| Step | Hyp | Ref | Expression | 
						
							| 1 |  | itscnhlinecirc02plem2.d |  |-  D = ( X - A ) | 
						
							| 2 |  | itscnhlinecirc02plem2.e |  |-  E = ( B - Y ) | 
						
							| 3 |  | itscnhlinecirc02plem2.c |  |-  C = ( ( B x. X ) - ( A x. Y ) ) | 
						
							| 4 |  | simpl1l |  |-  ( ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) /\ B =/= Y ) /\ ( R e. RR /\ ( ( A ^ 2 ) + ( B ^ 2 ) ) < ( R ^ 2 ) ) ) -> A e. RR ) | 
						
							| 5 |  | simpl1r |  |-  ( ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) /\ B =/= Y ) /\ ( R e. RR /\ ( ( A ^ 2 ) + ( B ^ 2 ) ) < ( R ^ 2 ) ) ) -> B e. RR ) | 
						
							| 6 |  | simpl2l |  |-  ( ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) /\ B =/= Y ) /\ ( R e. RR /\ ( ( A ^ 2 ) + ( B ^ 2 ) ) < ( R ^ 2 ) ) ) -> X e. RR ) | 
						
							| 7 |  | simpl2r |  |-  ( ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) /\ B =/= Y ) /\ ( R e. RR /\ ( ( A ^ 2 ) + ( B ^ 2 ) ) < ( R ^ 2 ) ) ) -> Y e. RR ) | 
						
							| 8 |  | eqid |  |-  ( ( D x. B ) + ( E x. A ) ) = ( ( D x. B ) + ( E x. A ) ) | 
						
							| 9 |  | simprl |  |-  ( ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) /\ B =/= Y ) /\ ( R e. RR /\ ( ( A ^ 2 ) + ( B ^ 2 ) ) < ( R ^ 2 ) ) ) -> R e. RR ) | 
						
							| 10 |  | simprr |  |-  ( ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) /\ B =/= Y ) /\ ( R e. RR /\ ( ( A ^ 2 ) + ( B ^ 2 ) ) < ( R ^ 2 ) ) ) -> ( ( A ^ 2 ) + ( B ^ 2 ) ) < ( R ^ 2 ) ) | 
						
							| 11 |  | simpl3 |  |-  ( ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) /\ B =/= Y ) /\ ( R e. RR /\ ( ( A ^ 2 ) + ( B ^ 2 ) ) < ( R ^ 2 ) ) ) -> B =/= Y ) | 
						
							| 12 | 4 5 6 7 1 2 8 9 10 11 | itscnhlinecirc02plem1 |  |-  ( ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) /\ B =/= Y ) /\ ( R e. RR /\ ( ( A ^ 2 ) + ( B ^ 2 ) ) < ( R ^ 2 ) ) ) -> 0 < ( ( -u ( 2 x. ( D x. ( ( D x. B ) + ( E x. A ) ) ) ) ^ 2 ) - ( 4 x. ( ( ( E ^ 2 ) + ( D ^ 2 ) ) x. ( ( ( ( D x. B ) + ( E x. A ) ) ^ 2 ) - ( ( E ^ 2 ) x. ( R ^ 2 ) ) ) ) ) ) ) | 
						
							| 13 |  | simplr |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> B e. RR ) | 
						
							| 14 | 13 | recnd |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> B e. CC ) | 
						
							| 15 |  | simprl |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> X e. RR ) | 
						
							| 16 | 15 | recnd |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> X e. CC ) | 
						
							| 17 | 14 16 | mulcomd |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( B x. X ) = ( X x. B ) ) | 
						
							| 18 |  | simpll |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> A e. RR ) | 
						
							| 19 | 18 | recnd |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> A e. CC ) | 
						
							| 20 |  | simprr |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> Y e. RR ) | 
						
							| 21 | 20 | recnd |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> Y e. CC ) | 
						
							| 22 | 19 21 | mulcomd |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( A x. Y ) = ( Y x. A ) ) | 
						
							| 23 | 17 22 | oveq12d |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( ( B x. X ) - ( A x. Y ) ) = ( ( X x. B ) - ( Y x. A ) ) ) | 
						
							| 24 | 16 19 14 | subdird |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( ( X - A ) x. B ) = ( ( X x. B ) - ( A x. B ) ) ) | 
						
							| 25 | 14 21 19 | subdird |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( ( B - Y ) x. A ) = ( ( B x. A ) - ( Y x. A ) ) ) | 
						
							| 26 | 24 25 | oveq12d |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( ( ( X - A ) x. B ) + ( ( B - Y ) x. A ) ) = ( ( ( X x. B ) - ( A x. B ) ) + ( ( B x. A ) - ( Y x. A ) ) ) ) | 
						
							| 27 | 14 19 | mulcomd |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( B x. A ) = ( A x. B ) ) | 
						
							| 28 | 27 | oveq1d |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( ( B x. A ) - ( Y x. A ) ) = ( ( A x. B ) - ( Y x. A ) ) ) | 
						
							| 29 | 28 | oveq2d |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( ( ( X x. B ) - ( A x. B ) ) + ( ( B x. A ) - ( Y x. A ) ) ) = ( ( ( X x. B ) - ( A x. B ) ) + ( ( A x. B ) - ( Y x. A ) ) ) ) | 
						
							| 30 | 16 14 | mulcld |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( X x. B ) e. CC ) | 
						
							| 31 | 19 14 | mulcld |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( A x. B ) e. CC ) | 
						
							| 32 | 21 19 | mulcld |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( Y x. A ) e. CC ) | 
						
							| 33 | 30 31 32 | npncand |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( ( ( X x. B ) - ( A x. B ) ) + ( ( A x. B ) - ( Y x. A ) ) ) = ( ( X x. B ) - ( Y x. A ) ) ) | 
						
							| 34 | 26 29 33 | 3eqtrd |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( ( ( X - A ) x. B ) + ( ( B - Y ) x. A ) ) = ( ( X x. B ) - ( Y x. A ) ) ) | 
						
							| 35 | 23 34 | eqtr4d |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( ( B x. X ) - ( A x. Y ) ) = ( ( ( X - A ) x. B ) + ( ( B - Y ) x. A ) ) ) | 
						
							| 36 | 1 | oveq1i |  |-  ( D x. B ) = ( ( X - A ) x. B ) | 
						
							| 37 | 2 | oveq1i |  |-  ( E x. A ) = ( ( B - Y ) x. A ) | 
						
							| 38 | 36 37 | oveq12i |  |-  ( ( D x. B ) + ( E x. A ) ) = ( ( ( X - A ) x. B ) + ( ( B - Y ) x. A ) ) | 
						
							| 39 | 35 3 38 | 3eqtr4g |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> C = ( ( D x. B ) + ( E x. A ) ) ) | 
						
							| 40 | 39 | oveq2d |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( D x. C ) = ( D x. ( ( D x. B ) + ( E x. A ) ) ) ) | 
						
							| 41 | 40 | oveq2d |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( 2 x. ( D x. C ) ) = ( 2 x. ( D x. ( ( D x. B ) + ( E x. A ) ) ) ) ) | 
						
							| 42 | 41 | negeqd |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> -u ( 2 x. ( D x. C ) ) = -u ( 2 x. ( D x. ( ( D x. B ) + ( E x. A ) ) ) ) ) | 
						
							| 43 | 42 | oveq1d |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( -u ( 2 x. ( D x. C ) ) ^ 2 ) = ( -u ( 2 x. ( D x. ( ( D x. B ) + ( E x. A ) ) ) ) ^ 2 ) ) | 
						
							| 44 | 39 | oveq1d |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( C ^ 2 ) = ( ( ( D x. B ) + ( E x. A ) ) ^ 2 ) ) | 
						
							| 45 | 44 | oveq1d |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( ( C ^ 2 ) - ( ( E ^ 2 ) x. ( R ^ 2 ) ) ) = ( ( ( ( D x. B ) + ( E x. A ) ) ^ 2 ) - ( ( E ^ 2 ) x. ( R ^ 2 ) ) ) ) | 
						
							| 46 | 45 | oveq2d |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( ( ( E ^ 2 ) + ( D ^ 2 ) ) x. ( ( C ^ 2 ) - ( ( E ^ 2 ) x. ( R ^ 2 ) ) ) ) = ( ( ( E ^ 2 ) + ( D ^ 2 ) ) x. ( ( ( ( D x. B ) + ( E x. A ) ) ^ 2 ) - ( ( E ^ 2 ) x. ( R ^ 2 ) ) ) ) ) | 
						
							| 47 | 46 | oveq2d |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( 4 x. ( ( ( E ^ 2 ) + ( D ^ 2 ) ) x. ( ( C ^ 2 ) - ( ( E ^ 2 ) x. ( R ^ 2 ) ) ) ) ) = ( 4 x. ( ( ( E ^ 2 ) + ( D ^ 2 ) ) x. ( ( ( ( D x. B ) + ( E x. A ) ) ^ 2 ) - ( ( E ^ 2 ) x. ( R ^ 2 ) ) ) ) ) ) | 
						
							| 48 | 43 47 | oveq12d |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) ) -> ( ( -u ( 2 x. ( D x. C ) ) ^ 2 ) - ( 4 x. ( ( ( E ^ 2 ) + ( D ^ 2 ) ) x. ( ( C ^ 2 ) - ( ( E ^ 2 ) x. ( R ^ 2 ) ) ) ) ) ) = ( ( -u ( 2 x. ( D x. ( ( D x. B ) + ( E x. A ) ) ) ) ^ 2 ) - ( 4 x. ( ( ( E ^ 2 ) + ( D ^ 2 ) ) x. ( ( ( ( D x. B ) + ( E x. A ) ) ^ 2 ) - ( ( E ^ 2 ) x. ( R ^ 2 ) ) ) ) ) ) ) | 
						
							| 49 | 48 | 3adant3 |  |-  ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) /\ B =/= Y ) -> ( ( -u ( 2 x. ( D x. C ) ) ^ 2 ) - ( 4 x. ( ( ( E ^ 2 ) + ( D ^ 2 ) ) x. ( ( C ^ 2 ) - ( ( E ^ 2 ) x. ( R ^ 2 ) ) ) ) ) ) = ( ( -u ( 2 x. ( D x. ( ( D x. B ) + ( E x. A ) ) ) ) ^ 2 ) - ( 4 x. ( ( ( E ^ 2 ) + ( D ^ 2 ) ) x. ( ( ( ( D x. B ) + ( E x. A ) ) ^ 2 ) - ( ( E ^ 2 ) x. ( R ^ 2 ) ) ) ) ) ) ) | 
						
							| 50 | 49 | adantr |  |-  ( ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) /\ B =/= Y ) /\ ( R e. RR /\ ( ( A ^ 2 ) + ( B ^ 2 ) ) < ( R ^ 2 ) ) ) -> ( ( -u ( 2 x. ( D x. C ) ) ^ 2 ) - ( 4 x. ( ( ( E ^ 2 ) + ( D ^ 2 ) ) x. ( ( C ^ 2 ) - ( ( E ^ 2 ) x. ( R ^ 2 ) ) ) ) ) ) = ( ( -u ( 2 x. ( D x. ( ( D x. B ) + ( E x. A ) ) ) ) ^ 2 ) - ( 4 x. ( ( ( E ^ 2 ) + ( D ^ 2 ) ) x. ( ( ( ( D x. B ) + ( E x. A ) ) ^ 2 ) - ( ( E ^ 2 ) x. ( R ^ 2 ) ) ) ) ) ) ) | 
						
							| 51 | 12 50 | breqtrrd |  |-  ( ( ( ( A e. RR /\ B e. RR ) /\ ( X e. RR /\ Y e. RR ) /\ B =/= Y ) /\ ( R e. RR /\ ( ( A ^ 2 ) + ( B ^ 2 ) ) < ( R ^ 2 ) ) ) -> 0 < ( ( -u ( 2 x. ( D x. C ) ) ^ 2 ) - ( 4 x. ( ( ( E ^ 2 ) + ( D ^ 2 ) ) x. ( ( C ^ 2 ) - ( ( E ^ 2 ) x. ( R ^ 2 ) ) ) ) ) ) ) |