| Step | Hyp | Ref | Expression | 
						
							| 1 |  | rhmdvdsr.x | ⊢ 𝑋  =  ( Base ‘ 𝑅 ) | 
						
							| 2 |  | rhmdvdsr.m | ⊢  ∥   =  ( ∥r ‘ 𝑅 ) | 
						
							| 3 |  | rhmdvdsr.n | ⊢  /   =  ( ∥r ‘ 𝑆 ) | 
						
							| 4 |  | simpl1 | ⊢ ( ( ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  ∧  𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 )  ∧  𝐴  ∥  𝐵 )  →  𝐹  ∈  ( 𝑅  RingHom  𝑆 ) ) | 
						
							| 5 |  | simpl2 | ⊢ ( ( ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  ∧  𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 )  ∧  𝐴  ∥  𝐵 )  →  𝐴  ∈  𝑋 ) | 
						
							| 6 |  | eqid | ⊢ ( Base ‘ 𝑆 )  =  ( Base ‘ 𝑆 ) | 
						
							| 7 | 1 6 | rhmf | ⊢ ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  →  𝐹 : 𝑋 ⟶ ( Base ‘ 𝑆 ) ) | 
						
							| 8 | 7 | ffvelcdmda | ⊢ ( ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  ∧  𝐴  ∈  𝑋 )  →  ( 𝐹 ‘ 𝐴 )  ∈  ( Base ‘ 𝑆 ) ) | 
						
							| 9 | 4 5 8 | syl2anc | ⊢ ( ( ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  ∧  𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 )  ∧  𝐴  ∥  𝐵 )  →  ( 𝐹 ‘ 𝐴 )  ∈  ( Base ‘ 𝑆 ) ) | 
						
							| 10 |  | simpll1 | ⊢ ( ( ( ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  ∧  𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 )  ∧  𝐴  ∥  𝐵 )  ∧  𝑐  ∈  𝑋 )  →  𝐹  ∈  ( 𝑅  RingHom  𝑆 ) ) | 
						
							| 11 |  | simpr | ⊢ ( ( ( ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  ∧  𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 )  ∧  𝐴  ∥  𝐵 )  ∧  𝑐  ∈  𝑋 )  →  𝑐  ∈  𝑋 ) | 
						
							| 12 | 7 | ffvelcdmda | ⊢ ( ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  ∧  𝑐  ∈  𝑋 )  →  ( 𝐹 ‘ 𝑐 )  ∈  ( Base ‘ 𝑆 ) ) | 
						
							| 13 | 10 11 12 | syl2anc | ⊢ ( ( ( ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  ∧  𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 )  ∧  𝐴  ∥  𝐵 )  ∧  𝑐  ∈  𝑋 )  →  ( 𝐹 ‘ 𝑐 )  ∈  ( Base ‘ 𝑆 ) ) | 
						
							| 14 | 13 | ralrimiva | ⊢ ( ( ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  ∧  𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 )  ∧  𝐴  ∥  𝐵 )  →  ∀ 𝑐  ∈  𝑋 ( 𝐹 ‘ 𝑐 )  ∈  ( Base ‘ 𝑆 ) ) | 
						
							| 15 | 5 | adantr | ⊢ ( ( ( ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  ∧  𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 )  ∧  𝐴  ∥  𝐵 )  ∧  𝑐  ∈  𝑋 )  →  𝐴  ∈  𝑋 ) | 
						
							| 16 |  | eqid | ⊢ ( .r ‘ 𝑅 )  =  ( .r ‘ 𝑅 ) | 
						
							| 17 |  | eqid | ⊢ ( .r ‘ 𝑆 )  =  ( .r ‘ 𝑆 ) | 
						
							| 18 | 1 16 17 | rhmmul | ⊢ ( ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  ∧  𝑐  ∈  𝑋  ∧  𝐴  ∈  𝑋 )  →  ( 𝐹 ‘ ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 ) )  =  ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) ) ) | 
						
							| 19 | 10 11 15 18 | syl3anc | ⊢ ( ( ( ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  ∧  𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 )  ∧  𝐴  ∥  𝐵 )  ∧  𝑐  ∈  𝑋 )  →  ( 𝐹 ‘ ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 ) )  =  ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) ) ) | 
						
							| 20 | 19 | ralrimiva | ⊢ ( ( ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  ∧  𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 )  ∧  𝐴  ∥  𝐵 )  →  ∀ 𝑐  ∈  𝑋 ( 𝐹 ‘ ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 ) )  =  ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) ) ) | 
						
							| 21 |  | simpr | ⊢ ( ( ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  ∧  𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 )  ∧  𝐴  ∥  𝐵 )  →  𝐴  ∥  𝐵 ) | 
						
							| 22 | 1 2 16 | dvdsr2 | ⊢ ( 𝐴  ∈  𝑋  →  ( 𝐴  ∥  𝐵  ↔  ∃ 𝑐  ∈  𝑋 ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 )  =  𝐵 ) ) | 
						
							| 23 | 22 | biimpac | ⊢ ( ( 𝐴  ∥  𝐵  ∧  𝐴  ∈  𝑋 )  →  ∃ 𝑐  ∈  𝑋 ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 )  =  𝐵 ) | 
						
							| 24 | 21 5 23 | syl2anc | ⊢ ( ( ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  ∧  𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 )  ∧  𝐴  ∥  𝐵 )  →  ∃ 𝑐  ∈  𝑋 ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 )  =  𝐵 ) | 
						
							| 25 |  | r19.29 | ⊢ ( ( ∀ 𝑐  ∈  𝑋 ( 𝐹 ‘ ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 ) )  =  ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  ∧  ∃ 𝑐  ∈  𝑋 ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 )  =  𝐵 )  →  ∃ 𝑐  ∈  𝑋 ( ( 𝐹 ‘ ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 ) )  =  ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  ∧  ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 )  =  𝐵 ) ) | 
						
							| 26 |  | simpl | ⊢ ( ( ( 𝐹 ‘ ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 ) )  =  ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  ∧  ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 )  =  𝐵 )  →  ( 𝐹 ‘ ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 ) )  =  ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) ) ) | 
						
							| 27 |  | simpr | ⊢ ( ( ( 𝐹 ‘ ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 ) )  =  ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  ∧  ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 )  =  𝐵 )  →  ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 )  =  𝐵 ) | 
						
							| 28 | 27 | fveq2d | ⊢ ( ( ( 𝐹 ‘ ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 ) )  =  ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  ∧  ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 )  =  𝐵 )  →  ( 𝐹 ‘ ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 ) )  =  ( 𝐹 ‘ 𝐵 ) ) | 
						
							| 29 | 26 28 | eqtr3d | ⊢ ( ( ( 𝐹 ‘ ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 ) )  =  ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  ∧  ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 )  =  𝐵 )  →  ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  =  ( 𝐹 ‘ 𝐵 ) ) | 
						
							| 30 | 29 | reximi | ⊢ ( ∃ 𝑐  ∈  𝑋 ( ( 𝐹 ‘ ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 ) )  =  ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  ∧  ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 )  =  𝐵 )  →  ∃ 𝑐  ∈  𝑋 ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  =  ( 𝐹 ‘ 𝐵 ) ) | 
						
							| 31 | 25 30 | syl | ⊢ ( ( ∀ 𝑐  ∈  𝑋 ( 𝐹 ‘ ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 ) )  =  ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  ∧  ∃ 𝑐  ∈  𝑋 ( 𝑐 ( .r ‘ 𝑅 ) 𝐴 )  =  𝐵 )  →  ∃ 𝑐  ∈  𝑋 ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  =  ( 𝐹 ‘ 𝐵 ) ) | 
						
							| 32 | 20 24 31 | syl2anc | ⊢ ( ( ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  ∧  𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 )  ∧  𝐴  ∥  𝐵 )  →  ∃ 𝑐  ∈  𝑋 ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  =  ( 𝐹 ‘ 𝐵 ) ) | 
						
							| 33 |  | r19.29 | ⊢ ( ( ∀ 𝑐  ∈  𝑋 ( 𝐹 ‘ 𝑐 )  ∈  ( Base ‘ 𝑆 )  ∧  ∃ 𝑐  ∈  𝑋 ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  =  ( 𝐹 ‘ 𝐵 ) )  →  ∃ 𝑐  ∈  𝑋 ( ( 𝐹 ‘ 𝑐 )  ∈  ( Base ‘ 𝑆 )  ∧  ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  =  ( 𝐹 ‘ 𝐵 ) ) ) | 
						
							| 34 | 14 32 33 | syl2anc | ⊢ ( ( ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  ∧  𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 )  ∧  𝐴  ∥  𝐵 )  →  ∃ 𝑐  ∈  𝑋 ( ( 𝐹 ‘ 𝑐 )  ∈  ( Base ‘ 𝑆 )  ∧  ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  =  ( 𝐹 ‘ 𝐵 ) ) ) | 
						
							| 35 |  | oveq1 | ⊢ ( 𝑦  =  ( 𝐹 ‘ 𝑐 )  →  ( 𝑦 ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  =  ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) ) ) | 
						
							| 36 | 35 | eqeq1d | ⊢ ( 𝑦  =  ( 𝐹 ‘ 𝑐 )  →  ( ( 𝑦 ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  =  ( 𝐹 ‘ 𝐵 )  ↔  ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  =  ( 𝐹 ‘ 𝐵 ) ) ) | 
						
							| 37 | 36 | rspcev | ⊢ ( ( ( 𝐹 ‘ 𝑐 )  ∈  ( Base ‘ 𝑆 )  ∧  ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  =  ( 𝐹 ‘ 𝐵 ) )  →  ∃ 𝑦  ∈  ( Base ‘ 𝑆 ) ( 𝑦 ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  =  ( 𝐹 ‘ 𝐵 ) ) | 
						
							| 38 | 37 | rexlimivw | ⊢ ( ∃ 𝑐  ∈  𝑋 ( ( 𝐹 ‘ 𝑐 )  ∈  ( Base ‘ 𝑆 )  ∧  ( ( 𝐹 ‘ 𝑐 ) ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  =  ( 𝐹 ‘ 𝐵 ) )  →  ∃ 𝑦  ∈  ( Base ‘ 𝑆 ) ( 𝑦 ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  =  ( 𝐹 ‘ 𝐵 ) ) | 
						
							| 39 | 34 38 | syl | ⊢ ( ( ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  ∧  𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 )  ∧  𝐴  ∥  𝐵 )  →  ∃ 𝑦  ∈  ( Base ‘ 𝑆 ) ( 𝑦 ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  =  ( 𝐹 ‘ 𝐵 ) ) | 
						
							| 40 | 6 3 17 | dvdsr | ⊢ ( ( 𝐹 ‘ 𝐴 )  /  ( 𝐹 ‘ 𝐵 )  ↔  ( ( 𝐹 ‘ 𝐴 )  ∈  ( Base ‘ 𝑆 )  ∧  ∃ 𝑦  ∈  ( Base ‘ 𝑆 ) ( 𝑦 ( .r ‘ 𝑆 ) ( 𝐹 ‘ 𝐴 ) )  =  ( 𝐹 ‘ 𝐵 ) ) ) | 
						
							| 41 | 9 39 40 | sylanbrc | ⊢ ( ( ( 𝐹  ∈  ( 𝑅  RingHom  𝑆 )  ∧  𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 )  ∧  𝐴  ∥  𝐵 )  →  ( 𝐹 ‘ 𝐴 )  /  ( 𝐹 ‘ 𝐵 ) ) |