| Step | Hyp | Ref | Expression | 
						
							| 1 |  | df-rhm | ⊢  RingHom   =  ( 𝑟  ∈  Ring ,  𝑠  ∈  Ring  ↦  ⦋ ( Base ‘ 𝑟 )  /  𝑣 ⦌ ⦋ ( Base ‘ 𝑠 )  /  𝑤 ⦌ { 𝑓  ∈  ( 𝑤  ↑m  𝑣 )  ∣  ( ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  𝑣 ∀ 𝑦  ∈  𝑣 ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) ) } ) | 
						
							| 2 |  | ancom | ⊢ ( ( ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) )  ↔  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) ) | 
						
							| 3 |  | r19.26-2 | ⊢ ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) )  ↔  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) ) | 
						
							| 4 | 3 | anbi1i | ⊢ ( ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) )  ↔  ( ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) ) | 
						
							| 5 |  | anass | ⊢ ( ( ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) )  ↔  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) ) ) | 
						
							| 6 | 2 4 5 | 3bitri | ⊢ ( ( ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) )  ↔  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) ) ) | 
						
							| 7 | 6 | rabbii | ⊢ { 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∣  ( ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) ) }  =  { 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∣  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) ) } | 
						
							| 8 |  | fvex | ⊢ ( Base ‘ 𝑟 )  ∈  V | 
						
							| 9 |  | fvex | ⊢ ( Base ‘ 𝑠 )  ∈  V | 
						
							| 10 |  | oveq12 | ⊢ ( ( 𝑤  =  ( Base ‘ 𝑠 )  ∧  𝑣  =  ( Base ‘ 𝑟 ) )  →  ( 𝑤  ↑m  𝑣 )  =  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) ) ) | 
						
							| 11 | 10 | ancoms | ⊢ ( ( 𝑣  =  ( Base ‘ 𝑟 )  ∧  𝑤  =  ( Base ‘ 𝑠 ) )  →  ( 𝑤  ↑m  𝑣 )  =  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) ) ) | 
						
							| 12 |  | raleq | ⊢ ( 𝑣  =  ( Base ‘ 𝑟 )  →  ( ∀ 𝑦  ∈  𝑣 ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) )  ↔  ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) ) ) | 
						
							| 13 | 12 | raleqbi1dv | ⊢ ( 𝑣  =  ( Base ‘ 𝑟 )  →  ( ∀ 𝑥  ∈  𝑣 ∀ 𝑦  ∈  𝑣 ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) )  ↔  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) ) ) | 
						
							| 14 | 13 | adantr | ⊢ ( ( 𝑣  =  ( Base ‘ 𝑟 )  ∧  𝑤  =  ( Base ‘ 𝑠 ) )  →  ( ∀ 𝑥  ∈  𝑣 ∀ 𝑦  ∈  𝑣 ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) )  ↔  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) ) ) | 
						
							| 15 | 14 | anbi2d | ⊢ ( ( 𝑣  =  ( Base ‘ 𝑟 )  ∧  𝑤  =  ( Base ‘ 𝑠 ) )  →  ( ( ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  𝑣 ∀ 𝑦  ∈  𝑣 ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) )  ↔  ( ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) ) ) ) | 
						
							| 16 | 11 15 | rabeqbidv | ⊢ ( ( 𝑣  =  ( Base ‘ 𝑟 )  ∧  𝑤  =  ( Base ‘ 𝑠 ) )  →  { 𝑓  ∈  ( 𝑤  ↑m  𝑣 )  ∣  ( ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  𝑣 ∀ 𝑦  ∈  𝑣 ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) ) }  =  { 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∣  ( ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) ) } ) | 
						
							| 17 | 8 9 16 | csbie2 | ⊢ ⦋ ( Base ‘ 𝑟 )  /  𝑣 ⦌ ⦋ ( Base ‘ 𝑠 )  /  𝑤 ⦌ { 𝑓  ∈  ( 𝑤  ↑m  𝑣 )  ∣  ( ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  𝑣 ∀ 𝑦  ∈  𝑣 ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) ) }  =  { 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∣  ( ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) ) } | 
						
							| 18 |  | inrab | ⊢ ( { 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∣  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) }  ∩  { 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∣  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) } )  =  { 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∣  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) ) } | 
						
							| 19 | 7 17 18 | 3eqtr4i | ⊢ ⦋ ( Base ‘ 𝑟 )  /  𝑣 ⦌ ⦋ ( Base ‘ 𝑠 )  /  𝑤 ⦌ { 𝑓  ∈  ( 𝑤  ↑m  𝑣 )  ∣  ( ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  𝑣 ∀ 𝑦  ∈  𝑣 ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) ) }  =  ( { 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∣  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) }  ∩  { 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∣  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) } ) | 
						
							| 20 |  | ringgrp | ⊢ ( 𝑟  ∈  Ring  →  𝑟  ∈  Grp ) | 
						
							| 21 |  | ringgrp | ⊢ ( 𝑠  ∈  Ring  →  𝑠  ∈  Grp ) | 
						
							| 22 |  | eqid | ⊢ ( Base ‘ 𝑟 )  =  ( Base ‘ 𝑟 ) | 
						
							| 23 |  | eqid | ⊢ ( Base ‘ 𝑠 )  =  ( Base ‘ 𝑠 ) | 
						
							| 24 |  | eqid | ⊢ ( +g ‘ 𝑟 )  =  ( +g ‘ 𝑟 ) | 
						
							| 25 |  | eqid | ⊢ ( +g ‘ 𝑠 )  =  ( +g ‘ 𝑠 ) | 
						
							| 26 | 22 23 24 25 | isghm3 | ⊢ ( ( 𝑟  ∈  Grp  ∧  𝑠  ∈  Grp )  →  ( 𝑓  ∈  ( 𝑟  GrpHom  𝑠 )  ↔  ( 𝑓 : ( Base ‘ 𝑟 ) ⟶ ( Base ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) ) ) | 
						
							| 27 | 20 21 26 | syl2an | ⊢ ( ( 𝑟  ∈  Ring  ∧  𝑠  ∈  Ring )  →  ( 𝑓  ∈  ( 𝑟  GrpHom  𝑠 )  ↔  ( 𝑓 : ( Base ‘ 𝑟 ) ⟶ ( Base ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) ) ) | 
						
							| 28 | 27 | eqabdv | ⊢ ( ( 𝑟  ∈  Ring  ∧  𝑠  ∈  Ring )  →  ( 𝑟  GrpHom  𝑠 )  =  { 𝑓  ∣  ( 𝑓 : ( Base ‘ 𝑟 ) ⟶ ( Base ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) } ) | 
						
							| 29 |  | df-rab | ⊢ { 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∣  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) }  =  { 𝑓  ∣  ( 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) } | 
						
							| 30 | 9 8 | elmap | ⊢ ( 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ↔  𝑓 : ( Base ‘ 𝑟 ) ⟶ ( Base ‘ 𝑠 ) ) | 
						
							| 31 | 30 | anbi1i | ⊢ ( ( 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) )  ↔  ( 𝑓 : ( Base ‘ 𝑟 ) ⟶ ( Base ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) ) | 
						
							| 32 | 31 | abbii | ⊢ { 𝑓  ∣  ( 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) }  =  { 𝑓  ∣  ( 𝑓 : ( Base ‘ 𝑟 ) ⟶ ( Base ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) } | 
						
							| 33 | 29 32 | eqtri | ⊢ { 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∣  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) }  =  { 𝑓  ∣  ( 𝑓 : ( Base ‘ 𝑟 ) ⟶ ( Base ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) } | 
						
							| 34 | 28 33 | eqtr4di | ⊢ ( ( 𝑟  ∈  Ring  ∧  𝑠  ∈  Ring )  →  ( 𝑟  GrpHom  𝑠 )  =  { 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∣  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) } ) | 
						
							| 35 |  | eqid | ⊢ ( mulGrp ‘ 𝑟 )  =  ( mulGrp ‘ 𝑟 ) | 
						
							| 36 | 35 | ringmgp | ⊢ ( 𝑟  ∈  Ring  →  ( mulGrp ‘ 𝑟 )  ∈  Mnd ) | 
						
							| 37 |  | eqid | ⊢ ( mulGrp ‘ 𝑠 )  =  ( mulGrp ‘ 𝑠 ) | 
						
							| 38 | 37 | ringmgp | ⊢ ( 𝑠  ∈  Ring  →  ( mulGrp ‘ 𝑠 )  ∈  Mnd ) | 
						
							| 39 | 35 22 | mgpbas | ⊢ ( Base ‘ 𝑟 )  =  ( Base ‘ ( mulGrp ‘ 𝑟 ) ) | 
						
							| 40 | 37 23 | mgpbas | ⊢ ( Base ‘ 𝑠 )  =  ( Base ‘ ( mulGrp ‘ 𝑠 ) ) | 
						
							| 41 |  | eqid | ⊢ ( .r ‘ 𝑟 )  =  ( .r ‘ 𝑟 ) | 
						
							| 42 | 35 41 | mgpplusg | ⊢ ( .r ‘ 𝑟 )  =  ( +g ‘ ( mulGrp ‘ 𝑟 ) ) | 
						
							| 43 |  | eqid | ⊢ ( .r ‘ 𝑠 )  =  ( .r ‘ 𝑠 ) | 
						
							| 44 | 37 43 | mgpplusg | ⊢ ( .r ‘ 𝑠 )  =  ( +g ‘ ( mulGrp ‘ 𝑠 ) ) | 
						
							| 45 |  | eqid | ⊢ ( 1r ‘ 𝑟 )  =  ( 1r ‘ 𝑟 ) | 
						
							| 46 | 35 45 | ringidval | ⊢ ( 1r ‘ 𝑟 )  =  ( 0g ‘ ( mulGrp ‘ 𝑟 ) ) | 
						
							| 47 |  | eqid | ⊢ ( 1r ‘ 𝑠 )  =  ( 1r ‘ 𝑠 ) | 
						
							| 48 | 37 47 | ringidval | ⊢ ( 1r ‘ 𝑠 )  =  ( 0g ‘ ( mulGrp ‘ 𝑠 ) ) | 
						
							| 49 | 39 40 42 44 46 48 | ismhm | ⊢ ( 𝑓  ∈  ( ( mulGrp ‘ 𝑟 )  MndHom  ( mulGrp ‘ 𝑠 ) )  ↔  ( ( ( mulGrp ‘ 𝑟 )  ∈  Mnd  ∧  ( mulGrp ‘ 𝑠 )  ∈  Mnd )  ∧  ( 𝑓 : ( Base ‘ 𝑟 ) ⟶ ( Base ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) ) ) | 
						
							| 50 | 49 | baib | ⊢ ( ( ( mulGrp ‘ 𝑟 )  ∈  Mnd  ∧  ( mulGrp ‘ 𝑠 )  ∈  Mnd )  →  ( 𝑓  ∈  ( ( mulGrp ‘ 𝑟 )  MndHom  ( mulGrp ‘ 𝑠 ) )  ↔  ( 𝑓 : ( Base ‘ 𝑟 ) ⟶ ( Base ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) ) ) | 
						
							| 51 | 36 38 50 | syl2an | ⊢ ( ( 𝑟  ∈  Ring  ∧  𝑠  ∈  Ring )  →  ( 𝑓  ∈  ( ( mulGrp ‘ 𝑟 )  MndHom  ( mulGrp ‘ 𝑠 ) )  ↔  ( 𝑓 : ( Base ‘ 𝑟 ) ⟶ ( Base ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) ) ) | 
						
							| 52 | 51 | eqabdv | ⊢ ( ( 𝑟  ∈  Ring  ∧  𝑠  ∈  Ring )  →  ( ( mulGrp ‘ 𝑟 )  MndHom  ( mulGrp ‘ 𝑠 ) )  =  { 𝑓  ∣  ( 𝑓 : ( Base ‘ 𝑟 ) ⟶ ( Base ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) } ) | 
						
							| 53 |  | df-rab | ⊢ { 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∣  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) }  =  { 𝑓  ∣  ( 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∧  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) ) } | 
						
							| 54 | 30 | anbi1i | ⊢ ( ( 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∧  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) )  ↔  ( 𝑓 : ( Base ‘ 𝑟 ) ⟶ ( Base ‘ 𝑠 )  ∧  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) ) ) | 
						
							| 55 |  | 3anass | ⊢ ( ( 𝑓 : ( Base ‘ 𝑟 ) ⟶ ( Base ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) )  ↔  ( 𝑓 : ( Base ‘ 𝑟 ) ⟶ ( Base ‘ 𝑠 )  ∧  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) ) ) | 
						
							| 56 | 54 55 | bitr4i | ⊢ ( ( 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∧  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) )  ↔  ( 𝑓 : ( Base ‘ 𝑟 ) ⟶ ( Base ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) ) | 
						
							| 57 | 56 | abbii | ⊢ { 𝑓  ∣  ( 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∧  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) ) }  =  { 𝑓  ∣  ( 𝑓 : ( Base ‘ 𝑟 ) ⟶ ( Base ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) } | 
						
							| 58 | 53 57 | eqtri | ⊢ { 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∣  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) }  =  { 𝑓  ∣  ( 𝑓 : ( Base ‘ 𝑟 ) ⟶ ( Base ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) } | 
						
							| 59 | 52 58 | eqtr4di | ⊢ ( ( 𝑟  ∈  Ring  ∧  𝑠  ∈  Ring )  →  ( ( mulGrp ‘ 𝑟 )  MndHom  ( mulGrp ‘ 𝑠 ) )  =  { 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∣  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) } ) | 
						
							| 60 | 34 59 | ineq12d | ⊢ ( ( 𝑟  ∈  Ring  ∧  𝑠  ∈  Ring )  →  ( ( 𝑟  GrpHom  𝑠 )  ∩  ( ( mulGrp ‘ 𝑟 )  MndHom  ( mulGrp ‘ 𝑠 ) ) )  =  ( { 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∣  ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) }  ∩  { 𝑓  ∈  ( ( Base ‘ 𝑠 )  ↑m  ( Base ‘ 𝑟 ) )  ∣  ( ∀ 𝑥  ∈  ( Base ‘ 𝑟 ) ∀ 𝑦  ∈  ( Base ‘ 𝑟 ) ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 ) ) } ) ) | 
						
							| 61 | 19 60 | eqtr4id | ⊢ ( ( 𝑟  ∈  Ring  ∧  𝑠  ∈  Ring )  →  ⦋ ( Base ‘ 𝑟 )  /  𝑣 ⦌ ⦋ ( Base ‘ 𝑠 )  /  𝑤 ⦌ { 𝑓  ∈  ( 𝑤  ↑m  𝑣 )  ∣  ( ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  𝑣 ∀ 𝑦  ∈  𝑣 ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) ) }  =  ( ( 𝑟  GrpHom  𝑠 )  ∩  ( ( mulGrp ‘ 𝑟 )  MndHom  ( mulGrp ‘ 𝑠 ) ) ) ) | 
						
							| 62 | 61 | mpoeq3ia | ⊢ ( 𝑟  ∈  Ring ,  𝑠  ∈  Ring  ↦  ⦋ ( Base ‘ 𝑟 )  /  𝑣 ⦌ ⦋ ( Base ‘ 𝑠 )  /  𝑤 ⦌ { 𝑓  ∈  ( 𝑤  ↑m  𝑣 )  ∣  ( ( 𝑓 ‘ ( 1r ‘ 𝑟 ) )  =  ( 1r ‘ 𝑠 )  ∧  ∀ 𝑥  ∈  𝑣 ∀ 𝑦  ∈  𝑣 ( ( 𝑓 ‘ ( 𝑥 ( +g ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( +g ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) )  ∧  ( 𝑓 ‘ ( 𝑥 ( .r ‘ 𝑟 ) 𝑦 ) )  =  ( ( 𝑓 ‘ 𝑥 ) ( .r ‘ 𝑠 ) ( 𝑓 ‘ 𝑦 ) ) ) ) } )  =  ( 𝑟  ∈  Ring ,  𝑠  ∈  Ring  ↦  ( ( 𝑟  GrpHom  𝑠 )  ∩  ( ( mulGrp ‘ 𝑟 )  MndHom  ( mulGrp ‘ 𝑠 ) ) ) ) | 
						
							| 63 | 1 62 | eqtri | ⊢  RingHom   =  ( 𝑟  ∈  Ring ,  𝑠  ∈  Ring  ↦  ( ( 𝑟  GrpHom  𝑠 )  ∩  ( ( mulGrp ‘ 𝑟 )  MndHom  ( mulGrp ‘ 𝑠 ) ) ) ) |