| Step | Hyp | Ref | Expression | 
						
							| 0 |  | cmmul | ⊢  maMul | 
						
							| 1 |  | vr | ⊢ 𝑟 | 
						
							| 2 |  | cvv | ⊢ V | 
						
							| 3 |  | vo | ⊢ 𝑜 | 
						
							| 4 |  | c1st | ⊢ 1st | 
						
							| 5 | 3 | cv | ⊢ 𝑜 | 
						
							| 6 | 5 4 | cfv | ⊢ ( 1st  ‘ 𝑜 ) | 
						
							| 7 | 6 4 | cfv | ⊢ ( 1st  ‘ ( 1st  ‘ 𝑜 ) ) | 
						
							| 8 |  | vm | ⊢ 𝑚 | 
						
							| 9 |  | c2nd | ⊢ 2nd | 
						
							| 10 | 6 9 | cfv | ⊢ ( 2nd  ‘ ( 1st  ‘ 𝑜 ) ) | 
						
							| 11 |  | vn | ⊢ 𝑛 | 
						
							| 12 | 5 9 | cfv | ⊢ ( 2nd  ‘ 𝑜 ) | 
						
							| 13 |  | vp | ⊢ 𝑝 | 
						
							| 14 |  | vx | ⊢ 𝑥 | 
						
							| 15 |  | cbs | ⊢ Base | 
						
							| 16 | 1 | cv | ⊢ 𝑟 | 
						
							| 17 | 16 15 | cfv | ⊢ ( Base ‘ 𝑟 ) | 
						
							| 18 |  | cmap | ⊢  ↑m | 
						
							| 19 | 8 | cv | ⊢ 𝑚 | 
						
							| 20 | 11 | cv | ⊢ 𝑛 | 
						
							| 21 | 19 20 | cxp | ⊢ ( 𝑚  ×  𝑛 ) | 
						
							| 22 | 17 21 18 | co | ⊢ ( ( Base ‘ 𝑟 )  ↑m  ( 𝑚  ×  𝑛 ) ) | 
						
							| 23 |  | vy | ⊢ 𝑦 | 
						
							| 24 | 13 | cv | ⊢ 𝑝 | 
						
							| 25 | 20 24 | cxp | ⊢ ( 𝑛  ×  𝑝 ) | 
						
							| 26 | 17 25 18 | co | ⊢ ( ( Base ‘ 𝑟 )  ↑m  ( 𝑛  ×  𝑝 ) ) | 
						
							| 27 |  | vi | ⊢ 𝑖 | 
						
							| 28 |  | vk | ⊢ 𝑘 | 
						
							| 29 |  | cgsu | ⊢  Σg | 
						
							| 30 |  | vj | ⊢ 𝑗 | 
						
							| 31 | 27 | cv | ⊢ 𝑖 | 
						
							| 32 | 14 | cv | ⊢ 𝑥 | 
						
							| 33 | 30 | cv | ⊢ 𝑗 | 
						
							| 34 | 31 33 32 | co | ⊢ ( 𝑖 𝑥 𝑗 ) | 
						
							| 35 |  | cmulr | ⊢ .r | 
						
							| 36 | 16 35 | cfv | ⊢ ( .r ‘ 𝑟 ) | 
						
							| 37 | 23 | cv | ⊢ 𝑦 | 
						
							| 38 | 28 | cv | ⊢ 𝑘 | 
						
							| 39 | 33 38 37 | co | ⊢ ( 𝑗 𝑦 𝑘 ) | 
						
							| 40 | 34 39 36 | co | ⊢ ( ( 𝑖 𝑥 𝑗 ) ( .r ‘ 𝑟 ) ( 𝑗 𝑦 𝑘 ) ) | 
						
							| 41 | 30 20 40 | cmpt | ⊢ ( 𝑗  ∈  𝑛  ↦  ( ( 𝑖 𝑥 𝑗 ) ( .r ‘ 𝑟 ) ( 𝑗 𝑦 𝑘 ) ) ) | 
						
							| 42 | 16 41 29 | co | ⊢ ( 𝑟  Σg  ( 𝑗  ∈  𝑛  ↦  ( ( 𝑖 𝑥 𝑗 ) ( .r ‘ 𝑟 ) ( 𝑗 𝑦 𝑘 ) ) ) ) | 
						
							| 43 | 27 28 19 24 42 | cmpo | ⊢ ( 𝑖  ∈  𝑚 ,  𝑘  ∈  𝑝  ↦  ( 𝑟  Σg  ( 𝑗  ∈  𝑛  ↦  ( ( 𝑖 𝑥 𝑗 ) ( .r ‘ 𝑟 ) ( 𝑗 𝑦 𝑘 ) ) ) ) ) | 
						
							| 44 | 14 23 22 26 43 | cmpo | ⊢ ( 𝑥  ∈  ( ( Base ‘ 𝑟 )  ↑m  ( 𝑚  ×  𝑛 ) ) ,  𝑦  ∈  ( ( Base ‘ 𝑟 )  ↑m  ( 𝑛  ×  𝑝 ) )  ↦  ( 𝑖  ∈  𝑚 ,  𝑘  ∈  𝑝  ↦  ( 𝑟  Σg  ( 𝑗  ∈  𝑛  ↦  ( ( 𝑖 𝑥 𝑗 ) ( .r ‘ 𝑟 ) ( 𝑗 𝑦 𝑘 ) ) ) ) ) ) | 
						
							| 45 | 13 12 44 | csb | ⊢ ⦋ ( 2nd  ‘ 𝑜 )  /  𝑝 ⦌ ( 𝑥  ∈  ( ( Base ‘ 𝑟 )  ↑m  ( 𝑚  ×  𝑛 ) ) ,  𝑦  ∈  ( ( Base ‘ 𝑟 )  ↑m  ( 𝑛  ×  𝑝 ) )  ↦  ( 𝑖  ∈  𝑚 ,  𝑘  ∈  𝑝  ↦  ( 𝑟  Σg  ( 𝑗  ∈  𝑛  ↦  ( ( 𝑖 𝑥 𝑗 ) ( .r ‘ 𝑟 ) ( 𝑗 𝑦 𝑘 ) ) ) ) ) ) | 
						
							| 46 | 11 10 45 | csb | ⊢ ⦋ ( 2nd  ‘ ( 1st  ‘ 𝑜 ) )  /  𝑛 ⦌ ⦋ ( 2nd  ‘ 𝑜 )  /  𝑝 ⦌ ( 𝑥  ∈  ( ( Base ‘ 𝑟 )  ↑m  ( 𝑚  ×  𝑛 ) ) ,  𝑦  ∈  ( ( Base ‘ 𝑟 )  ↑m  ( 𝑛  ×  𝑝 ) )  ↦  ( 𝑖  ∈  𝑚 ,  𝑘  ∈  𝑝  ↦  ( 𝑟  Σg  ( 𝑗  ∈  𝑛  ↦  ( ( 𝑖 𝑥 𝑗 ) ( .r ‘ 𝑟 ) ( 𝑗 𝑦 𝑘 ) ) ) ) ) ) | 
						
							| 47 | 8 7 46 | csb | ⊢ ⦋ ( 1st  ‘ ( 1st  ‘ 𝑜 ) )  /  𝑚 ⦌ ⦋ ( 2nd  ‘ ( 1st  ‘ 𝑜 ) )  /  𝑛 ⦌ ⦋ ( 2nd  ‘ 𝑜 )  /  𝑝 ⦌ ( 𝑥  ∈  ( ( Base ‘ 𝑟 )  ↑m  ( 𝑚  ×  𝑛 ) ) ,  𝑦  ∈  ( ( Base ‘ 𝑟 )  ↑m  ( 𝑛  ×  𝑝 ) )  ↦  ( 𝑖  ∈  𝑚 ,  𝑘  ∈  𝑝  ↦  ( 𝑟  Σg  ( 𝑗  ∈  𝑛  ↦  ( ( 𝑖 𝑥 𝑗 ) ( .r ‘ 𝑟 ) ( 𝑗 𝑦 𝑘 ) ) ) ) ) ) | 
						
							| 48 | 1 3 2 2 47 | cmpo | ⊢ ( 𝑟  ∈  V ,  𝑜  ∈  V  ↦  ⦋ ( 1st  ‘ ( 1st  ‘ 𝑜 ) )  /  𝑚 ⦌ ⦋ ( 2nd  ‘ ( 1st  ‘ 𝑜 ) )  /  𝑛 ⦌ ⦋ ( 2nd  ‘ 𝑜 )  /  𝑝 ⦌ ( 𝑥  ∈  ( ( Base ‘ 𝑟 )  ↑m  ( 𝑚  ×  𝑛 ) ) ,  𝑦  ∈  ( ( Base ‘ 𝑟 )  ↑m  ( 𝑛  ×  𝑝 ) )  ↦  ( 𝑖  ∈  𝑚 ,  𝑘  ∈  𝑝  ↦  ( 𝑟  Σg  ( 𝑗  ∈  𝑛  ↦  ( ( 𝑖 𝑥 𝑗 ) ( .r ‘ 𝑟 ) ( 𝑗 𝑦 𝑘 ) ) ) ) ) ) ) | 
						
							| 49 | 0 48 | wceq | ⊢  maMul   =  ( 𝑟  ∈  V ,  𝑜  ∈  V  ↦  ⦋ ( 1st  ‘ ( 1st  ‘ 𝑜 ) )  /  𝑚 ⦌ ⦋ ( 2nd  ‘ ( 1st  ‘ 𝑜 ) )  /  𝑛 ⦌ ⦋ ( 2nd  ‘ 𝑜 )  /  𝑝 ⦌ ( 𝑥  ∈  ( ( Base ‘ 𝑟 )  ↑m  ( 𝑚  ×  𝑛 ) ) ,  𝑦  ∈  ( ( Base ‘ 𝑟 )  ↑m  ( 𝑛  ×  𝑝 ) )  ↦  ( 𝑖  ∈  𝑚 ,  𝑘  ∈  𝑝  ↦  ( 𝑟  Σg  ( 𝑗  ∈  𝑛  ↦  ( ( 𝑖 𝑥 𝑗 ) ( .r ‘ 𝑟 ) ( 𝑗 𝑦 𝑘 ) ) ) ) ) ) ) |