| 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 | ⊢  ·   =  ( .r ‘ 𝑅 ) | 
						
							| 8 |  | mdetuni.n | ⊢ ( 𝜑  →  𝑁  ∈  Fin ) | 
						
							| 9 |  | mdetuni.r | ⊢ ( 𝜑  →  𝑅  ∈  Ring ) | 
						
							| 10 |  | mdetuni.ff | ⊢ ( 𝜑  →  𝐷 : 𝐵 ⟶ 𝐾 ) | 
						
							| 11 |  | mdetuni.al | ⊢ ( 𝜑  →  ∀ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝑁 ∀ 𝑧  ∈  𝑁 ( ( 𝑦  ≠  𝑧  ∧  ∀ 𝑤  ∈  𝑁 ( 𝑦 𝑥 𝑤 )  =  ( 𝑧 𝑥 𝑤 ) )  →  ( 𝐷 ‘ 𝑥 )  =   0  ) ) | 
						
							| 12 |  | mdetuni.li | ⊢ ( 𝜑  →  ∀ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐵 ∀ 𝑧  ∈  𝐵 ∀ 𝑤  ∈  𝑁 ( ( ( 𝑥  ↾  ( { 𝑤 }  ×  𝑁 ) )  =  ( ( 𝑦  ↾  ( { 𝑤 }  ×  𝑁 ) )  ∘f   +  ( 𝑧  ↾  ( { 𝑤 }  ×  𝑁 ) ) )  ∧  ( 𝑥  ↾  ( ( 𝑁  ∖  { 𝑤 } )  ×  𝑁 ) )  =  ( 𝑦  ↾  ( ( 𝑁  ∖  { 𝑤 } )  ×  𝑁 ) )  ∧  ( 𝑥  ↾  ( ( 𝑁  ∖  { 𝑤 } )  ×  𝑁 ) )  =  ( 𝑧  ↾  ( ( 𝑁  ∖  { 𝑤 } )  ×  𝑁 ) ) )  →  ( 𝐷 ‘ 𝑥 )  =  ( ( 𝐷 ‘ 𝑦 )  +  ( 𝐷 ‘ 𝑧 ) ) ) ) | 
						
							| 13 |  | mdetuni.sc | ⊢ ( 𝜑  →  ∀ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐾 ∀ 𝑧  ∈  𝐵 ∀ 𝑤  ∈  𝑁 ( ( ( 𝑥  ↾  ( { 𝑤 }  ×  𝑁 ) )  =  ( ( ( { 𝑤 }  ×  𝑁 )  ×  { 𝑦 } )  ∘f   ·  ( 𝑧  ↾  ( { 𝑤 }  ×  𝑁 ) ) )  ∧  ( 𝑥  ↾  ( ( 𝑁  ∖  { 𝑤 } )  ×  𝑁 ) )  =  ( 𝑧  ↾  ( ( 𝑁  ∖  { 𝑤 } )  ×  𝑁 ) ) )  →  ( 𝐷 ‘ 𝑥 )  =  ( 𝑦  ·  ( 𝐷 ‘ 𝑧 ) ) ) ) | 
						
							| 14 |  | mdetunilem2.ph | ⊢ ( 𝜓  →  𝜑 ) | 
						
							| 15 |  | mdetunilem2.eg | ⊢ ( 𝜓  →  ( 𝐸  ∈  𝑁  ∧  𝐺  ∈  𝑁  ∧  𝐸  ≠  𝐺 ) ) | 
						
							| 16 |  | mdetunilem2.f | ⊢ ( ( 𝜓  ∧  𝑏  ∈  𝑁 )  →  𝐹  ∈  𝐾 ) | 
						
							| 17 |  | mdetunilem2.h | ⊢ ( ( 𝜓  ∧  𝑎  ∈  𝑁  ∧  𝑏  ∈  𝑁 )  →  𝐻  ∈  𝐾 ) | 
						
							| 18 | 14 8 | syl | ⊢ ( 𝜓  →  𝑁  ∈  Fin ) | 
						
							| 19 | 14 9 | syl | ⊢ ( 𝜓  →  𝑅  ∈  Ring ) | 
						
							| 20 | 16 | 3adant2 | ⊢ ( ( 𝜓  ∧  𝑎  ∈  𝑁  ∧  𝑏  ∈  𝑁 )  →  𝐹  ∈  𝐾 ) | 
						
							| 21 | 20 17 | ifcld | ⊢ ( ( 𝜓  ∧  𝑎  ∈  𝑁  ∧  𝑏  ∈  𝑁 )  →  if ( 𝑎  =  𝐺 ,  𝐹 ,  𝐻 )  ∈  𝐾 ) | 
						
							| 22 | 20 21 | ifcld | ⊢ ( ( 𝜓  ∧  𝑎  ∈  𝑁  ∧  𝑏  ∈  𝑁 )  →  if ( 𝑎  =  𝐸 ,  𝐹 ,  if ( 𝑎  =  𝐺 ,  𝐹 ,  𝐻 ) )  ∈  𝐾 ) | 
						
							| 23 | 1 3 2 18 19 22 | matbas2d | ⊢ ( 𝜓  →  ( 𝑎  ∈  𝑁 ,  𝑏  ∈  𝑁  ↦  if ( 𝑎  =  𝐸 ,  𝐹 ,  if ( 𝑎  =  𝐺 ,  𝐹 ,  𝐻 ) ) )  ∈  𝐵 ) | 
						
							| 24 |  | eqidd | ⊢ ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  →  ( 𝑎  ∈  𝑁 ,  𝑏  ∈  𝑁  ↦  if ( 𝑎  =  𝐸 ,  𝐹 ,  if ( 𝑎  =  𝐺 ,  𝐹 ,  𝐻 ) ) )  =  ( 𝑎  ∈  𝑁 ,  𝑏  ∈  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 | ⊢ ( ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  ∧  ( 𝑎  =  𝐸  ∧  𝑏  =  𝑤 ) )  →  if ( 𝑎  =  𝐸 ,  𝐹 ,  if ( 𝑎  =  𝐺 ,  𝐹 ,  𝐻 ) )  =  ⦋ 𝑤  /  𝑏 ⦌ 𝐹 ) | 
						
							| 29 |  | eqidd | ⊢ ( ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  ∧  𝑎  =  𝐸 )  →  𝑁  =  𝑁 ) | 
						
							| 30 | 15 | simp1d | ⊢ ( 𝜓  →  𝐸  ∈  𝑁 ) | 
						
							| 31 | 30 | adantr | ⊢ ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  →  𝐸  ∈  𝑁 ) | 
						
							| 32 |  | simpr | ⊢ ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  →  𝑤  ∈  𝑁 ) | 
						
							| 33 |  | nfv | ⊢ Ⅎ 𝑏 ( 𝜓  ∧  𝑤  ∈  𝑁 ) | 
						
							| 34 |  | nfcsb1v | ⊢ Ⅎ 𝑏 ⦋ 𝑤  /  𝑏 ⦌ 𝐹 | 
						
							| 35 | 34 | nfel1 | ⊢ Ⅎ 𝑏 ⦋ 𝑤  /  𝑏 ⦌ 𝐹  ∈  𝐾 | 
						
							| 36 | 33 35 | nfim | ⊢ Ⅎ 𝑏 ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  →  ⦋ 𝑤  /  𝑏 ⦌ 𝐹  ∈  𝐾 ) | 
						
							| 37 |  | eleq1w | ⊢ ( 𝑏  =  𝑤  →  ( 𝑏  ∈  𝑁  ↔  𝑤  ∈  𝑁 ) ) | 
						
							| 38 | 37 | anbi2d | ⊢ ( 𝑏  =  𝑤  →  ( ( 𝜓  ∧  𝑏  ∈  𝑁 )  ↔  ( 𝜓  ∧  𝑤  ∈  𝑁 ) ) ) | 
						
							| 39 | 26 | eleq1d | ⊢ ( 𝑏  =  𝑤  →  ( 𝐹  ∈  𝐾  ↔  ⦋ 𝑤  /  𝑏 ⦌ 𝐹  ∈  𝐾 ) ) | 
						
							| 40 | 38 39 | imbi12d | ⊢ ( 𝑏  =  𝑤  →  ( ( ( 𝜓  ∧  𝑏  ∈  𝑁 )  →  𝐹  ∈  𝐾 )  ↔  ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  →  ⦋ 𝑤  /  𝑏 ⦌ 𝐹  ∈  𝐾 ) ) ) | 
						
							| 41 | 36 40 16 | chvarfv | ⊢ ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  →  ⦋ 𝑤  /  𝑏 ⦌ 𝐹  ∈  𝐾 ) | 
						
							| 42 |  | nfv | ⊢ Ⅎ 𝑎 ( 𝜓  ∧  𝑤  ∈  𝑁 ) | 
						
							| 43 |  | nfcv | ⊢ Ⅎ 𝑏 𝐸 | 
						
							| 44 |  | nfcv | ⊢ Ⅎ 𝑎 𝑤 | 
						
							| 45 |  | nfcv | ⊢ Ⅎ 𝑎 ⦋ 𝑤  /  𝑏 ⦌ 𝐹 | 
						
							| 46 | 24 28 29 31 32 41 42 33 43 44 45 34 | ovmpodxf | ⊢ ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  →  ( 𝐸 ( 𝑎  ∈  𝑁 ,  𝑏  ∈  𝑁  ↦  if ( 𝑎  =  𝐸 ,  𝐹 ,  if ( 𝑎  =  𝐺 ,  𝐹 ,  𝐻 ) ) ) 𝑤 )  =  ⦋ 𝑤  /  𝑏 ⦌ 𝐹 ) | 
						
							| 47 | 15 | simp3d | ⊢ ( 𝜓  →  𝐸  ≠  𝐺 ) | 
						
							| 48 | 47 | adantr | ⊢ ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  →  𝐸  ≠  𝐺 ) | 
						
							| 49 |  | neeq2 | ⊢ ( 𝑎  =  𝐺  →  ( 𝐸  ≠  𝑎  ↔  𝐸  ≠  𝐺 ) ) | 
						
							| 50 | 48 49 | syl5ibrcom | ⊢ ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  →  ( 𝑎  =  𝐺  →  𝐸  ≠  𝑎 ) ) | 
						
							| 51 | 50 | imp | ⊢ ( ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  ∧  𝑎  =  𝐺 )  →  𝐸  ≠  𝑎 ) | 
						
							| 52 | 51 | necomd | ⊢ ( ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  ∧  𝑎  =  𝐺 )  →  𝑎  ≠  𝐸 ) | 
						
							| 53 | 52 | neneqd | ⊢ ( ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  ∧  𝑎  =  𝐺 )  →  ¬  𝑎  =  𝐸 ) | 
						
							| 54 | 53 | adantrr | ⊢ ( ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  ∧  ( 𝑎  =  𝐺  ∧  𝑏  =  𝑤 ) )  →  ¬  𝑎  =  𝐸 ) | 
						
							| 55 | 54 | iffalsed | ⊢ ( ( ( 𝜓  ∧  𝑤  ∈  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 | ⊢ ( ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  ∧  ( 𝑎  =  𝐺  ∧  𝑏  =  𝑤 ) )  →  if ( 𝑎  =  𝐺 ,  𝐹 ,  𝐻 )  =  ⦋ 𝑤  /  𝑏 ⦌ 𝐹 ) | 
						
							| 59 | 55 58 | eqtrd | ⊢ ( ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  ∧  ( 𝑎  =  𝐺  ∧  𝑏  =  𝑤 ) )  →  if ( 𝑎  =  𝐸 ,  𝐹 ,  if ( 𝑎  =  𝐺 ,  𝐹 ,  𝐻 ) )  =  ⦋ 𝑤  /  𝑏 ⦌ 𝐹 ) | 
						
							| 60 |  | eqidd | ⊢ ( ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  ∧  𝑎  =  𝐺 )  →  𝑁  =  𝑁 ) | 
						
							| 61 | 15 | simp2d | ⊢ ( 𝜓  →  𝐺  ∈  𝑁 ) | 
						
							| 62 | 61 | adantr | ⊢ ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  →  𝐺  ∈  𝑁 ) | 
						
							| 63 |  | nfcv | ⊢ Ⅎ 𝑏 𝐺 | 
						
							| 64 | 24 59 60 62 32 41 42 33 63 44 45 34 | ovmpodxf | ⊢ ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  →  ( 𝐺 ( 𝑎  ∈  𝑁 ,  𝑏  ∈  𝑁  ↦  if ( 𝑎  =  𝐸 ,  𝐹 ,  if ( 𝑎  =  𝐺 ,  𝐹 ,  𝐻 ) ) ) 𝑤 )  =  ⦋ 𝑤  /  𝑏 ⦌ 𝐹 ) | 
						
							| 65 | 46 64 | eqtr4d | ⊢ ( ( 𝜓  ∧  𝑤  ∈  𝑁 )  →  ( 𝐸 ( 𝑎  ∈  𝑁 ,  𝑏  ∈  𝑁  ↦  if ( 𝑎  =  𝐸 ,  𝐹 ,  if ( 𝑎  =  𝐺 ,  𝐹 ,  𝐻 ) ) ) 𝑤 )  =  ( 𝐺 ( 𝑎  ∈  𝑁 ,  𝑏  ∈  𝑁  ↦  if ( 𝑎  =  𝐸 ,  𝐹 ,  if ( 𝑎  =  𝐺 ,  𝐹 ,  𝐻 ) ) ) 𝑤 ) ) | 
						
							| 66 | 65 | ralrimiva | ⊢ ( 𝜓  →  ∀ 𝑤  ∈  𝑁 ( 𝐸 ( 𝑎  ∈  𝑁 ,  𝑏  ∈  𝑁  ↦  if ( 𝑎  =  𝐸 ,  𝐹 ,  if ( 𝑎  =  𝐺 ,  𝐹 ,  𝐻 ) ) ) 𝑤 )  =  ( 𝐺 ( 𝑎  ∈  𝑁 ,  𝑏  ∈  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 | ⊢ ( ( ( 𝜑  ∧  ( 𝑎  ∈  𝑁 ,  𝑏  ∈  𝑁  ↦  if ( 𝑎  =  𝐸 ,  𝐹 ,  if ( 𝑎  =  𝐺 ,  𝐹 ,  𝐻 ) ) )  ∈  𝐵  ∧  ∀ 𝑤  ∈  𝑁 ( 𝐸 ( 𝑎  ∈  𝑁 ,  𝑏  ∈  𝑁  ↦  if ( 𝑎  =  𝐸 ,  𝐹 ,  if ( 𝑎  =  𝐺 ,  𝐹 ,  𝐻 ) ) ) 𝑤 )  =  ( 𝐺 ( 𝑎  ∈  𝑁 ,  𝑏  ∈  𝑁  ↦  if ( 𝑎  =  𝐸 ,  𝐹 ,  if ( 𝑎  =  𝐺 ,  𝐹 ,  𝐻 ) ) ) 𝑤 ) )  ∧  ( 𝐸  ∈  𝑁  ∧  𝐺  ∈  𝑁  ∧  𝐸  ≠  𝐺 ) )  →  ( 𝐷 ‘ ( 𝑎  ∈  𝑁 ,  𝑏  ∈  𝑁  ↦  if ( 𝑎  =  𝐸 ,  𝐹 ,  if ( 𝑎  =  𝐺 ,  𝐹 ,  𝐻 ) ) ) )  =   0  ) | 
						
							| 68 | 14 23 66 15 67 | syl31anc | ⊢ ( 𝜓  →  ( 𝐷 ‘ ( 𝑎  ∈  𝑁 ,  𝑏  ∈  𝑁  ↦  if ( 𝑎  =  𝐸 ,  𝐹 ,  if ( 𝑎  =  𝐺 ,  𝐹 ,  𝐻 ) ) ) )  =   0  ) |