| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mdetuni.a |  |-  A = ( N Mat R ) | 
						
							| 2 |  | mdetuni.b |  |-  B = ( Base ` A ) | 
						
							| 3 |  | mdetuni.k |  |-  K = ( Base ` R ) | 
						
							| 4 |  | mdetuni.0g |  |-  .0. = ( 0g ` R ) | 
						
							| 5 |  | mdetuni.1r |  |-  .1. = ( 1r ` R ) | 
						
							| 6 |  | mdetuni.pg |  |-  .+ = ( +g ` R ) | 
						
							| 7 |  | mdetuni.tg |  |-  .x. = ( .r ` R ) | 
						
							| 8 |  | mdetuni.n |  |-  ( ph -> N e. Fin ) | 
						
							| 9 |  | mdetuni.r |  |-  ( ph -> R e. Ring ) | 
						
							| 10 |  | mdetuni.ff |  |-  ( ph -> D : B --> K ) | 
						
							| 11 |  | mdetuni.al |  |-  ( ph -> A. x e. B A. y e. N A. z e. N ( ( y =/= z /\ A. w e. N ( y x w ) = ( z x w ) ) -> ( D ` x ) = .0. ) ) | 
						
							| 12 |  | mdetuni.li |  |-  ( ph -> A. x e. B A. y e. B A. z e. B A. w e. N ( ( ( x |` ( { w } X. N ) ) = ( ( y |` ( { w } X. N ) ) oF .+ ( z |` ( { w } X. N ) ) ) /\ ( x |` ( ( N \ { w } ) X. N ) ) = ( y |` ( ( N \ { w } ) X. N ) ) /\ ( x |` ( ( N \ { w } ) X. N ) ) = ( z |` ( ( N \ { w } ) X. N ) ) ) -> ( D ` x ) = ( ( D ` y ) .+ ( D ` z ) ) ) ) | 
						
							| 13 |  | mdetuni.sc |  |-  ( ph -> A. x e. B A. y e. K A. z e. B A. w e. N ( ( ( x |` ( { w } X. N ) ) = ( ( ( { w } X. N ) X. { y } ) oF .x. ( z |` ( { w } X. N ) ) ) /\ ( x |` ( ( N \ { w } ) X. N ) ) = ( z |` ( ( N \ { w } ) X. N ) ) ) -> ( D ` x ) = ( y .x. ( D ` z ) ) ) ) | 
						
							| 14 |  | mdetunilem2.ph |  |-  ( ps -> ph ) | 
						
							| 15 |  | mdetunilem2.eg |  |-  ( ps -> ( E e. N /\ G e. N /\ E =/= G ) ) | 
						
							| 16 |  | mdetunilem2.f |  |-  ( ( ps /\ b e. N ) -> F e. K ) | 
						
							| 17 |  | mdetunilem2.h |  |-  ( ( ps /\ a e. N /\ b e. N ) -> H e. K ) | 
						
							| 18 | 14 8 | syl |  |-  ( ps -> N e. Fin ) | 
						
							| 19 | 14 9 | syl |  |-  ( ps -> R e. Ring ) | 
						
							| 20 | 16 | 3adant2 |  |-  ( ( ps /\ a e. N /\ b e. N ) -> F e. K ) | 
						
							| 21 | 20 17 | ifcld |  |-  ( ( ps /\ a e. N /\ b e. N ) -> if ( a = G , F , H ) e. K ) | 
						
							| 22 | 20 21 | ifcld |  |-  ( ( ps /\ a e. N /\ b e. N ) -> if ( a = E , F , if ( a = G , F , H ) ) e. K ) | 
						
							| 23 | 1 3 2 18 19 22 | matbas2d |  |-  ( ps -> ( a e. N , b e. N |-> if ( a = E , F , if ( a = G , F , H ) ) ) e. B ) | 
						
							| 24 |  | eqidd |  |-  ( ( ps /\ w e. N ) -> ( a e. N , b e. N |-> if ( a = E , F , if ( a = G , F , H ) ) ) = ( a e. N , b e. N |-> if ( a = E , F , if ( a = G , F , H ) ) ) ) | 
						
							| 25 |  | iftrue |  |-  ( a = E -> if ( a = E , F , if ( a = G , F , H ) ) = F ) | 
						
							| 26 |  | csbeq1a |  |-  ( b = w -> F = [_ w / b ]_ F ) | 
						
							| 27 | 25 26 | sylan9eq |  |-  ( ( a = E /\ b = w ) -> if ( a = E , F , if ( a = G , F , H ) ) = [_ w / b ]_ F ) | 
						
							| 28 | 27 | adantl |  |-  ( ( ( ps /\ w e. N ) /\ ( a = E /\ b = w ) ) -> if ( a = E , F , if ( a = G , F , H ) ) = [_ w / b ]_ F ) | 
						
							| 29 |  | eqidd |  |-  ( ( ( ps /\ w e. N ) /\ a = E ) -> N = N ) | 
						
							| 30 | 15 | simp1d |  |-  ( ps -> E e. N ) | 
						
							| 31 | 30 | adantr |  |-  ( ( ps /\ w e. N ) -> E e. N ) | 
						
							| 32 |  | simpr |  |-  ( ( ps /\ w e. N ) -> w e. N ) | 
						
							| 33 |  | nfv |  |-  F/ b ( ps /\ w e. N ) | 
						
							| 34 |  | nfcsb1v |  |-  F/_ b [_ w / b ]_ F | 
						
							| 35 | 34 | nfel1 |  |-  F/ b [_ w / b ]_ F e. K | 
						
							| 36 | 33 35 | nfim |  |-  F/ b ( ( ps /\ w e. N ) -> [_ w / b ]_ F e. K ) | 
						
							| 37 |  | eleq1w |  |-  ( b = w -> ( b e. N <-> w e. N ) ) | 
						
							| 38 | 37 | anbi2d |  |-  ( b = w -> ( ( ps /\ b e. N ) <-> ( ps /\ w e. N ) ) ) | 
						
							| 39 | 26 | eleq1d |  |-  ( b = w -> ( F e. K <-> [_ w / b ]_ F e. K ) ) | 
						
							| 40 | 38 39 | imbi12d |  |-  ( b = w -> ( ( ( ps /\ b e. N ) -> F e. K ) <-> ( ( ps /\ w e. N ) -> [_ w / b ]_ F e. K ) ) ) | 
						
							| 41 | 36 40 16 | chvarfv |  |-  ( ( ps /\ w e. N ) -> [_ w / b ]_ F e. K ) | 
						
							| 42 |  | nfv |  |-  F/ a ( ps /\ w e. N ) | 
						
							| 43 |  | nfcv |  |-  F/_ b E | 
						
							| 44 |  | nfcv |  |-  F/_ a w | 
						
							| 45 |  | nfcv |  |-  F/_ a [_ w / b ]_ F | 
						
							| 46 | 24 28 29 31 32 41 42 33 43 44 45 34 | ovmpodxf |  |-  ( ( ps /\ w e. N ) -> ( E ( a e. N , b e. N |-> if ( a = E , F , if ( a = G , F , H ) ) ) w ) = [_ w / b ]_ F ) | 
						
							| 47 | 15 | simp3d |  |-  ( ps -> E =/= G ) | 
						
							| 48 | 47 | adantr |  |-  ( ( ps /\ w e. N ) -> E =/= G ) | 
						
							| 49 |  | neeq2 |  |-  ( a = G -> ( E =/= a <-> E =/= G ) ) | 
						
							| 50 | 48 49 | syl5ibrcom |  |-  ( ( ps /\ w e. N ) -> ( a = G -> E =/= a ) ) | 
						
							| 51 | 50 | imp |  |-  ( ( ( ps /\ w e. N ) /\ a = G ) -> E =/= a ) | 
						
							| 52 | 51 | necomd |  |-  ( ( ( ps /\ w e. N ) /\ a = G ) -> a =/= E ) | 
						
							| 53 | 52 | neneqd |  |-  ( ( ( ps /\ w e. N ) /\ a = G ) -> -. a = E ) | 
						
							| 54 | 53 | adantrr |  |-  ( ( ( ps /\ w e. N ) /\ ( a = G /\ b = w ) ) -> -. a = E ) | 
						
							| 55 | 54 | iffalsed |  |-  ( ( ( ps /\ w e. N ) /\ ( a = G /\ b = w ) ) -> if ( a = E , F , if ( a = G , F , H ) ) = if ( a = G , F , H ) ) | 
						
							| 56 |  | iftrue |  |-  ( a = G -> if ( a = G , F , H ) = F ) | 
						
							| 57 | 56 26 | sylan9eq |  |-  ( ( a = G /\ b = w ) -> if ( a = G , F , H ) = [_ w / b ]_ F ) | 
						
							| 58 | 57 | adantl |  |-  ( ( ( ps /\ w e. N ) /\ ( a = G /\ b = w ) ) -> if ( a = G , F , H ) = [_ w / b ]_ F ) | 
						
							| 59 | 55 58 | eqtrd |  |-  ( ( ( ps /\ w e. N ) /\ ( a = G /\ b = w ) ) -> if ( a = E , F , if ( a = G , F , H ) ) = [_ w / b ]_ F ) | 
						
							| 60 |  | eqidd |  |-  ( ( ( ps /\ w e. N ) /\ a = G ) -> N = N ) | 
						
							| 61 | 15 | simp2d |  |-  ( ps -> G e. N ) | 
						
							| 62 | 61 | adantr |  |-  ( ( ps /\ w e. N ) -> G e. N ) | 
						
							| 63 |  | nfcv |  |-  F/_ b G | 
						
							| 64 | 24 59 60 62 32 41 42 33 63 44 45 34 | ovmpodxf |  |-  ( ( ps /\ w e. N ) -> ( G ( a e. N , b e. N |-> if ( a = E , F , if ( a = G , F , H ) ) ) w ) = [_ w / b ]_ F ) | 
						
							| 65 | 46 64 | eqtr4d |  |-  ( ( ps /\ w e. N ) -> ( E ( a e. N , b e. N |-> if ( a = E , F , if ( a = G , F , H ) ) ) w ) = ( G ( a e. N , b e. N |-> if ( a = E , F , if ( a = G , F , H ) ) ) w ) ) | 
						
							| 66 | 65 | ralrimiva |  |-  ( ps -> A. w e. N ( E ( a e. N , b e. N |-> if ( a = E , F , if ( a = G , F , H ) ) ) w ) = ( G ( a e. N , b e. N |-> if ( a = E , F , if ( a = G , F , H ) ) ) w ) ) | 
						
							| 67 | 1 2 3 4 5 6 7 8 9 10 11 12 13 | mdetunilem1 |  |-  ( ( ( ph /\ ( a e. N , b e. N |-> if ( a = E , F , if ( a = G , F , H ) ) ) e. B /\ A. w e. N ( E ( a e. N , b e. N |-> if ( a = E , F , if ( a = G , F , H ) ) ) w ) = ( G ( a e. N , b e. N |-> if ( a = E , F , if ( a = G , F , H ) ) ) w ) ) /\ ( E e. N /\ G e. N /\ E =/= G ) ) -> ( D ` ( a e. N , b e. N |-> if ( a = E , F , if ( a = G , F , H ) ) ) ) = .0. ) | 
						
							| 68 | 14 23 66 15 67 | syl31anc |  |-  ( ps -> ( D ` ( a e. N , b e. N |-> if ( a = E , F , if ( a = G , F , H ) ) ) ) = .0. ) |