| Step | Hyp | Ref | Expression | 
						
							| 1 |  | enrer |  |-  ~R Er ( P. X. P. ) | 
						
							| 2 | 1 | a1i |  |-  ( ( ( A e. ( ( P. X. P. ) /. ~R ) /\ B e. ( ( P. X. P. ) /. ~R ) ) /\ ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) ) ) -> ~R Er ( P. X. P. ) ) | 
						
							| 3 |  | prsrlem1 |  |-  ( ( ( A e. ( ( P. X. P. ) /. ~R ) /\ B e. ( ( P. X. P. ) /. ~R ) ) /\ ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) ) ) -> ( ( ( ( w e. P. /\ v e. P. ) /\ ( s e. P. /\ f e. P. ) ) /\ ( ( u e. P. /\ t e. P. ) /\ ( g e. P. /\ h e. P. ) ) ) /\ ( ( w +P. f ) = ( v +P. s ) /\ ( u +P. h ) = ( t +P. g ) ) ) ) | 
						
							| 4 |  | mulcmpblnr |  |-  ( ( ( ( w e. P. /\ v e. P. ) /\ ( s e. P. /\ f e. P. ) ) /\ ( ( u e. P. /\ t e. P. ) /\ ( g e. P. /\ h e. P. ) ) ) -> ( ( ( w +P. f ) = ( v +P. s ) /\ ( u +P. h ) = ( t +P. g ) ) -> <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ~R <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ) ) | 
						
							| 5 | 4 | imp |  |-  ( ( ( ( ( w e. P. /\ v e. P. ) /\ ( s e. P. /\ f e. P. ) ) /\ ( ( u e. P. /\ t e. P. ) /\ ( g e. P. /\ h e. P. ) ) ) /\ ( ( w +P. f ) = ( v +P. s ) /\ ( u +P. h ) = ( t +P. g ) ) ) -> <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ~R <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ) | 
						
							| 6 | 3 5 | syl |  |-  ( ( ( A e. ( ( P. X. P. ) /. ~R ) /\ B e. ( ( P. X. P. ) /. ~R ) ) /\ ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) ) ) -> <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ~R <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ) | 
						
							| 7 | 2 6 | erthi |  |-  ( ( ( A e. ( ( P. X. P. ) /. ~R ) /\ B e. ( ( P. X. P. ) /. ~R ) ) /\ ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) ) ) -> [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) | 
						
							| 8 | 7 | adantrlr |  |-  ( ( ( A e. ( ( P. X. P. ) /. ~R ) /\ B e. ( ( P. X. P. ) /. ~R ) ) /\ ( ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) /\ ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) ) ) -> [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) | 
						
							| 9 | 8 | adantrrr |  |-  ( ( ( A e. ( ( P. X. P. ) /. ~R ) /\ B e. ( ( P. X. P. ) /. ~R ) ) /\ ( ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) /\ ( ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) /\ q = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) ) ) -> [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) | 
						
							| 10 |  | simprlr |  |-  ( ( ( A e. ( ( P. X. P. ) /. ~R ) /\ B e. ( ( P. X. P. ) /. ~R ) ) /\ ( ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) /\ ( ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) /\ q = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) ) ) -> z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) | 
						
							| 11 |  | simprrr |  |-  ( ( ( A e. ( ( P. X. P. ) /. ~R ) /\ B e. ( ( P. X. P. ) /. ~R ) ) /\ ( ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) /\ ( ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) /\ q = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) ) ) -> q = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) | 
						
							| 12 | 9 10 11 | 3eqtr4d |  |-  ( ( ( A e. ( ( P. X. P. ) /. ~R ) /\ B e. ( ( P. X. P. ) /. ~R ) ) /\ ( ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) /\ ( ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) /\ q = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) ) ) -> z = q ) | 
						
							| 13 | 12 | expr |  |-  ( ( ( A e. ( ( P. X. P. ) /. ~R ) /\ B e. ( ( P. X. P. ) /. ~R ) ) /\ ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) ) -> ( ( ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) /\ q = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) -> z = q ) ) | 
						
							| 14 | 13 | exlimdvv |  |-  ( ( ( A e. ( ( P. X. P. ) /. ~R ) /\ B e. ( ( P. X. P. ) /. ~R ) ) /\ ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) ) -> ( E. g E. h ( ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) /\ q = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) -> z = q ) ) | 
						
							| 15 | 14 | exlimdvv |  |-  ( ( ( A e. ( ( P. X. P. ) /. ~R ) /\ B e. ( ( P. X. P. ) /. ~R ) ) /\ ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) ) -> ( E. s E. f E. g E. h ( ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) /\ q = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) -> z = q ) ) | 
						
							| 16 | 15 | ex |  |-  ( ( A e. ( ( P. X. P. ) /. ~R ) /\ B e. ( ( P. X. P. ) /. ~R ) ) -> ( ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) -> ( E. s E. f E. g E. h ( ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) /\ q = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) -> z = q ) ) ) | 
						
							| 17 | 16 | exlimdvv |  |-  ( ( A e. ( ( P. X. P. ) /. ~R ) /\ B e. ( ( P. X. P. ) /. ~R ) ) -> ( E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) -> ( E. s E. f E. g E. h ( ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) /\ q = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) -> z = q ) ) ) | 
						
							| 18 | 17 | exlimdvv |  |-  ( ( A e. ( ( P. X. P. ) /. ~R ) /\ B e. ( ( P. X. P. ) /. ~R ) ) -> ( E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) -> ( E. s E. f E. g E. h ( ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) /\ q = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) -> z = q ) ) ) | 
						
							| 19 | 18 | impd |  |-  ( ( A e. ( ( P. X. P. ) /. ~R ) /\ B e. ( ( P. X. P. ) /. ~R ) ) -> ( ( E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) /\ E. s E. f E. g E. h ( ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) /\ q = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) ) -> z = q ) ) | 
						
							| 20 | 19 | alrimivv |  |-  ( ( A e. ( ( P. X. P. ) /. ~R ) /\ B e. ( ( P. X. P. ) /. ~R ) ) -> A. z A. q ( ( E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) /\ E. s E. f E. g E. h ( ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) /\ q = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) ) -> z = q ) ) | 
						
							| 21 |  | opeq12 |  |-  ( ( w = s /\ v = f ) -> <. w , v >. = <. s , f >. ) | 
						
							| 22 | 21 | eceq1d |  |-  ( ( w = s /\ v = f ) -> [ <. w , v >. ] ~R = [ <. s , f >. ] ~R ) | 
						
							| 23 | 22 | eqeq2d |  |-  ( ( w = s /\ v = f ) -> ( A = [ <. w , v >. ] ~R <-> A = [ <. s , f >. ] ~R ) ) | 
						
							| 24 | 23 | anbi1d |  |-  ( ( w = s /\ v = f ) -> ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) <-> ( A = [ <. s , f >. ] ~R /\ B = [ <. u , t >. ] ~R ) ) ) | 
						
							| 25 |  | simpl |  |-  ( ( w = s /\ v = f ) -> w = s ) | 
						
							| 26 | 25 | oveq1d |  |-  ( ( w = s /\ v = f ) -> ( w .P. u ) = ( s .P. u ) ) | 
						
							| 27 |  | simpr |  |-  ( ( w = s /\ v = f ) -> v = f ) | 
						
							| 28 | 27 | oveq1d |  |-  ( ( w = s /\ v = f ) -> ( v .P. t ) = ( f .P. t ) ) | 
						
							| 29 | 26 28 | oveq12d |  |-  ( ( w = s /\ v = f ) -> ( ( w .P. u ) +P. ( v .P. t ) ) = ( ( s .P. u ) +P. ( f .P. t ) ) ) | 
						
							| 30 | 25 | oveq1d |  |-  ( ( w = s /\ v = f ) -> ( w .P. t ) = ( s .P. t ) ) | 
						
							| 31 | 27 | oveq1d |  |-  ( ( w = s /\ v = f ) -> ( v .P. u ) = ( f .P. u ) ) | 
						
							| 32 | 30 31 | oveq12d |  |-  ( ( w = s /\ v = f ) -> ( ( w .P. t ) +P. ( v .P. u ) ) = ( ( s .P. t ) +P. ( f .P. u ) ) ) | 
						
							| 33 | 29 32 | opeq12d |  |-  ( ( w = s /\ v = f ) -> <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. = <. ( ( s .P. u ) +P. ( f .P. t ) ) , ( ( s .P. t ) +P. ( f .P. u ) ) >. ) | 
						
							| 34 | 33 | eceq1d |  |-  ( ( w = s /\ v = f ) -> [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R = [ <. ( ( s .P. u ) +P. ( f .P. t ) ) , ( ( s .P. t ) +P. ( f .P. u ) ) >. ] ~R ) | 
						
							| 35 | 34 | eqeq2d |  |-  ( ( w = s /\ v = f ) -> ( q = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R <-> q = [ <. ( ( s .P. u ) +P. ( f .P. t ) ) , ( ( s .P. t ) +P. ( f .P. u ) ) >. ] ~R ) ) | 
						
							| 36 | 24 35 | anbi12d |  |-  ( ( w = s /\ v = f ) -> ( ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ q = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) <-> ( ( A = [ <. s , f >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ q = [ <. ( ( s .P. u ) +P. ( f .P. t ) ) , ( ( s .P. t ) +P. ( f .P. u ) ) >. ] ~R ) ) ) | 
						
							| 37 |  | opeq12 |  |-  ( ( u = g /\ t = h ) -> <. u , t >. = <. g , h >. ) | 
						
							| 38 | 37 | eceq1d |  |-  ( ( u = g /\ t = h ) -> [ <. u , t >. ] ~R = [ <. g , h >. ] ~R ) | 
						
							| 39 | 38 | eqeq2d |  |-  ( ( u = g /\ t = h ) -> ( B = [ <. u , t >. ] ~R <-> B = [ <. g , h >. ] ~R ) ) | 
						
							| 40 | 39 | anbi2d |  |-  ( ( u = g /\ t = h ) -> ( ( A = [ <. s , f >. ] ~R /\ B = [ <. u , t >. ] ~R ) <-> ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) ) ) | 
						
							| 41 |  | simpl |  |-  ( ( u = g /\ t = h ) -> u = g ) | 
						
							| 42 | 41 | oveq2d |  |-  ( ( u = g /\ t = h ) -> ( s .P. u ) = ( s .P. g ) ) | 
						
							| 43 |  | simpr |  |-  ( ( u = g /\ t = h ) -> t = h ) | 
						
							| 44 | 43 | oveq2d |  |-  ( ( u = g /\ t = h ) -> ( f .P. t ) = ( f .P. h ) ) | 
						
							| 45 | 42 44 | oveq12d |  |-  ( ( u = g /\ t = h ) -> ( ( s .P. u ) +P. ( f .P. t ) ) = ( ( s .P. g ) +P. ( f .P. h ) ) ) | 
						
							| 46 | 43 | oveq2d |  |-  ( ( u = g /\ t = h ) -> ( s .P. t ) = ( s .P. h ) ) | 
						
							| 47 | 41 | oveq2d |  |-  ( ( u = g /\ t = h ) -> ( f .P. u ) = ( f .P. g ) ) | 
						
							| 48 | 46 47 | oveq12d |  |-  ( ( u = g /\ t = h ) -> ( ( s .P. t ) +P. ( f .P. u ) ) = ( ( s .P. h ) +P. ( f .P. g ) ) ) | 
						
							| 49 | 45 48 | opeq12d |  |-  ( ( u = g /\ t = h ) -> <. ( ( s .P. u ) +P. ( f .P. t ) ) , ( ( s .P. t ) +P. ( f .P. u ) ) >. = <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ) | 
						
							| 50 | 49 | eceq1d |  |-  ( ( u = g /\ t = h ) -> [ <. ( ( s .P. u ) +P. ( f .P. t ) ) , ( ( s .P. t ) +P. ( f .P. u ) ) >. ] ~R = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) | 
						
							| 51 | 50 | eqeq2d |  |-  ( ( u = g /\ t = h ) -> ( q = [ <. ( ( s .P. u ) +P. ( f .P. t ) ) , ( ( s .P. t ) +P. ( f .P. u ) ) >. ] ~R <-> q = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) ) | 
						
							| 52 | 40 51 | anbi12d |  |-  ( ( u = g /\ t = h ) -> ( ( ( A = [ <. s , f >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ q = [ <. ( ( s .P. u ) +P. ( f .P. t ) ) , ( ( s .P. t ) +P. ( f .P. u ) ) >. ] ~R ) <-> ( ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) /\ q = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) ) ) | 
						
							| 53 | 36 52 | cbvex4vw |  |-  ( E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ q = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) <-> E. s E. f E. g E. h ( ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) /\ q = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) ) | 
						
							| 54 | 53 | anbi2i |  |-  ( ( E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) /\ E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ q = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) ) <-> ( E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) /\ E. s E. f E. g E. h ( ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) /\ q = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) ) ) | 
						
							| 55 | 54 | imbi1i |  |-  ( ( ( E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) /\ E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ q = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) ) -> z = q ) <-> ( ( E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) /\ E. s E. f E. g E. h ( ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) /\ q = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) ) -> z = q ) ) | 
						
							| 56 | 55 | 2albii |  |-  ( A. z A. q ( ( E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) /\ E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ q = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) ) -> z = q ) <-> A. z A. q ( ( E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) /\ E. s E. f E. g E. h ( ( A = [ <. s , f >. ] ~R /\ B = [ <. g , h >. ] ~R ) /\ q = [ <. ( ( s .P. g ) +P. ( f .P. h ) ) , ( ( s .P. h ) +P. ( f .P. g ) ) >. ] ~R ) ) -> z = q ) ) | 
						
							| 57 | 20 56 | sylibr |  |-  ( ( A e. ( ( P. X. P. ) /. ~R ) /\ B e. ( ( P. X. P. ) /. ~R ) ) -> A. z A. q ( ( E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) /\ E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ q = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) ) -> z = q ) ) | 
						
							| 58 |  | eqeq1 |  |-  ( z = q -> ( z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R <-> q = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) ) | 
						
							| 59 | 58 | anbi2d |  |-  ( z = q -> ( ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) <-> ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ q = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) ) ) | 
						
							| 60 | 59 | 4exbidv |  |-  ( z = q -> ( E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) <-> E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ q = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) ) ) | 
						
							| 61 | 60 | mo4 |  |-  ( E* z E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) <-> A. z A. q ( ( E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) /\ E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ q = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) ) -> z = q ) ) | 
						
							| 62 | 57 61 | sylibr |  |-  ( ( A e. ( ( P. X. P. ) /. ~R ) /\ B e. ( ( P. X. P. ) /. ~R ) ) -> E* z E. w E. v E. u E. t ( ( A = [ <. w , v >. ] ~R /\ B = [ <. u , t >. ] ~R ) /\ z = [ <. ( ( w .P. u ) +P. ( v .P. t ) ) , ( ( w .P. t ) +P. ( v .P. u ) ) >. ] ~R ) ) |