 15
							 | 
							cdlemefs31fv1 | 
							 |-  ( ( ( ( K e. HL /\ W e. H ) /\ ( P e. A /\ -. P .<_ W ) /\ ( Q e. A /\ -. Q .<_ W ) ) /\ ( P =/= Q /\ ( R e. A /\ -. R .<_ W ) /\ ( S e. A /\ -. S .<_ W ) ) /\ ( R .<_ ( P .\/ Q ) /\ -. S .<_ ( P .\/ Q ) ) ) -> ( F ` R ) = ( ( P .\/ Q ) ./\ ( ( ( S .\/ U ) ./\ ( Q .\/ ( ( P .\/ S ) ./\ W ) ) ) .\/ ( ( R .\/ S ) ./\ W ) ) ) )  | 
						
						
							| 17 | 
							
								
							 | 
							simp22l | 
							 |-  ( ( ( ( K e. HL /\ W e. H ) /\ ( P e. A /\ -. P .<_ W ) /\ ( Q e. A /\ -. Q .<_ W ) ) /\ ( P =/= Q /\ ( R e. A /\ -. R .<_ W ) /\ ( S e. A /\ -. S .<_ W ) ) /\ ( R .<_ ( P .\/ Q ) /\ -. S .<_ ( P .\/ Q ) ) ) -> R e. A )  | 
						
						
							| 18 | 
							
								
							 | 
							simp23l | 
							 |-  ( ( ( ( K e. HL /\ W e. H ) /\ ( P e. A /\ -. P .<_ W ) /\ ( Q e. A /\ -. Q .<_ W ) ) /\ ( P =/= Q /\ ( R e. A /\ -. R .<_ W ) /\ ( S e. A /\ -. S .<_ W ) ) /\ ( R .<_ ( P .\/ Q ) /\ -. S .<_ ( P .\/ Q ) ) ) -> S e. A )  | 
						
						
							| 19 | 
							
								8 11 14 15
							 | 
							cdleme31sde | 
							 |-  ( ( R e. A /\ S e. A ) -> [_ R / s ]_ [_ S / t ]_ E = ( ( P .\/ Q ) ./\ ( ( ( S .\/ U ) ./\ ( Q .\/ ( ( P .\/ S ) ./\ W ) ) ) .\/ ( ( R .\/ S ) ./\ W ) ) ) )  | 
						
						
							| 20 | 
							
								17 18 19
							 | 
							syl2anc | 
							 |-  ( ( ( ( K e. HL /\ W e. H ) /\ ( P e. A /\ -. P .<_ W ) /\ ( Q e. A /\ -. Q .<_ W ) ) /\ ( P =/= Q /\ ( R e. A /\ -. R .<_ W ) /\ ( S e. A /\ -. S .<_ W ) ) /\ ( R .<_ ( P .\/ Q ) /\ -. S .<_ ( P .\/ Q ) ) ) -> [_ R / s ]_ [_ S / t ]_ E = ( ( P .\/ Q ) ./\ ( ( ( S .\/ U ) ./\ ( Q .\/ ( ( P .\/ S ) ./\ W ) ) ) .\/ ( ( R .\/ S ) ./\ W ) ) ) )  | 
						
						
							| 21 | 
							
								16 20
							 | 
							eqtr4d | 
							 |-  ( ( ( ( K e. HL /\ W e. H ) /\ ( P e. A /\ -. P .<_ W ) /\ ( Q e. A /\ -. Q .<_ W ) ) /\ ( P =/= Q /\ ( R e. A /\ -. R .<_ W ) /\ ( S e. A /\ -. S .<_ W ) ) /\ ( R .<_ ( P .\/ Q ) /\ -. S .<_ ( P .\/ Q ) ) ) -> ( F ` R ) = [_ R / s ]_ [_ S / t ]_ E )  |