| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							mp2pm2mp.a | 
							⊢ 𝐴  =  ( 𝑁  Mat  𝑅 )  | 
						
						
							| 2 | 
							
								
							 | 
							mp2pm2mp.q | 
							⊢ 𝑄  =  ( Poly1 ‘ 𝐴 )  | 
						
						
							| 3 | 
							
								
							 | 
							mp2pm2mp.l | 
							⊢ 𝐿  =  ( Base ‘ 𝑄 )  | 
						
						
							| 4 | 
							
								
							 | 
							mp2pm2mp.m | 
							⊢  ·   =  (  ·𝑠  ‘ 𝑃 )  | 
						
						
							| 5 | 
							
								
							 | 
							mp2pm2mp.e | 
							⊢ 𝐸  =  ( .g ‘ ( mulGrp ‘ 𝑃 ) )  | 
						
						
							| 6 | 
							
								
							 | 
							mp2pm2mp.y | 
							⊢ 𝑌  =  ( var1 ‘ 𝑅 )  | 
						
						
							| 7 | 
							
								
							 | 
							mp2pm2mp.i | 
							⊢ 𝐼  =  ( 𝑝  ∈  𝐿  ↦  ( 𝑖  ∈  𝑁 ,  𝑗  ∈  𝑁  ↦  ( 𝑃  Σg  ( 𝑘  ∈  ℕ0  ↦  ( ( 𝑖 ( ( coe1 ‘ 𝑝 ) ‘ 𝑘 ) 𝑗 )  ·  ( 𝑘 𝐸 𝑌 ) ) ) ) ) )  | 
						
						
							| 8 | 
							
								
							 | 
							fveq2 | 
							⊢ ( 𝑝  =  𝑂  →  ( coe1 ‘ 𝑝 )  =  ( coe1 ‘ 𝑂 ) )  | 
						
						
							| 9 | 
							
								8
							 | 
							fveq1d | 
							⊢ ( 𝑝  =  𝑂  →  ( ( coe1 ‘ 𝑝 ) ‘ 𝑘 )  =  ( ( coe1 ‘ 𝑂 ) ‘ 𝑘 ) )  | 
						
						
							| 10 | 
							
								9
							 | 
							oveqd | 
							⊢ ( 𝑝  =  𝑂  →  ( 𝑖 ( ( coe1 ‘ 𝑝 ) ‘ 𝑘 ) 𝑗 )  =  ( 𝑖 ( ( coe1 ‘ 𝑂 ) ‘ 𝑘 ) 𝑗 ) )  | 
						
						
							| 11 | 
							
								10
							 | 
							oveq1d | 
							⊢ ( 𝑝  =  𝑂  →  ( ( 𝑖 ( ( coe1 ‘ 𝑝 ) ‘ 𝑘 ) 𝑗 )  ·  ( 𝑘 𝐸 𝑌 ) )  =  ( ( 𝑖 ( ( coe1 ‘ 𝑂 ) ‘ 𝑘 ) 𝑗 )  ·  ( 𝑘 𝐸 𝑌 ) ) )  | 
						
						
							| 12 | 
							
								11
							 | 
							mpteq2dv | 
							⊢ ( 𝑝  =  𝑂  →  ( 𝑘  ∈  ℕ0  ↦  ( ( 𝑖 ( ( coe1 ‘ 𝑝 ) ‘ 𝑘 ) 𝑗 )  ·  ( 𝑘 𝐸 𝑌 ) ) )  =  ( 𝑘  ∈  ℕ0  ↦  ( ( 𝑖 ( ( coe1 ‘ 𝑂 ) ‘ 𝑘 ) 𝑗 )  ·  ( 𝑘 𝐸 𝑌 ) ) ) )  | 
						
						
							| 13 | 
							
								12
							 | 
							oveq2d | 
							⊢ ( 𝑝  =  𝑂  →  ( 𝑃  Σg  ( 𝑘  ∈  ℕ0  ↦  ( ( 𝑖 ( ( coe1 ‘ 𝑝 ) ‘ 𝑘 ) 𝑗 )  ·  ( 𝑘 𝐸 𝑌 ) ) ) )  =  ( 𝑃  Σg  ( 𝑘  ∈  ℕ0  ↦  ( ( 𝑖 ( ( coe1 ‘ 𝑂 ) ‘ 𝑘 ) 𝑗 )  ·  ( 𝑘 𝐸 𝑌 ) ) ) ) )  | 
						
						
							| 14 | 
							
								13
							 | 
							mpoeq3dv | 
							⊢ ( 𝑝  =  𝑂  →  ( 𝑖  ∈  𝑁 ,  𝑗  ∈  𝑁  ↦  ( 𝑃  Σg  ( 𝑘  ∈  ℕ0  ↦  ( ( 𝑖 ( ( coe1 ‘ 𝑝 ) ‘ 𝑘 ) 𝑗 )  ·  ( 𝑘 𝐸 𝑌 ) ) ) ) )  =  ( 𝑖  ∈  𝑁 ,  𝑗  ∈  𝑁  ↦  ( 𝑃  Σg  ( 𝑘  ∈  ℕ0  ↦  ( ( 𝑖 ( ( coe1 ‘ 𝑂 ) ‘ 𝑘 ) 𝑗 )  ·  ( 𝑘 𝐸 𝑌 ) ) ) ) ) )  | 
						
						
							| 15 | 
							
								
							 | 
							simp3 | 
							⊢ ( ( 𝑁  ∈  Fin  ∧  𝑅  ∈  Ring  ∧  𝑂  ∈  𝐿 )  →  𝑂  ∈  𝐿 )  | 
						
						
							| 16 | 
							
								
							 | 
							simp1 | 
							⊢ ( ( 𝑁  ∈  Fin  ∧  𝑅  ∈  Ring  ∧  𝑂  ∈  𝐿 )  →  𝑁  ∈  Fin )  | 
						
						
							| 17 | 
							
								
							 | 
							mpoexga | 
							⊢ ( ( 𝑁  ∈  Fin  ∧  𝑁  ∈  Fin )  →  ( 𝑖  ∈  𝑁 ,  𝑗  ∈  𝑁  ↦  ( 𝑃  Σg  ( 𝑘  ∈  ℕ0  ↦  ( ( 𝑖 ( ( coe1 ‘ 𝑂 ) ‘ 𝑘 ) 𝑗 )  ·  ( 𝑘 𝐸 𝑌 ) ) ) ) )  ∈  V )  | 
						
						
							| 18 | 
							
								16 16 17
							 | 
							syl2anc | 
							⊢ ( ( 𝑁  ∈  Fin  ∧  𝑅  ∈  Ring  ∧  𝑂  ∈  𝐿 )  →  ( 𝑖  ∈  𝑁 ,  𝑗  ∈  𝑁  ↦  ( 𝑃  Σg  ( 𝑘  ∈  ℕ0  ↦  ( ( 𝑖 ( ( coe1 ‘ 𝑂 ) ‘ 𝑘 ) 𝑗 )  ·  ( 𝑘 𝐸 𝑌 ) ) ) ) )  ∈  V )  | 
						
						
							| 19 | 
							
								7 14 15 18
							 | 
							fvmptd3 | 
							⊢ ( ( 𝑁  ∈  Fin  ∧  𝑅  ∈  Ring  ∧  𝑂  ∈  𝐿 )  →  ( 𝐼 ‘ 𝑂 )  =  ( 𝑖  ∈  𝑁 ,  𝑗  ∈  𝑁  ↦  ( 𝑃  Σg  ( 𝑘  ∈  ℕ0  ↦  ( ( 𝑖 ( ( coe1 ‘ 𝑂 ) ‘ 𝑘 ) 𝑗 )  ·  ( 𝑘 𝐸 𝑌 ) ) ) ) ) )  |