| Step | Hyp | Ref | Expression | 
						
							| 1 |  | itscnhlinecirc02p.i |  |-  I = { 1 , 2 } | 
						
							| 2 |  | itscnhlinecirc02p.e |  |-  E = ( RR^ ` I ) | 
						
							| 3 |  | itscnhlinecirc02p.p |  |-  P = ( RR ^m I ) | 
						
							| 4 |  | itscnhlinecirc02p.s |  |-  S = ( Sphere ` E ) | 
						
							| 5 |  | itscnhlinecirc02p.0 |  |-  .0. = ( I X. { 0 } ) | 
						
							| 6 |  | itscnhlinecirc02p.l |  |-  L = ( LineM ` E ) | 
						
							| 7 |  | itscnhlinecirc02p.d |  |-  D = ( dist ` E ) | 
						
							| 8 | 1 3 | rrx2pxel |  |-  ( X e. P -> ( X ` 1 ) e. RR ) | 
						
							| 9 | 1 3 | rrx2pyel |  |-  ( X e. P -> ( X ` 2 ) e. RR ) | 
						
							| 10 | 8 9 | jca |  |-  ( X e. P -> ( ( X ` 1 ) e. RR /\ ( X ` 2 ) e. RR ) ) | 
						
							| 11 | 10 | 3ad2ant1 |  |-  ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) -> ( ( X ` 1 ) e. RR /\ ( X ` 2 ) e. RR ) ) | 
						
							| 12 | 11 | adantr |  |-  ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ ( R e. RR+ /\ ( X D .0. ) < R ) ) -> ( ( X ` 1 ) e. RR /\ ( X ` 2 ) e. RR ) ) | 
						
							| 13 | 1 3 | rrx2pxel |  |-  ( Y e. P -> ( Y ` 1 ) e. RR ) | 
						
							| 14 | 1 3 | rrx2pyel |  |-  ( Y e. P -> ( Y ` 2 ) e. RR ) | 
						
							| 15 | 13 14 | jca |  |-  ( Y e. P -> ( ( Y ` 1 ) e. RR /\ ( Y ` 2 ) e. RR ) ) | 
						
							| 16 | 15 | 3ad2ant2 |  |-  ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) -> ( ( Y ` 1 ) e. RR /\ ( Y ` 2 ) e. RR ) ) | 
						
							| 17 | 16 | adantr |  |-  ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ ( R e. RR+ /\ ( X D .0. ) < R ) ) -> ( ( Y ` 1 ) e. RR /\ ( Y ` 2 ) e. RR ) ) | 
						
							| 18 |  | simpl3 |  |-  ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ ( R e. RR+ /\ ( X D .0. ) < R ) ) -> ( X ` 2 ) =/= ( Y ` 2 ) ) | 
						
							| 19 |  | rpre |  |-  ( R e. RR+ -> R e. RR ) | 
						
							| 20 | 19 | adantr |  |-  ( ( R e. RR+ /\ ( X D .0. ) < R ) -> R e. RR ) | 
						
							| 21 | 20 | adantl |  |-  ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ ( R e. RR+ /\ ( X D .0. ) < R ) ) -> R e. RR ) | 
						
							| 22 |  | simpl1 |  |-  ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) -> X e. P ) | 
						
							| 23 |  | 2nn0 |  |-  2 e. NN0 | 
						
							| 24 |  | eqid |  |-  ( EEhil ` 2 ) = ( EEhil ` 2 ) | 
						
							| 25 | 24 | ehlval |  |-  ( 2 e. NN0 -> ( EEhil ` 2 ) = ( RR^ ` ( 1 ... 2 ) ) ) | 
						
							| 26 | 23 25 | ax-mp |  |-  ( EEhil ` 2 ) = ( RR^ ` ( 1 ... 2 ) ) | 
						
							| 27 |  | fz12pr |  |-  ( 1 ... 2 ) = { 1 , 2 } | 
						
							| 28 | 27 1 | eqtr4i |  |-  ( 1 ... 2 ) = I | 
						
							| 29 | 28 | fveq2i |  |-  ( RR^ ` ( 1 ... 2 ) ) = ( RR^ ` I ) | 
						
							| 30 | 26 29 | eqtri |  |-  ( EEhil ` 2 ) = ( RR^ ` I ) | 
						
							| 31 | 2 30 | eqtr4i |  |-  E = ( EEhil ` 2 ) | 
						
							| 32 | 1 | oveq2i |  |-  ( RR ^m I ) = ( RR ^m { 1 , 2 } ) | 
						
							| 33 | 3 32 | eqtri |  |-  P = ( RR ^m { 1 , 2 } ) | 
						
							| 34 | 1 | xpeq1i |  |-  ( I X. { 0 } ) = ( { 1 , 2 } X. { 0 } ) | 
						
							| 35 | 5 34 | eqtri |  |-  .0. = ( { 1 , 2 } X. { 0 } ) | 
						
							| 36 | 31 33 7 35 | ehl2eudisval0 |  |-  ( X e. P -> ( X D .0. ) = ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) ) | 
						
							| 37 | 22 36 | syl |  |-  ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) -> ( X D .0. ) = ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) ) | 
						
							| 38 | 37 | breq1d |  |-  ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) -> ( ( X D .0. ) < R <-> ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < R ) ) | 
						
							| 39 |  | rpge0 |  |-  ( R e. RR+ -> 0 <_ R ) | 
						
							| 40 | 19 39 | sqrtsqd |  |-  ( R e. RR+ -> ( sqrt ` ( R ^ 2 ) ) = R ) | 
						
							| 41 | 40 | eqcomd |  |-  ( R e. RR+ -> R = ( sqrt ` ( R ^ 2 ) ) ) | 
						
							| 42 | 41 | adantl |  |-  ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) -> R = ( sqrt ` ( R ^ 2 ) ) ) | 
						
							| 43 | 42 | breq2d |  |-  ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) -> ( ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < R <-> ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < ( sqrt ` ( R ^ 2 ) ) ) ) | 
						
							| 44 | 43 | biimpa |  |-  ( ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) /\ ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < R ) -> ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < ( sqrt ` ( R ^ 2 ) ) ) | 
						
							| 45 | 22 8 | syl |  |-  ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) -> ( X ` 1 ) e. RR ) | 
						
							| 46 | 45 | adantr |  |-  ( ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) /\ ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < R ) -> ( X ` 1 ) e. RR ) | 
						
							| 47 | 46 | resqcld |  |-  ( ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) /\ ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < R ) -> ( ( X ` 1 ) ^ 2 ) e. RR ) | 
						
							| 48 | 22 9 | syl |  |-  ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) -> ( X ` 2 ) e. RR ) | 
						
							| 49 | 48 | adantr |  |-  ( ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) /\ ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < R ) -> ( X ` 2 ) e. RR ) | 
						
							| 50 | 49 | resqcld |  |-  ( ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) /\ ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < R ) -> ( ( X ` 2 ) ^ 2 ) e. RR ) | 
						
							| 51 | 47 50 | readdcld |  |-  ( ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) /\ ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < R ) -> ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) e. RR ) | 
						
							| 52 | 46 | sqge0d |  |-  ( ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) /\ ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < R ) -> 0 <_ ( ( X ` 1 ) ^ 2 ) ) | 
						
							| 53 | 49 | sqge0d |  |-  ( ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) /\ ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < R ) -> 0 <_ ( ( X ` 2 ) ^ 2 ) ) | 
						
							| 54 | 47 50 52 53 | addge0d |  |-  ( ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) /\ ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < R ) -> 0 <_ ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) | 
						
							| 55 | 19 | adantl |  |-  ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) -> R e. RR ) | 
						
							| 56 | 55 | adantr |  |-  ( ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) /\ ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < R ) -> R e. RR ) | 
						
							| 57 | 56 | resqcld |  |-  ( ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) /\ ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < R ) -> ( R ^ 2 ) e. RR ) | 
						
							| 58 | 56 | sqge0d |  |-  ( ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) /\ ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < R ) -> 0 <_ ( R ^ 2 ) ) | 
						
							| 59 | 51 54 57 58 | sqrtltd |  |-  ( ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) /\ ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < R ) -> ( ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) < ( R ^ 2 ) <-> ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < ( sqrt ` ( R ^ 2 ) ) ) ) | 
						
							| 60 | 44 59 | mpbird |  |-  ( ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) /\ ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < R ) -> ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) < ( R ^ 2 ) ) | 
						
							| 61 | 60 | ex |  |-  ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) -> ( ( sqrt ` ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) ) < R -> ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) < ( R ^ 2 ) ) ) | 
						
							| 62 | 38 61 | sylbid |  |-  ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ R e. RR+ ) -> ( ( X D .0. ) < R -> ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) < ( R ^ 2 ) ) ) | 
						
							| 63 | 62 | impr |  |-  ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ ( R e. RR+ /\ ( X D .0. ) < R ) ) -> ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) < ( R ^ 2 ) ) | 
						
							| 64 |  | eqid |  |-  ( ( Y ` 1 ) - ( X ` 1 ) ) = ( ( Y ` 1 ) - ( X ` 1 ) ) | 
						
							| 65 |  | eqid |  |-  ( ( X ` 2 ) - ( Y ` 2 ) ) = ( ( X ` 2 ) - ( Y ` 2 ) ) | 
						
							| 66 |  | eqid |  |-  ( ( ( X ` 2 ) x. ( Y ` 1 ) ) - ( ( X ` 1 ) x. ( Y ` 2 ) ) ) = ( ( ( X ` 2 ) x. ( Y ` 1 ) ) - ( ( X ` 1 ) x. ( Y ` 2 ) ) ) | 
						
							| 67 | 64 65 66 | itscnhlinecirc02plem2 |  |-  ( ( ( ( ( X ` 1 ) e. RR /\ ( X ` 2 ) e. RR ) /\ ( ( Y ` 1 ) e. RR /\ ( Y ` 2 ) e. RR ) /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ ( R e. RR /\ ( ( ( X ` 1 ) ^ 2 ) + ( ( X ` 2 ) ^ 2 ) ) < ( R ^ 2 ) ) ) -> 0 < ( ( -u ( 2 x. ( ( ( Y ` 1 ) - ( X ` 1 ) ) x. ( ( ( X ` 2 ) x. ( Y ` 1 ) ) - ( ( X ` 1 ) x. ( Y ` 2 ) ) ) ) ) ^ 2 ) - ( 4 x. ( ( ( ( ( X ` 2 ) - ( Y ` 2 ) ) ^ 2 ) + ( ( ( Y ` 1 ) - ( X ` 1 ) ) ^ 2 ) ) x. ( ( ( ( ( X ` 2 ) x. ( Y ` 1 ) ) - ( ( X ` 1 ) x. ( Y ` 2 ) ) ) ^ 2 ) - ( ( ( ( X ` 2 ) - ( Y ` 2 ) ) ^ 2 ) x. ( R ^ 2 ) ) ) ) ) ) ) | 
						
							| 68 | 12 17 18 21 63 67 | syl32anc |  |-  ( ( ( X e. P /\ Y e. P /\ ( X ` 2 ) =/= ( Y ` 2 ) ) /\ ( R e. RR+ /\ ( X D .0. ) < R ) ) -> 0 < ( ( -u ( 2 x. ( ( ( Y ` 1 ) - ( X ` 1 ) ) x. ( ( ( X ` 2 ) x. ( Y ` 1 ) ) - ( ( X ` 1 ) x. ( Y ` 2 ) ) ) ) ) ^ 2 ) - ( 4 x. ( ( ( ( ( X ` 2 ) - ( Y ` 2 ) ) ^ 2 ) + ( ( ( Y ` 1 ) - ( X ` 1 ) ) ^ 2 ) ) x. ( ( ( ( ( X ` 2 ) x. ( Y ` 1 ) ) - ( ( X ` 1 ) x. ( Y ` 2 ) ) ) ^ 2 ) - ( ( ( ( X ` 2 ) - ( Y ` 2 ) ) ^ 2 ) x. ( R ^ 2 ) ) ) ) ) ) ) |