| Step | Hyp | Ref | Expression | 
						
							| 1 |  | fveq1 |  |-  ( A = C -> ( A ` i ) = ( C ` i ) ) | 
						
							| 2 | 1 | oveq2d |  |-  ( A = C -> ( T x. ( A ` i ) ) = ( T x. ( C ` i ) ) ) | 
						
							| 3 | 2 | oveq2d |  |-  ( A = C -> ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( A ` i ) ) ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( C ` i ) ) ) ) | 
						
							| 4 | 3 | eqeq2d |  |-  ( A = C -> ( ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( A ` i ) ) ) <-> ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( C ` i ) ) ) ) ) | 
						
							| 5 | 4 | ralbidv |  |-  ( A = C -> ( A. i e. ( 1 ... N ) ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( A ` i ) ) ) <-> A. i e. ( 1 ... N ) ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( C ` i ) ) ) ) ) | 
						
							| 6 | 5 | biimparc |  |-  ( ( A. i e. ( 1 ... N ) ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( C ` i ) ) ) /\ A = C ) -> A. i e. ( 1 ... N ) ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( A ` i ) ) ) ) | 
						
							| 7 |  | simplr1 |  |-  ( ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) /\ T e. ( 0 [,] 1 ) ) -> A e. ( EE ` N ) ) | 
						
							| 8 |  | simplr2 |  |-  ( ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) /\ T e. ( 0 [,] 1 ) ) -> B e. ( EE ` N ) ) | 
						
							| 9 |  | eqeefv |  |-  ( ( A e. ( EE ` N ) /\ B e. ( EE ` N ) ) -> ( A = B <-> A. i e. ( 1 ... N ) ( A ` i ) = ( B ` i ) ) ) | 
						
							| 10 | 7 8 9 | syl2anc |  |-  ( ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) /\ T e. ( 0 [,] 1 ) ) -> ( A = B <-> A. i e. ( 1 ... N ) ( A ` i ) = ( B ` i ) ) ) | 
						
							| 11 |  | fveecn |  |-  ( ( A e. ( EE ` N ) /\ i e. ( 1 ... N ) ) -> ( A ` i ) e. CC ) | 
						
							| 12 | 7 11 | sylan |  |-  ( ( ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) /\ T e. ( 0 [,] 1 ) ) /\ i e. ( 1 ... N ) ) -> ( A ` i ) e. CC ) | 
						
							| 13 |  | elicc01 |  |-  ( T e. ( 0 [,] 1 ) <-> ( T e. RR /\ 0 <_ T /\ T <_ 1 ) ) | 
						
							| 14 | 13 | simp1bi |  |-  ( T e. ( 0 [,] 1 ) -> T e. RR ) | 
						
							| 15 | 14 | recnd |  |-  ( T e. ( 0 [,] 1 ) -> T e. CC ) | 
						
							| 16 | 15 | ad2antlr |  |-  ( ( ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) /\ T e. ( 0 [,] 1 ) ) /\ i e. ( 1 ... N ) ) -> T e. CC ) | 
						
							| 17 |  | ax-1cn |  |-  1 e. CC | 
						
							| 18 |  | npcan |  |-  ( ( 1 e. CC /\ T e. CC ) -> ( ( 1 - T ) + T ) = 1 ) | 
						
							| 19 | 17 18 | mpan |  |-  ( T e. CC -> ( ( 1 - T ) + T ) = 1 ) | 
						
							| 20 | 19 | oveq1d |  |-  ( T e. CC -> ( ( ( 1 - T ) + T ) x. ( A ` i ) ) = ( 1 x. ( A ` i ) ) ) | 
						
							| 21 |  | mullid |  |-  ( ( A ` i ) e. CC -> ( 1 x. ( A ` i ) ) = ( A ` i ) ) | 
						
							| 22 | 20 21 | sylan9eqr |  |-  ( ( ( A ` i ) e. CC /\ T e. CC ) -> ( ( ( 1 - T ) + T ) x. ( A ` i ) ) = ( A ` i ) ) | 
						
							| 23 |  | subcl |  |-  ( ( 1 e. CC /\ T e. CC ) -> ( 1 - T ) e. CC ) | 
						
							| 24 | 17 23 | mpan |  |-  ( T e. CC -> ( 1 - T ) e. CC ) | 
						
							| 25 | 24 | adantl |  |-  ( ( ( A ` i ) e. CC /\ T e. CC ) -> ( 1 - T ) e. CC ) | 
						
							| 26 |  | simpr |  |-  ( ( ( A ` i ) e. CC /\ T e. CC ) -> T e. CC ) | 
						
							| 27 |  | simpl |  |-  ( ( ( A ` i ) e. CC /\ T e. CC ) -> ( A ` i ) e. CC ) | 
						
							| 28 | 25 26 27 | adddird |  |-  ( ( ( A ` i ) e. CC /\ T e. CC ) -> ( ( ( 1 - T ) + T ) x. ( A ` i ) ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( A ` i ) ) ) ) | 
						
							| 29 | 22 28 | eqtr3d |  |-  ( ( ( A ` i ) e. CC /\ T e. CC ) -> ( A ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( A ` i ) ) ) ) | 
						
							| 30 | 29 | eqeq1d |  |-  ( ( ( A ` i ) e. CC /\ T e. CC ) -> ( ( A ` i ) = ( B ` i ) <-> ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( A ` i ) ) ) = ( B ` i ) ) ) | 
						
							| 31 | 12 16 30 | syl2anc |  |-  ( ( ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) /\ T e. ( 0 [,] 1 ) ) /\ i e. ( 1 ... N ) ) -> ( ( A ` i ) = ( B ` i ) <-> ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( A ` i ) ) ) = ( B ` i ) ) ) | 
						
							| 32 |  | eqcom |  |-  ( ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( A ` i ) ) ) = ( B ` i ) <-> ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( A ` i ) ) ) ) | 
						
							| 33 | 31 32 | bitrdi |  |-  ( ( ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) /\ T e. ( 0 [,] 1 ) ) /\ i e. ( 1 ... N ) ) -> ( ( A ` i ) = ( B ` i ) <-> ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( A ` i ) ) ) ) ) | 
						
							| 34 | 33 | ralbidva |  |-  ( ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) /\ T e. ( 0 [,] 1 ) ) -> ( A. i e. ( 1 ... N ) ( A ` i ) = ( B ` i ) <-> A. i e. ( 1 ... N ) ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( A ` i ) ) ) ) ) | 
						
							| 35 | 10 34 | bitrd |  |-  ( ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) /\ T e. ( 0 [,] 1 ) ) -> ( A = B <-> A. i e. ( 1 ... N ) ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( A ` i ) ) ) ) ) | 
						
							| 36 | 6 35 | imbitrrid |  |-  ( ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) /\ T e. ( 0 [,] 1 ) ) -> ( ( A. i e. ( 1 ... N ) ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( C ` i ) ) ) /\ A = C ) -> A = B ) ) | 
						
							| 37 | 36 | expd |  |-  ( ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) /\ T e. ( 0 [,] 1 ) ) -> ( A. i e. ( 1 ... N ) ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( C ` i ) ) ) -> ( A = C -> A = B ) ) ) | 
						
							| 38 | 37 | impr |  |-  ( ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) /\ ( T e. ( 0 [,] 1 ) /\ A. i e. ( 1 ... N ) ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( C ` i ) ) ) ) ) -> ( A = C -> A = B ) ) | 
						
							| 39 | 38 | necon3d |  |-  ( ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) /\ ( T e. ( 0 [,] 1 ) /\ A. i e. ( 1 ... N ) ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( C ` i ) ) ) ) ) -> ( A =/= B -> A =/= C ) ) | 
						
							| 40 | 39 | ex |  |-  ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) -> ( ( T e. ( 0 [,] 1 ) /\ A. i e. ( 1 ... N ) ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( C ` i ) ) ) ) -> ( A =/= B -> A =/= C ) ) ) | 
						
							| 41 | 40 | com23 |  |-  ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) -> ( A =/= B -> ( ( T e. ( 0 [,] 1 ) /\ A. i e. ( 1 ... N ) ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( C ` i ) ) ) ) -> A =/= C ) ) ) | 
						
							| 42 | 41 | exp4a |  |-  ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) -> ( A =/= B -> ( T e. ( 0 [,] 1 ) -> ( A. i e. ( 1 ... N ) ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( C ` i ) ) ) -> A =/= C ) ) ) ) | 
						
							| 43 | 42 | 3imp2 |  |-  ( ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) /\ ( A =/= B /\ T e. ( 0 [,] 1 ) /\ A. i e. ( 1 ... N ) ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( C ` i ) ) ) ) ) -> A =/= C ) | 
						
							| 44 |  | simplr1 |  |-  ( ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) /\ ( A =/= B /\ T e. ( 0 [,] 1 ) /\ A. i e. ( 1 ... N ) ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( C ` i ) ) ) ) ) -> A e. ( EE ` N ) ) | 
						
							| 45 |  | simplr3 |  |-  ( ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) /\ ( A =/= B /\ T e. ( 0 [,] 1 ) /\ A. i e. ( 1 ... N ) ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( C ` i ) ) ) ) ) -> C e. ( EE ` N ) ) | 
						
							| 46 |  | eqeelen |  |-  ( ( A e. ( EE ` N ) /\ C e. ( EE ` N ) ) -> ( A = C <-> sum_ j e. ( 1 ... N ) ( ( ( A ` j ) - ( C ` j ) ) ^ 2 ) = 0 ) ) | 
						
							| 47 | 44 45 46 | syl2anc |  |-  ( ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) /\ ( A =/= B /\ T e. ( 0 [,] 1 ) /\ A. i e. ( 1 ... N ) ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( C ` i ) ) ) ) ) -> ( A = C <-> sum_ j e. ( 1 ... N ) ( ( ( A ` j ) - ( C ` j ) ) ^ 2 ) = 0 ) ) | 
						
							| 48 | 47 | necon3bid |  |-  ( ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) /\ ( A =/= B /\ T e. ( 0 [,] 1 ) /\ A. i e. ( 1 ... N ) ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( C ` i ) ) ) ) ) -> ( A =/= C <-> sum_ j e. ( 1 ... N ) ( ( ( A ` j ) - ( C ` j ) ) ^ 2 ) =/= 0 ) ) | 
						
							| 49 | 43 48 | mpbid |  |-  ( ( ( N e. NN /\ ( A e. ( EE ` N ) /\ B e. ( EE ` N ) /\ C e. ( EE ` N ) ) ) /\ ( A =/= B /\ T e. ( 0 [,] 1 ) /\ A. i e. ( 1 ... N ) ( B ` i ) = ( ( ( 1 - T ) x. ( A ` i ) ) + ( T x. ( C ` i ) ) ) ) ) -> sum_ j e. ( 1 ... N ) ( ( ( A ` j ) - ( C ` j ) ) ^ 2 ) =/= 0 ) |