| Step | Hyp | Ref | Expression | 
						
							| 1 |  | dvdsr.1 | ⊢ 𝐵  =  ( Base ‘ 𝑅 ) | 
						
							| 2 |  | dvdsr.2 | ⊢  ∥   =  ( ∥r ‘ 𝑅 ) | 
						
							| 3 |  | eqid | ⊢ ( .r ‘ 𝑅 )  =  ( .r ‘ 𝑅 ) | 
						
							| 4 | 1 2 3 | dvdsr | ⊢ ( 𝑌  ∥  𝑍  ↔  ( 𝑌  ∈  𝐵  ∧  ∃ 𝑦  ∈  𝐵 ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 )  =  𝑍 ) ) | 
						
							| 5 | 1 2 3 | dvdsr | ⊢ ( 𝑍  ∥  𝑋  ↔  ( 𝑍  ∈  𝐵  ∧  ∃ 𝑥  ∈  𝐵 ( 𝑥 ( .r ‘ 𝑅 ) 𝑍 )  =  𝑋 ) ) | 
						
							| 6 | 4 5 | anbi12i | ⊢ ( ( 𝑌  ∥  𝑍  ∧  𝑍  ∥  𝑋 )  ↔  ( ( 𝑌  ∈  𝐵  ∧  ∃ 𝑦  ∈  𝐵 ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 )  =  𝑍 )  ∧  ( 𝑍  ∈  𝐵  ∧  ∃ 𝑥  ∈  𝐵 ( 𝑥 ( .r ‘ 𝑅 ) 𝑍 )  =  𝑋 ) ) ) | 
						
							| 7 |  | an4 | ⊢ ( ( ( 𝑌  ∈  𝐵  ∧  ∃ 𝑦  ∈  𝐵 ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 )  =  𝑍 )  ∧  ( 𝑍  ∈  𝐵  ∧  ∃ 𝑥  ∈  𝐵 ( 𝑥 ( .r ‘ 𝑅 ) 𝑍 )  =  𝑋 ) )  ↔  ( ( 𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  ∧  ( ∃ 𝑦  ∈  𝐵 ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 )  =  𝑍  ∧  ∃ 𝑥  ∈  𝐵 ( 𝑥 ( .r ‘ 𝑅 ) 𝑍 )  =  𝑋 ) ) ) | 
						
							| 8 | 6 7 | bitri | ⊢ ( ( 𝑌  ∥  𝑍  ∧  𝑍  ∥  𝑋 )  ↔  ( ( 𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  ∧  ( ∃ 𝑦  ∈  𝐵 ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 )  =  𝑍  ∧  ∃ 𝑥  ∈  𝐵 ( 𝑥 ( .r ‘ 𝑅 ) 𝑍 )  =  𝑋 ) ) ) | 
						
							| 9 |  | reeanv | ⊢ ( ∃ 𝑦  ∈  𝐵 ∃ 𝑥  ∈  𝐵 ( ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 )  =  𝑍  ∧  ( 𝑥 ( .r ‘ 𝑅 ) 𝑍 )  =  𝑋 )  ↔  ( ∃ 𝑦  ∈  𝐵 ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 )  =  𝑍  ∧  ∃ 𝑥  ∈  𝐵 ( 𝑥 ( .r ‘ 𝑅 ) 𝑍 )  =  𝑋 ) ) | 
						
							| 10 |  | simplrl | ⊢ ( ( ( 𝑅  ∈  Ring  ∧  ( 𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  ∧  ( 𝑦  ∈  𝐵  ∧  𝑥  ∈  𝐵 ) )  →  𝑌  ∈  𝐵 ) | 
						
							| 11 |  | simpll | ⊢ ( ( ( 𝑅  ∈  Ring  ∧  ( 𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  ∧  ( 𝑦  ∈  𝐵  ∧  𝑥  ∈  𝐵 ) )  →  𝑅  ∈  Ring ) | 
						
							| 12 |  | simprr | ⊢ ( ( ( 𝑅  ∈  Ring  ∧  ( 𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  ∧  ( 𝑦  ∈  𝐵  ∧  𝑥  ∈  𝐵 ) )  →  𝑥  ∈  𝐵 ) | 
						
							| 13 |  | simprl | ⊢ ( ( ( 𝑅  ∈  Ring  ∧  ( 𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  ∧  ( 𝑦  ∈  𝐵  ∧  𝑥  ∈  𝐵 ) )  →  𝑦  ∈  𝐵 ) | 
						
							| 14 | 1 3 | ringcl | ⊢ ( ( 𝑅  ∈  Ring  ∧  𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵 )  →  ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  ∈  𝐵 ) | 
						
							| 15 | 11 12 13 14 | syl3anc | ⊢ ( ( ( 𝑅  ∈  Ring  ∧  ( 𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  ∧  ( 𝑦  ∈  𝐵  ∧  𝑥  ∈  𝐵 ) )  →  ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  ∈  𝐵 ) | 
						
							| 16 | 1 2 3 | dvdsrmul | ⊢ ( ( 𝑌  ∈  𝐵  ∧  ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  ∈  𝐵 )  →  𝑌  ∥  ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 ) ( .r ‘ 𝑅 ) 𝑌 ) ) | 
						
							| 17 | 10 15 16 | syl2anc | ⊢ ( ( ( 𝑅  ∈  Ring  ∧  ( 𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  ∧  ( 𝑦  ∈  𝐵  ∧  𝑥  ∈  𝐵 ) )  →  𝑌  ∥  ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 ) ( .r ‘ 𝑅 ) 𝑌 ) ) | 
						
							| 18 | 1 3 | ringass | ⊢ ( ( 𝑅  ∈  Ring  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵  ∧  𝑌  ∈  𝐵 ) )  →  ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 ) ( .r ‘ 𝑅 ) 𝑌 )  =  ( 𝑥 ( .r ‘ 𝑅 ) ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 ) ) ) | 
						
							| 19 | 11 12 13 10 18 | syl13anc | ⊢ ( ( ( 𝑅  ∈  Ring  ∧  ( 𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  ∧  ( 𝑦  ∈  𝐵  ∧  𝑥  ∈  𝐵 ) )  →  ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 ) ( .r ‘ 𝑅 ) 𝑌 )  =  ( 𝑥 ( .r ‘ 𝑅 ) ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 ) ) ) | 
						
							| 20 | 17 19 | breqtrd | ⊢ ( ( ( 𝑅  ∈  Ring  ∧  ( 𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  ∧  ( 𝑦  ∈  𝐵  ∧  𝑥  ∈  𝐵 ) )  →  𝑌  ∥  ( 𝑥 ( .r ‘ 𝑅 ) ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 ) ) ) | 
						
							| 21 |  | oveq2 | ⊢ ( ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 )  =  𝑍  →  ( 𝑥 ( .r ‘ 𝑅 ) ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 ) )  =  ( 𝑥 ( .r ‘ 𝑅 ) 𝑍 ) ) | 
						
							| 22 |  | id | ⊢ ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑍 )  =  𝑋  →  ( 𝑥 ( .r ‘ 𝑅 ) 𝑍 )  =  𝑋 ) | 
						
							| 23 | 21 22 | sylan9eq | ⊢ ( ( ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 )  =  𝑍  ∧  ( 𝑥 ( .r ‘ 𝑅 ) 𝑍 )  =  𝑋 )  →  ( 𝑥 ( .r ‘ 𝑅 ) ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 ) )  =  𝑋 ) | 
						
							| 24 | 23 | breq2d | ⊢ ( ( ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 )  =  𝑍  ∧  ( 𝑥 ( .r ‘ 𝑅 ) 𝑍 )  =  𝑋 )  →  ( 𝑌  ∥  ( 𝑥 ( .r ‘ 𝑅 ) ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 ) )  ↔  𝑌  ∥  𝑋 ) ) | 
						
							| 25 | 20 24 | syl5ibcom | ⊢ ( ( ( 𝑅  ∈  Ring  ∧  ( 𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  ∧  ( 𝑦  ∈  𝐵  ∧  𝑥  ∈  𝐵 ) )  →  ( ( ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 )  =  𝑍  ∧  ( 𝑥 ( .r ‘ 𝑅 ) 𝑍 )  =  𝑋 )  →  𝑌  ∥  𝑋 ) ) | 
						
							| 26 | 25 | rexlimdvva | ⊢ ( ( 𝑅  ∈  Ring  ∧  ( 𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  →  ( ∃ 𝑦  ∈  𝐵 ∃ 𝑥  ∈  𝐵 ( ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 )  =  𝑍  ∧  ( 𝑥 ( .r ‘ 𝑅 ) 𝑍 )  =  𝑋 )  →  𝑌  ∥  𝑋 ) ) | 
						
							| 27 | 9 26 | biimtrrid | ⊢ ( ( 𝑅  ∈  Ring  ∧  ( 𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  →  ( ( ∃ 𝑦  ∈  𝐵 ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 )  =  𝑍  ∧  ∃ 𝑥  ∈  𝐵 ( 𝑥 ( .r ‘ 𝑅 ) 𝑍 )  =  𝑋 )  →  𝑌  ∥  𝑋 ) ) | 
						
							| 28 | 27 | expimpd | ⊢ ( 𝑅  ∈  Ring  →  ( ( ( 𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  ∧  ( ∃ 𝑦  ∈  𝐵 ( 𝑦 ( .r ‘ 𝑅 ) 𝑌 )  =  𝑍  ∧  ∃ 𝑥  ∈  𝐵 ( 𝑥 ( .r ‘ 𝑅 ) 𝑍 )  =  𝑋 ) )  →  𝑌  ∥  𝑋 ) ) | 
						
							| 29 | 8 28 | biimtrid | ⊢ ( 𝑅  ∈  Ring  →  ( ( 𝑌  ∥  𝑍  ∧  𝑍  ∥  𝑋 )  →  𝑌  ∥  𝑋 ) ) | 
						
							| 30 | 29 | 3impib | ⊢ ( ( 𝑅  ∈  Ring  ∧  𝑌  ∥  𝑍  ∧  𝑍  ∥  𝑋 )  →  𝑌  ∥  𝑋 ) |