| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							dprd2d.1 | 
							⊢ ( 𝜑  →  Rel  𝐴 )  | 
						
						
							| 2 | 
							
								
							 | 
							dprd2d.2 | 
							⊢ ( 𝜑  →  𝑆 : 𝐴 ⟶ ( SubGrp ‘ 𝐺 ) )  | 
						
						
							| 3 | 
							
								
							 | 
							dprd2d.3 | 
							⊢ ( 𝜑  →  dom  𝐴  ⊆  𝐼 )  | 
						
						
							| 4 | 
							
								
							 | 
							dprd2d.4 | 
							⊢ ( ( 𝜑  ∧  𝑖  ∈  𝐼 )  →  𝐺 dom   DProd  ( 𝑗  ∈  ( 𝐴  “  { 𝑖 } )  ↦  ( 𝑖 𝑆 𝑗 ) ) )  | 
						
						
							| 5 | 
							
								
							 | 
							dprd2d.5 | 
							⊢ ( 𝜑  →  𝐺 dom   DProd  ( 𝑖  ∈  𝐼  ↦  ( 𝐺  DProd  ( 𝑗  ∈  ( 𝐴  “  { 𝑖 } )  ↦  ( 𝑖 𝑆 𝑗 ) ) ) ) )  | 
						
						
							| 6 | 
							
								
							 | 
							dprd2d.k | 
							⊢ 𝐾  =  ( mrCls ‘ ( SubGrp ‘ 𝐺 ) )  | 
						
						
							| 7 | 
							
								
							 | 
							df-ov | 
							⊢ ( ( 1st  ‘ 𝑋 ) 𝑆 ( 2nd  ‘ 𝑋 ) )  =  ( 𝑆 ‘ 〈 ( 1st  ‘ 𝑋 ) ,  ( 2nd  ‘ 𝑋 ) 〉 )  | 
						
						
							| 8 | 
							
								
							 | 
							1st2nd | 
							⊢ ( ( Rel  𝐴  ∧  𝑋  ∈  𝐴 )  →  𝑋  =  〈 ( 1st  ‘ 𝑋 ) ,  ( 2nd  ‘ 𝑋 ) 〉 )  | 
						
						
							| 9 | 
							
								1 8
							 | 
							sylan | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  𝐴 )  →  𝑋  =  〈 ( 1st  ‘ 𝑋 ) ,  ( 2nd  ‘ 𝑋 ) 〉 )  | 
						
						
							| 10 | 
							
								
							 | 
							simpr | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  𝐴 )  →  𝑋  ∈  𝐴 )  | 
						
						
							| 11 | 
							
								9 10
							 | 
							eqeltrrd | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  𝐴 )  →  〈 ( 1st  ‘ 𝑋 ) ,  ( 2nd  ‘ 𝑋 ) 〉  ∈  𝐴 )  | 
						
						
							| 12 | 
							
								
							 | 
							df-br | 
							⊢ ( ( 1st  ‘ 𝑋 ) 𝐴 ( 2nd  ‘ 𝑋 )  ↔  〈 ( 1st  ‘ 𝑋 ) ,  ( 2nd  ‘ 𝑋 ) 〉  ∈  𝐴 )  | 
						
						
							| 13 | 
							
								11 12
							 | 
							sylibr | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  𝐴 )  →  ( 1st  ‘ 𝑋 ) 𝐴 ( 2nd  ‘ 𝑋 ) )  | 
						
						
							| 14 | 
							
								1
							 | 
							adantr | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  𝐴 )  →  Rel  𝐴 )  | 
						
						
							| 15 | 
							
								
							 | 
							elrelimasn | 
							⊢ ( Rel  𝐴  →  ( ( 2nd  ‘ 𝑋 )  ∈  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } )  ↔  ( 1st  ‘ 𝑋 ) 𝐴 ( 2nd  ‘ 𝑋 ) ) )  | 
						
						
							| 16 | 
							
								14 15
							 | 
							syl | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  𝐴 )  →  ( ( 2nd  ‘ 𝑋 )  ∈  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } )  ↔  ( 1st  ‘ 𝑋 ) 𝐴 ( 2nd  ‘ 𝑋 ) ) )  | 
						
						
							| 17 | 
							
								13 16
							 | 
							mpbird | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  𝐴 )  →  ( 2nd  ‘ 𝑋 )  ∈  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } ) )  | 
						
						
							| 18 | 
							
								
							 | 
							oveq2 | 
							⊢ ( 𝑗  =  ( 2nd  ‘ 𝑋 )  →  ( ( 1st  ‘ 𝑋 ) 𝑆 𝑗 )  =  ( ( 1st  ‘ 𝑋 ) 𝑆 ( 2nd  ‘ 𝑋 ) ) )  | 
						
						
							| 19 | 
							
								
							 | 
							eqid | 
							⊢ ( 𝑗  ∈  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } )  ↦  ( ( 1st  ‘ 𝑋 ) 𝑆 𝑗 ) )  =  ( 𝑗  ∈  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } )  ↦  ( ( 1st  ‘ 𝑋 ) 𝑆 𝑗 ) )  | 
						
						
							| 20 | 
							
								
							 | 
							ovex | 
							⊢ ( ( 1st  ‘ 𝑋 ) 𝑆 𝑗 )  ∈  V  | 
						
						
							| 21 | 
							
								18 19 20
							 | 
							fvmpt3i | 
							⊢ ( ( 2nd  ‘ 𝑋 )  ∈  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } )  →  ( ( 𝑗  ∈  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } )  ↦  ( ( 1st  ‘ 𝑋 ) 𝑆 𝑗 ) ) ‘ ( 2nd  ‘ 𝑋 ) )  =  ( ( 1st  ‘ 𝑋 ) 𝑆 ( 2nd  ‘ 𝑋 ) ) )  | 
						
						
							| 22 | 
							
								17 21
							 | 
							syl | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  𝐴 )  →  ( ( 𝑗  ∈  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } )  ↦  ( ( 1st  ‘ 𝑋 ) 𝑆 𝑗 ) ) ‘ ( 2nd  ‘ 𝑋 ) )  =  ( ( 1st  ‘ 𝑋 ) 𝑆 ( 2nd  ‘ 𝑋 ) ) )  | 
						
						
							| 23 | 
							
								9
							 | 
							fveq2d | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  𝐴 )  →  ( 𝑆 ‘ 𝑋 )  =  ( 𝑆 ‘ 〈 ( 1st  ‘ 𝑋 ) ,  ( 2nd  ‘ 𝑋 ) 〉 ) )  | 
						
						
							| 24 | 
							
								7 22 23
							 | 
							3eqtr4a | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  𝐴 )  →  ( ( 𝑗  ∈  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } )  ↦  ( ( 1st  ‘ 𝑋 ) 𝑆 𝑗 ) ) ‘ ( 2nd  ‘ 𝑋 ) )  =  ( 𝑆 ‘ 𝑋 ) )  | 
						
						
							| 25 | 
							
								
							 | 
							sneq | 
							⊢ ( 𝑖  =  ( 1st  ‘ 𝑋 )  →  { 𝑖 }  =  { ( 1st  ‘ 𝑋 ) } )  | 
						
						
							| 26 | 
							
								25
							 | 
							imaeq2d | 
							⊢ ( 𝑖  =  ( 1st  ‘ 𝑋 )  →  ( 𝐴  “  { 𝑖 } )  =  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } ) )  | 
						
						
							| 27 | 
							
								
							 | 
							oveq1 | 
							⊢ ( 𝑖  =  ( 1st  ‘ 𝑋 )  →  ( 𝑖 𝑆 𝑗 )  =  ( ( 1st  ‘ 𝑋 ) 𝑆 𝑗 ) )  | 
						
						
							| 28 | 
							
								26 27
							 | 
							mpteq12dv | 
							⊢ ( 𝑖  =  ( 1st  ‘ 𝑋 )  →  ( 𝑗  ∈  ( 𝐴  “  { 𝑖 } )  ↦  ( 𝑖 𝑆 𝑗 ) )  =  ( 𝑗  ∈  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } )  ↦  ( ( 1st  ‘ 𝑋 ) 𝑆 𝑗 ) ) )  | 
						
						
							| 29 | 
							
								28
							 | 
							breq2d | 
							⊢ ( 𝑖  =  ( 1st  ‘ 𝑋 )  →  ( 𝐺 dom   DProd  ( 𝑗  ∈  ( 𝐴  “  { 𝑖 } )  ↦  ( 𝑖 𝑆 𝑗 ) )  ↔  𝐺 dom   DProd  ( 𝑗  ∈  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } )  ↦  ( ( 1st  ‘ 𝑋 ) 𝑆 𝑗 ) ) ) )  | 
						
						
							| 30 | 
							
								4
							 | 
							ralrimiva | 
							⊢ ( 𝜑  →  ∀ 𝑖  ∈  𝐼 𝐺 dom   DProd  ( 𝑗  ∈  ( 𝐴  “  { 𝑖 } )  ↦  ( 𝑖 𝑆 𝑗 ) ) )  | 
						
						
							| 31 | 
							
								30
							 | 
							adantr | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  𝐴 )  →  ∀ 𝑖  ∈  𝐼 𝐺 dom   DProd  ( 𝑗  ∈  ( 𝐴  “  { 𝑖 } )  ↦  ( 𝑖 𝑆 𝑗 ) ) )  | 
						
						
							| 32 | 
							
								3
							 | 
							adantr | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  𝐴 )  →  dom  𝐴  ⊆  𝐼 )  | 
						
						
							| 33 | 
							
								
							 | 
							1stdm | 
							⊢ ( ( Rel  𝐴  ∧  𝑋  ∈  𝐴 )  →  ( 1st  ‘ 𝑋 )  ∈  dom  𝐴 )  | 
						
						
							| 34 | 
							
								1 33
							 | 
							sylan | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  𝐴 )  →  ( 1st  ‘ 𝑋 )  ∈  dom  𝐴 )  | 
						
						
							| 35 | 
							
								32 34
							 | 
							sseldd | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  𝐴 )  →  ( 1st  ‘ 𝑋 )  ∈  𝐼 )  | 
						
						
							| 36 | 
							
								29 31 35
							 | 
							rspcdva | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  𝐴 )  →  𝐺 dom   DProd  ( 𝑗  ∈  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } )  ↦  ( ( 1st  ‘ 𝑋 ) 𝑆 𝑗 ) ) )  | 
						
						
							| 37 | 
							
								20 19
							 | 
							dmmpti | 
							⊢ dom  ( 𝑗  ∈  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } )  ↦  ( ( 1st  ‘ 𝑋 ) 𝑆 𝑗 ) )  =  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } )  | 
						
						
							| 38 | 
							
								37
							 | 
							a1i | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  𝐴 )  →  dom  ( 𝑗  ∈  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } )  ↦  ( ( 1st  ‘ 𝑋 ) 𝑆 𝑗 ) )  =  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } ) )  | 
						
						
							| 39 | 
							
								36 38 17
							 | 
							dprdub | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  𝐴 )  →  ( ( 𝑗  ∈  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } )  ↦  ( ( 1st  ‘ 𝑋 ) 𝑆 𝑗 ) ) ‘ ( 2nd  ‘ 𝑋 ) )  ⊆  ( 𝐺  DProd  ( 𝑗  ∈  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } )  ↦  ( ( 1st  ‘ 𝑋 ) 𝑆 𝑗 ) ) ) )  | 
						
						
							| 40 | 
							
								24 39
							 | 
							eqsstrrd | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  𝐴 )  →  ( 𝑆 ‘ 𝑋 )  ⊆  ( 𝐺  DProd  ( 𝑗  ∈  ( 𝐴  “  { ( 1st  ‘ 𝑋 ) } )  ↦  ( ( 1st  ‘ 𝑋 ) 𝑆 𝑗 ) ) ) )  |