| 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 ) ) ) ) ) ) )  |