| Step | Hyp | Ref | Expression | 
						
							| 1 |  | isrhmd.b | ⊢ 𝐵  =  ( Base ‘ 𝑅 ) | 
						
							| 2 |  | isrhmd.o | ⊢  1   =  ( 1r ‘ 𝑅 ) | 
						
							| 3 |  | isrhmd.n | ⊢ 𝑁  =  ( 1r ‘ 𝑆 ) | 
						
							| 4 |  | isrhmd.t | ⊢  ·   =  ( .r ‘ 𝑅 ) | 
						
							| 5 |  | isrhmd.u | ⊢  ×   =  ( .r ‘ 𝑆 ) | 
						
							| 6 |  | isrhmd.r | ⊢ ( 𝜑  →  𝑅  ∈  Ring ) | 
						
							| 7 |  | isrhmd.s | ⊢ ( 𝜑  →  𝑆  ∈  Ring ) | 
						
							| 8 |  | isrhmd.ho | ⊢ ( 𝜑  →  ( 𝐹 ‘  1  )  =  𝑁 ) | 
						
							| 9 |  | isrhmd.ht | ⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵 ) )  →  ( 𝐹 ‘ ( 𝑥  ·  𝑦 ) )  =  ( ( 𝐹 ‘ 𝑥 )  ×  ( 𝐹 ‘ 𝑦 ) ) ) | 
						
							| 10 |  | isrhmd.c | ⊢ 𝐶  =  ( Base ‘ 𝑆 ) | 
						
							| 11 |  | isrhmd.p | ⊢  +   =  ( +g ‘ 𝑅 ) | 
						
							| 12 |  | isrhmd.q | ⊢  ⨣   =  ( +g ‘ 𝑆 ) | 
						
							| 13 |  | isrhmd.f | ⊢ ( 𝜑  →  𝐹 : 𝐵 ⟶ 𝐶 ) | 
						
							| 14 |  | isrhmd.hp | ⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵 ) )  →  ( 𝐹 ‘ ( 𝑥  +  𝑦 ) )  =  ( ( 𝐹 ‘ 𝑥 )  ⨣  ( 𝐹 ‘ 𝑦 ) ) ) | 
						
							| 15 |  | ringgrp | ⊢ ( 𝑅  ∈  Ring  →  𝑅  ∈  Grp ) | 
						
							| 16 | 6 15 | syl | ⊢ ( 𝜑  →  𝑅  ∈  Grp ) | 
						
							| 17 |  | ringgrp | ⊢ ( 𝑆  ∈  Ring  →  𝑆  ∈  Grp ) | 
						
							| 18 | 7 17 | syl | ⊢ ( 𝜑  →  𝑆  ∈  Grp ) | 
						
							| 19 | 1 10 11 12 16 18 13 14 | isghmd | ⊢ ( 𝜑  →  𝐹  ∈  ( 𝑅  GrpHom  𝑆 ) ) | 
						
							| 20 | 1 2 3 4 5 6 7 8 9 19 | isrhm2d | ⊢ ( 𝜑  →  𝐹  ∈  ( 𝑅  RingHom  𝑆 ) ) |