| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							funcringcsetc.r | 
							⊢ 𝑅  =  ( RingCat ‘ 𝑈 )  | 
						
						
							| 2 | 
							
								
							 | 
							funcringcsetc.s | 
							⊢ 𝑆  =  ( SetCat ‘ 𝑈 )  | 
						
						
							| 3 | 
							
								
							 | 
							funcringcsetc.b | 
							⊢ 𝐵  =  ( Base ‘ 𝑅 )  | 
						
						
							| 4 | 
							
								
							 | 
							funcringcsetc.u | 
							⊢ ( 𝜑  →  𝑈  ∈  WUni )  | 
						
						
							| 5 | 
							
								
							 | 
							funcringcsetc.f | 
							⊢ ( 𝜑  →  𝐹  =  ( 𝑥  ∈  𝐵  ↦  ( Base ‘ 𝑥 ) ) )  | 
						
						
							| 6 | 
							
								
							 | 
							funcringcsetc.g | 
							⊢ ( 𝜑  →  𝐺  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  (  I   ↾  ( 𝑥  RingHom  𝑦 ) ) ) )  | 
						
						
							| 7 | 
							
								
							 | 
							eqid | 
							⊢ ( ExtStrCat ‘ 𝑈 )  =  ( ExtStrCat ‘ 𝑈 )  | 
						
						
							| 8 | 
							
								
							 | 
							eqid | 
							⊢ ( Base ‘ ( ExtStrCat ‘ 𝑈 ) )  =  ( Base ‘ ( ExtStrCat ‘ 𝑈 ) )  | 
						
						
							| 9 | 
							
								
							 | 
							eqid | 
							⊢ ( Base ‘ 𝑆 )  =  ( Base ‘ 𝑆 )  | 
						
						
							| 10 | 
							
								7 4
							 | 
							estrcbas | 
							⊢ ( 𝜑  →  𝑈  =  ( Base ‘ ( ExtStrCat ‘ 𝑈 ) ) )  | 
						
						
							| 11 | 
							
								10
							 | 
							mpteq1d | 
							⊢ ( 𝜑  →  ( 𝑥  ∈  𝑈  ↦  ( Base ‘ 𝑥 ) )  =  ( 𝑥  ∈  ( Base ‘ ( ExtStrCat ‘ 𝑈 ) )  ↦  ( Base ‘ 𝑥 ) ) )  | 
						
						
							| 12 | 
							
								
							 | 
							mpoeq12 | 
							⊢ ( ( 𝑈  =  ( Base ‘ ( ExtStrCat ‘ 𝑈 ) )  ∧  𝑈  =  ( Base ‘ ( ExtStrCat ‘ 𝑈 ) ) )  →  ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) )  =  ( 𝑥  ∈  ( Base ‘ ( ExtStrCat ‘ 𝑈 ) ) ,  𝑦  ∈  ( Base ‘ ( ExtStrCat ‘ 𝑈 ) )  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) ) )  | 
						
						
							| 13 | 
							
								10 10 12
							 | 
							syl2anc | 
							⊢ ( 𝜑  →  ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) )  =  ( 𝑥  ∈  ( Base ‘ ( ExtStrCat ‘ 𝑈 ) ) ,  𝑦  ∈  ( Base ‘ ( ExtStrCat ‘ 𝑈 ) )  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) ) )  | 
						
						
							| 14 | 
							
								7 2 8 9 4 11 13
							 | 
							funcestrcsetc | 
							⊢ ( 𝜑  →  ( 𝑥  ∈  𝑈  ↦  ( Base ‘ 𝑥 ) ) ( ( ExtStrCat ‘ 𝑈 )  Func  𝑆 ) ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) ) )  | 
						
						
							| 15 | 
							
								
							 | 
							df-br | 
							⊢ ( ( 𝑥  ∈  𝑈  ↦  ( Base ‘ 𝑥 ) ) ( ( ExtStrCat ‘ 𝑈 )  Func  𝑆 ) ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) )  ↔  〈 ( 𝑥  ∈  𝑈  ↦  ( Base ‘ 𝑥 ) ) ,  ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) ) 〉  ∈  ( ( ExtStrCat ‘ 𝑈 )  Func  𝑆 ) )  | 
						
						
							| 16 | 
							
								14 15
							 | 
							sylib | 
							⊢ ( 𝜑  →  〈 ( 𝑥  ∈  𝑈  ↦  ( Base ‘ 𝑥 ) ) ,  ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) ) 〉  ∈  ( ( ExtStrCat ‘ 𝑈 )  Func  𝑆 ) )  | 
						
						
							| 17 | 
							
								
							 | 
							eqid | 
							⊢ ( Base ‘ 𝑅 )  =  ( Base ‘ 𝑅 )  | 
						
						
							| 18 | 
							
								1 17 4
							 | 
							ringcbas | 
							⊢ ( 𝜑  →  ( Base ‘ 𝑅 )  =  ( 𝑈  ∩  Ring ) )  | 
						
						
							| 19 | 
							
								
							 | 
							incom | 
							⊢ ( 𝑈  ∩  Ring )  =  ( Ring  ∩  𝑈 )  | 
						
						
							| 20 | 
							
								18 19
							 | 
							eqtrdi | 
							⊢ ( 𝜑  →  ( Base ‘ 𝑅 )  =  ( Ring  ∩  𝑈 ) )  | 
						
						
							| 21 | 
							
								
							 | 
							eqid | 
							⊢ ( Hom  ‘ 𝑅 )  =  ( Hom  ‘ 𝑅 )  | 
						
						
							| 22 | 
							
								1 17 4 21
							 | 
							ringchomfval | 
							⊢ ( 𝜑  →  ( Hom  ‘ 𝑅 )  =  (  RingHom   ↾  ( ( Base ‘ 𝑅 )  ×  ( Base ‘ 𝑅 ) ) ) )  | 
						
						
							| 23 | 
							
								7 4 20 22
							 | 
							rhmsubcsetc | 
							⊢ ( 𝜑  →  ( Hom  ‘ 𝑅 )  ∈  ( Subcat ‘ ( ExtStrCat ‘ 𝑈 ) ) )  | 
						
						
							| 24 | 
							
								16 23
							 | 
							funcres | 
							⊢ ( 𝜑  →  ( 〈 ( 𝑥  ∈  𝑈  ↦  ( Base ‘ 𝑥 ) ) ,  ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) ) 〉  ↾f  ( Hom  ‘ 𝑅 ) )  ∈  ( ( ( ExtStrCat ‘ 𝑈 )  ↾cat  ( Hom  ‘ 𝑅 ) )  Func  𝑆 ) )  | 
						
						
							| 25 | 
							
								
							 | 
							mptexg | 
							⊢ ( 𝑈  ∈  WUni  →  ( 𝑥  ∈  𝑈  ↦  ( Base ‘ 𝑥 ) )  ∈  V )  | 
						
						
							| 26 | 
							
								4 25
							 | 
							syl | 
							⊢ ( 𝜑  →  ( 𝑥  ∈  𝑈  ↦  ( Base ‘ 𝑥 ) )  ∈  V )  | 
						
						
							| 27 | 
							
								
							 | 
							fvex | 
							⊢ ( Hom  ‘ 𝑅 )  ∈  V  | 
						
						
							| 28 | 
							
								27
							 | 
							a1i | 
							⊢ ( 𝜑  →  ( Hom  ‘ 𝑅 )  ∈  V )  | 
						
						
							| 29 | 
							
								
							 | 
							mpoexga | 
							⊢ ( ( 𝑈  ∈  WUni  ∧  𝑈  ∈  WUni )  →  ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) )  ∈  V )  | 
						
						
							| 30 | 
							
								4 4 29
							 | 
							syl2anc | 
							⊢ ( 𝜑  →  ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) )  ∈  V )  | 
						
						
							| 31 | 
							
								18 22
							 | 
							rhmresfn | 
							⊢ ( 𝜑  →  ( Hom  ‘ 𝑅 )  Fn  ( ( Base ‘ 𝑅 )  ×  ( Base ‘ 𝑅 ) ) )  | 
						
						
							| 32 | 
							
								26 28 30 31
							 | 
							resfval2 | 
							⊢ ( 𝜑  →  ( 〈 ( 𝑥  ∈  𝑈  ↦  ( Base ‘ 𝑥 ) ) ,  ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) ) 〉  ↾f  ( Hom  ‘ 𝑅 ) )  =  〈 ( ( 𝑥  ∈  𝑈  ↦  ( Base ‘ 𝑥 ) )  ↾  ( Base ‘ 𝑅 ) ) ,  ( 𝑎  ∈  ( Base ‘ 𝑅 ) ,  𝑏  ∈  ( Base ‘ 𝑅 )  ↦  ( ( 𝑎 ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) ) 𝑏 )  ↾  ( 𝑎 ( Hom  ‘ 𝑅 ) 𝑏 ) ) ) 〉 )  | 
						
						
							| 33 | 
							
								
							 | 
							inss1 | 
							⊢ ( 𝑈  ∩  Ring )  ⊆  𝑈  | 
						
						
							| 34 | 
							
								18 33
							 | 
							eqsstrdi | 
							⊢ ( 𝜑  →  ( Base ‘ 𝑅 )  ⊆  𝑈 )  | 
						
						
							| 35 | 
							
								34
							 | 
							resmptd | 
							⊢ ( 𝜑  →  ( ( 𝑥  ∈  𝑈  ↦  ( Base ‘ 𝑥 ) )  ↾  ( Base ‘ 𝑅 ) )  =  ( 𝑥  ∈  ( Base ‘ 𝑅 )  ↦  ( Base ‘ 𝑥 ) ) )  | 
						
						
							| 36 | 
							
								3
							 | 
							a1i | 
							⊢ ( 𝜑  →  𝐵  =  ( Base ‘ 𝑅 ) )  | 
						
						
							| 37 | 
							
								36
							 | 
							mpteq1d | 
							⊢ ( 𝜑  →  ( 𝑥  ∈  𝐵  ↦  ( Base ‘ 𝑥 ) )  =  ( 𝑥  ∈  ( Base ‘ 𝑅 )  ↦  ( Base ‘ 𝑥 ) ) )  | 
						
						
							| 38 | 
							
								5 37
							 | 
							eqtr2d | 
							⊢ ( 𝜑  →  ( 𝑥  ∈  ( Base ‘ 𝑅 )  ↦  ( Base ‘ 𝑥 ) )  =  𝐹 )  | 
						
						
							| 39 | 
							
								35 38
							 | 
							eqtrd | 
							⊢ ( 𝜑  →  ( ( 𝑥  ∈  𝑈  ↦  ( Base ‘ 𝑥 ) )  ↾  ( Base ‘ 𝑅 ) )  =  𝐹 )  | 
						
						
							| 40 | 
							
								
							 | 
							oveq1 | 
							⊢ ( 𝑥  =  𝑎  →  ( 𝑥  RingHom  𝑦 )  =  ( 𝑎  RingHom  𝑦 ) )  | 
						
						
							| 41 | 
							
								40
							 | 
							reseq2d | 
							⊢ ( 𝑥  =  𝑎  →  (  I   ↾  ( 𝑥  RingHom  𝑦 ) )  =  (  I   ↾  ( 𝑎  RingHom  𝑦 ) ) )  | 
						
						
							| 42 | 
							
								
							 | 
							oveq2 | 
							⊢ ( 𝑦  =  𝑏  →  ( 𝑎  RingHom  𝑦 )  =  ( 𝑎  RingHom  𝑏 ) )  | 
						
						
							| 43 | 
							
								42
							 | 
							reseq2d | 
							⊢ ( 𝑦  =  𝑏  →  (  I   ↾  ( 𝑎  RingHom  𝑦 ) )  =  (  I   ↾  ( 𝑎  RingHom  𝑏 ) ) )  | 
						
						
							| 44 | 
							
								41 43
							 | 
							cbvmpov | 
							⊢ ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  (  I   ↾  ( 𝑥  RingHom  𝑦 ) ) )  =  ( 𝑎  ∈  𝐵 ,  𝑏  ∈  𝐵  ↦  (  I   ↾  ( 𝑎  RingHom  𝑏 ) ) )  | 
						
						
							| 45 | 
							
								44
							 | 
							a1i | 
							⊢ ( 𝜑  →  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  (  I   ↾  ( 𝑥  RingHom  𝑦 ) ) )  =  ( 𝑎  ∈  𝐵 ,  𝑏  ∈  𝐵  ↦  (  I   ↾  ( 𝑎  RingHom  𝑏 ) ) ) )  | 
						
						
							| 46 | 
							
								3
							 | 
							a1i | 
							⊢ ( ( 𝜑  ∧  𝑎  ∈  𝐵 )  →  𝐵  =  ( Base ‘ 𝑅 ) )  | 
						
						
							| 47 | 
							
								
							 | 
							eqidd | 
							⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) )  =  ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) ) )  | 
						
						
							| 48 | 
							
								
							 | 
							fveq2 | 
							⊢ ( 𝑦  =  𝑏  →  ( Base ‘ 𝑦 )  =  ( Base ‘ 𝑏 ) )  | 
						
						
							| 49 | 
							
								
							 | 
							fveq2 | 
							⊢ ( 𝑥  =  𝑎  →  ( Base ‘ 𝑥 )  =  ( Base ‘ 𝑎 ) )  | 
						
						
							| 50 | 
							
								48 49
							 | 
							oveqan12rd | 
							⊢ ( ( 𝑥  =  𝑎  ∧  𝑦  =  𝑏 )  →  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) )  =  ( ( Base ‘ 𝑏 )  ↑m  ( Base ‘ 𝑎 ) ) )  | 
						
						
							| 51 | 
							
								50
							 | 
							reseq2d | 
							⊢ ( ( 𝑥  =  𝑎  ∧  𝑦  =  𝑏 )  →  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) )  =  (  I   ↾  ( ( Base ‘ 𝑏 )  ↑m  ( Base ‘ 𝑎 ) ) ) )  | 
						
						
							| 52 | 
							
								51
							 | 
							adantl | 
							⊢ ( ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  ∧  ( 𝑥  =  𝑎  ∧  𝑦  =  𝑏 ) )  →  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) )  =  (  I   ↾  ( ( Base ‘ 𝑏 )  ↑m  ( Base ‘ 𝑎 ) ) ) )  | 
						
						
							| 53 | 
							
								3 34
							 | 
							eqsstrid | 
							⊢ ( 𝜑  →  𝐵  ⊆  𝑈 )  | 
						
						
							| 54 | 
							
								53
							 | 
							sseld | 
							⊢ ( 𝜑  →  ( 𝑎  ∈  𝐵  →  𝑎  ∈  𝑈 ) )  | 
						
						
							| 55 | 
							
								54
							 | 
							com12 | 
							⊢ ( 𝑎  ∈  𝐵  →  ( 𝜑  →  𝑎  ∈  𝑈 ) )  | 
						
						
							| 56 | 
							
								55
							 | 
							adantr | 
							⊢ ( ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 )  →  ( 𝜑  →  𝑎  ∈  𝑈 ) )  | 
						
						
							| 57 | 
							
								56
							 | 
							impcom | 
							⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  𝑎  ∈  𝑈 )  | 
						
						
							| 58 | 
							
								53
							 | 
							sseld | 
							⊢ ( 𝜑  →  ( 𝑏  ∈  𝐵  →  𝑏  ∈  𝑈 ) )  | 
						
						
							| 59 | 
							
								58
							 | 
							adantld | 
							⊢ ( 𝜑  →  ( ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 )  →  𝑏  ∈  𝑈 ) )  | 
						
						
							| 60 | 
							
								59
							 | 
							imp | 
							⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  𝑏  ∈  𝑈 )  | 
						
						
							| 61 | 
							
								
							 | 
							ovexd | 
							⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  ( ( Base ‘ 𝑏 )  ↑m  ( Base ‘ 𝑎 ) )  ∈  V )  | 
						
						
							| 62 | 
							
								61
							 | 
							resiexd | 
							⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  (  I   ↾  ( ( Base ‘ 𝑏 )  ↑m  ( Base ‘ 𝑎 ) ) )  ∈  V )  | 
						
						
							| 63 | 
							
								47 52 57 60 62
							 | 
							ovmpod | 
							⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  ( 𝑎 ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) ) 𝑏 )  =  (  I   ↾  ( ( Base ‘ 𝑏 )  ↑m  ( Base ‘ 𝑎 ) ) ) )  | 
						
						
							| 64 | 
							
								63
							 | 
							reseq1d | 
							⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  ( ( 𝑎 ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) ) 𝑏 )  ↾  ( 𝑎 ( Hom  ‘ 𝑅 ) 𝑏 ) )  =  ( (  I   ↾  ( ( Base ‘ 𝑏 )  ↑m  ( Base ‘ 𝑎 ) ) )  ↾  ( 𝑎 ( Hom  ‘ 𝑅 ) 𝑏 ) ) )  | 
						
						
							| 65 | 
							
								4
							 | 
							adantr | 
							⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  𝑈  ∈  WUni )  | 
						
						
							| 66 | 
							
								
							 | 
							simprl | 
							⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  𝑎  ∈  𝐵 )  | 
						
						
							| 67 | 
							
								
							 | 
							simprr | 
							⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  𝑏  ∈  𝐵 )  | 
						
						
							| 68 | 
							
								1 3 65 21 66 67
							 | 
							ringchom | 
							⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  ( 𝑎 ( Hom  ‘ 𝑅 ) 𝑏 )  =  ( 𝑎  RingHom  𝑏 ) )  | 
						
						
							| 69 | 
							
								68
							 | 
							reseq2d | 
							⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  ( (  I   ↾  ( ( Base ‘ 𝑏 )  ↑m  ( Base ‘ 𝑎 ) ) )  ↾  ( 𝑎 ( Hom  ‘ 𝑅 ) 𝑏 ) )  =  ( (  I   ↾  ( ( Base ‘ 𝑏 )  ↑m  ( Base ‘ 𝑎 ) ) )  ↾  ( 𝑎  RingHom  𝑏 ) ) )  | 
						
						
							| 70 | 
							
								
							 | 
							eqid | 
							⊢ ( Base ‘ 𝑎 )  =  ( Base ‘ 𝑎 )  | 
						
						
							| 71 | 
							
								
							 | 
							eqid | 
							⊢ ( Base ‘ 𝑏 )  =  ( Base ‘ 𝑏 )  | 
						
						
							| 72 | 
							
								70 71
							 | 
							rhmf | 
							⊢ ( 𝑓  ∈  ( 𝑎  RingHom  𝑏 )  →  𝑓 : ( Base ‘ 𝑎 ) ⟶ ( Base ‘ 𝑏 ) )  | 
						
						
							| 73 | 
							
								
							 | 
							fvex | 
							⊢ ( Base ‘ 𝑏 )  ∈  V  | 
						
						
							| 74 | 
							
								
							 | 
							fvex | 
							⊢ ( Base ‘ 𝑎 )  ∈  V  | 
						
						
							| 75 | 
							
								73 74
							 | 
							pm3.2i | 
							⊢ ( ( Base ‘ 𝑏 )  ∈  V  ∧  ( Base ‘ 𝑎 )  ∈  V )  | 
						
						
							| 76 | 
							
								75
							 | 
							a1i | 
							⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  ( ( Base ‘ 𝑏 )  ∈  V  ∧  ( Base ‘ 𝑎 )  ∈  V ) )  | 
						
						
							| 77 | 
							
								
							 | 
							elmapg | 
							⊢ ( ( ( Base ‘ 𝑏 )  ∈  V  ∧  ( Base ‘ 𝑎 )  ∈  V )  →  ( 𝑓  ∈  ( ( Base ‘ 𝑏 )  ↑m  ( Base ‘ 𝑎 ) )  ↔  𝑓 : ( Base ‘ 𝑎 ) ⟶ ( Base ‘ 𝑏 ) ) )  | 
						
						
							| 78 | 
							
								76 77
							 | 
							syl | 
							⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  ( 𝑓  ∈  ( ( Base ‘ 𝑏 )  ↑m  ( Base ‘ 𝑎 ) )  ↔  𝑓 : ( Base ‘ 𝑎 ) ⟶ ( Base ‘ 𝑏 ) ) )  | 
						
						
							| 79 | 
							
								72 78
							 | 
							imbitrrid | 
							⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  ( 𝑓  ∈  ( 𝑎  RingHom  𝑏 )  →  𝑓  ∈  ( ( Base ‘ 𝑏 )  ↑m  ( Base ‘ 𝑎 ) ) ) )  | 
						
						
							| 80 | 
							
								79
							 | 
							ssrdv | 
							⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  ( 𝑎  RingHom  𝑏 )  ⊆  ( ( Base ‘ 𝑏 )  ↑m  ( Base ‘ 𝑎 ) ) )  | 
						
						
							| 81 | 
							
								80
							 | 
							resabs1d | 
							⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  ( (  I   ↾  ( ( Base ‘ 𝑏 )  ↑m  ( Base ‘ 𝑎 ) ) )  ↾  ( 𝑎  RingHom  𝑏 ) )  =  (  I   ↾  ( 𝑎  RingHom  𝑏 ) ) )  | 
						
						
							| 82 | 
							
								64 69 81
							 | 
							3eqtrrd | 
							⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  (  I   ↾  ( 𝑎  RingHom  𝑏 ) )  =  ( ( 𝑎 ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) ) 𝑏 )  ↾  ( 𝑎 ( Hom  ‘ 𝑅 ) 𝑏 ) ) )  | 
						
						
							| 83 | 
							
								36 46 82
							 | 
							mpoeq123dva | 
							⊢ ( 𝜑  →  ( 𝑎  ∈  𝐵 ,  𝑏  ∈  𝐵  ↦  (  I   ↾  ( 𝑎  RingHom  𝑏 ) ) )  =  ( 𝑎  ∈  ( Base ‘ 𝑅 ) ,  𝑏  ∈  ( Base ‘ 𝑅 )  ↦  ( ( 𝑎 ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) ) 𝑏 )  ↾  ( 𝑎 ( Hom  ‘ 𝑅 ) 𝑏 ) ) ) )  | 
						
						
							| 84 | 
							
								6 45 83
							 | 
							3eqtrrd | 
							⊢ ( 𝜑  →  ( 𝑎  ∈  ( Base ‘ 𝑅 ) ,  𝑏  ∈  ( Base ‘ 𝑅 )  ↦  ( ( 𝑎 ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) ) 𝑏 )  ↾  ( 𝑎 ( Hom  ‘ 𝑅 ) 𝑏 ) ) )  =  𝐺 )  | 
						
						
							| 85 | 
							
								39 84
							 | 
							opeq12d | 
							⊢ ( 𝜑  →  〈 ( ( 𝑥  ∈  𝑈  ↦  ( Base ‘ 𝑥 ) )  ↾  ( Base ‘ 𝑅 ) ) ,  ( 𝑎  ∈  ( Base ‘ 𝑅 ) ,  𝑏  ∈  ( Base ‘ 𝑅 )  ↦  ( ( 𝑎 ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) ) 𝑏 )  ↾  ( 𝑎 ( Hom  ‘ 𝑅 ) 𝑏 ) ) ) 〉  =  〈 𝐹 ,  𝐺 〉 )  | 
						
						
							| 86 | 
							
								32 85
							 | 
							eqtr2d | 
							⊢ ( 𝜑  →  〈 𝐹 ,  𝐺 〉  =  ( 〈 ( 𝑥  ∈  𝑈  ↦  ( Base ‘ 𝑥 ) ) ,  ( 𝑥  ∈  𝑈 ,  𝑦  ∈  𝑈  ↦  (  I   ↾  ( ( Base ‘ 𝑦 )  ↑m  ( Base ‘ 𝑥 ) ) ) ) 〉  ↾f  ( Hom  ‘ 𝑅 ) ) )  | 
						
						
							| 87 | 
							
								1 4 18 22
							 | 
							ringcval | 
							⊢ ( 𝜑  →  𝑅  =  ( ( ExtStrCat ‘ 𝑈 )  ↾cat  ( Hom  ‘ 𝑅 ) ) )  | 
						
						
							| 88 | 
							
								87
							 | 
							oveq1d | 
							⊢ ( 𝜑  →  ( 𝑅  Func  𝑆 )  =  ( ( ( ExtStrCat ‘ 𝑈 )  ↾cat  ( Hom  ‘ 𝑅 ) )  Func  𝑆 ) )  | 
						
						
							| 89 | 
							
								24 86 88
							 | 
							3eltr4d | 
							⊢ ( 𝜑  →  〈 𝐹 ,  𝐺 〉  ∈  ( 𝑅  Func  𝑆 ) )  | 
						
						
							| 90 | 
							
								
							 | 
							df-br | 
							⊢ ( 𝐹 ( 𝑅  Func  𝑆 ) 𝐺  ↔  〈 𝐹 ,  𝐺 〉  ∈  ( 𝑅  Func  𝑆 ) )  | 
						
						
							| 91 | 
							
								89 90
							 | 
							sylibr | 
							⊢ ( 𝜑  →  𝐹 ( 𝑅  Func  𝑆 ) 𝐺 )  |