| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							isoml.b | 
							⊢ 𝐵  =  ( Base ‘ 𝐾 )  | 
						
						
							| 2 | 
							
								
							 | 
							isoml.l | 
							⊢  ≤   =  ( le ‘ 𝐾 )  | 
						
						
							| 3 | 
							
								
							 | 
							isoml.j | 
							⊢  ∨   =  ( join ‘ 𝐾 )  | 
						
						
							| 4 | 
							
								
							 | 
							isoml.m | 
							⊢  ∧   =  ( meet ‘ 𝐾 )  | 
						
						
							| 5 | 
							
								
							 | 
							isoml.o | 
							⊢  ⊥   =  ( oc ‘ 𝐾 )  | 
						
						
							| 6 | 
							
								
							 | 
							fveq2 | 
							⊢ ( 𝑘  =  𝐾  →  ( Base ‘ 𝑘 )  =  ( Base ‘ 𝐾 ) )  | 
						
						
							| 7 | 
							
								6 1
							 | 
							eqtr4di | 
							⊢ ( 𝑘  =  𝐾  →  ( Base ‘ 𝑘 )  =  𝐵 )  | 
						
						
							| 8 | 
							
								
							 | 
							fveq2 | 
							⊢ ( 𝑘  =  𝐾  →  ( le ‘ 𝑘 )  =  ( le ‘ 𝐾 ) )  | 
						
						
							| 9 | 
							
								8 2
							 | 
							eqtr4di | 
							⊢ ( 𝑘  =  𝐾  →  ( le ‘ 𝑘 )  =   ≤  )  | 
						
						
							| 10 | 
							
								9
							 | 
							breqd | 
							⊢ ( 𝑘  =  𝐾  →  ( 𝑥 ( le ‘ 𝑘 ) 𝑦  ↔  𝑥  ≤  𝑦 ) )  | 
						
						
							| 11 | 
							
								
							 | 
							fveq2 | 
							⊢ ( 𝑘  =  𝐾  →  ( join ‘ 𝑘 )  =  ( join ‘ 𝐾 ) )  | 
						
						
							| 12 | 
							
								11 3
							 | 
							eqtr4di | 
							⊢ ( 𝑘  =  𝐾  →  ( join ‘ 𝑘 )  =   ∨  )  | 
						
						
							| 13 | 
							
								
							 | 
							eqidd | 
							⊢ ( 𝑘  =  𝐾  →  𝑥  =  𝑥 )  | 
						
						
							| 14 | 
							
								
							 | 
							fveq2 | 
							⊢ ( 𝑘  =  𝐾  →  ( meet ‘ 𝑘 )  =  ( meet ‘ 𝐾 ) )  | 
						
						
							| 15 | 
							
								14 4
							 | 
							eqtr4di | 
							⊢ ( 𝑘  =  𝐾  →  ( meet ‘ 𝑘 )  =   ∧  )  | 
						
						
							| 16 | 
							
								
							 | 
							eqidd | 
							⊢ ( 𝑘  =  𝐾  →  𝑦  =  𝑦 )  | 
						
						
							| 17 | 
							
								
							 | 
							fveq2 | 
							⊢ ( 𝑘  =  𝐾  →  ( oc ‘ 𝑘 )  =  ( oc ‘ 𝐾 ) )  | 
						
						
							| 18 | 
							
								17 5
							 | 
							eqtr4di | 
							⊢ ( 𝑘  =  𝐾  →  ( oc ‘ 𝑘 )  =   ⊥  )  | 
						
						
							| 19 | 
							
								18
							 | 
							fveq1d | 
							⊢ ( 𝑘  =  𝐾  →  ( ( oc ‘ 𝑘 ) ‘ 𝑥 )  =  (  ⊥  ‘ 𝑥 ) )  | 
						
						
							| 20 | 
							
								15 16 19
							 | 
							oveq123d | 
							⊢ ( 𝑘  =  𝐾  →  ( 𝑦 ( meet ‘ 𝑘 ) ( ( oc ‘ 𝑘 ) ‘ 𝑥 ) )  =  ( 𝑦  ∧  (  ⊥  ‘ 𝑥 ) ) )  | 
						
						
							| 21 | 
							
								12 13 20
							 | 
							oveq123d | 
							⊢ ( 𝑘  =  𝐾  →  ( 𝑥 ( join ‘ 𝑘 ) ( 𝑦 ( meet ‘ 𝑘 ) ( ( oc ‘ 𝑘 ) ‘ 𝑥 ) ) )  =  ( 𝑥  ∨  ( 𝑦  ∧  (  ⊥  ‘ 𝑥 ) ) ) )  | 
						
						
							| 22 | 
							
								21
							 | 
							eqeq2d | 
							⊢ ( 𝑘  =  𝐾  →  ( 𝑦  =  ( 𝑥 ( join ‘ 𝑘 ) ( 𝑦 ( meet ‘ 𝑘 ) ( ( oc ‘ 𝑘 ) ‘ 𝑥 ) ) )  ↔  𝑦  =  ( 𝑥  ∨  ( 𝑦  ∧  (  ⊥  ‘ 𝑥 ) ) ) ) )  | 
						
						
							| 23 | 
							
								10 22
							 | 
							imbi12d | 
							⊢ ( 𝑘  =  𝐾  →  ( ( 𝑥 ( le ‘ 𝑘 ) 𝑦  →  𝑦  =  ( 𝑥 ( join ‘ 𝑘 ) ( 𝑦 ( meet ‘ 𝑘 ) ( ( oc ‘ 𝑘 ) ‘ 𝑥 ) ) ) )  ↔  ( 𝑥  ≤  𝑦  →  𝑦  =  ( 𝑥  ∨  ( 𝑦  ∧  (  ⊥  ‘ 𝑥 ) ) ) ) ) )  | 
						
						
							| 24 | 
							
								7 23
							 | 
							raleqbidv | 
							⊢ ( 𝑘  =  𝐾  →  ( ∀ 𝑦  ∈  ( Base ‘ 𝑘 ) ( 𝑥 ( le ‘ 𝑘 ) 𝑦  →  𝑦  =  ( 𝑥 ( join ‘ 𝑘 ) ( 𝑦 ( meet ‘ 𝑘 ) ( ( oc ‘ 𝑘 ) ‘ 𝑥 ) ) ) )  ↔  ∀ 𝑦  ∈  𝐵 ( 𝑥  ≤  𝑦  →  𝑦  =  ( 𝑥  ∨  ( 𝑦  ∧  (  ⊥  ‘ 𝑥 ) ) ) ) ) )  | 
						
						
							| 25 | 
							
								7 24
							 | 
							raleqbidv | 
							⊢ ( 𝑘  =  𝐾  →  ( ∀ 𝑥  ∈  ( Base ‘ 𝑘 ) ∀ 𝑦  ∈  ( Base ‘ 𝑘 ) ( 𝑥 ( le ‘ 𝑘 ) 𝑦  →  𝑦  =  ( 𝑥 ( join ‘ 𝑘 ) ( 𝑦 ( meet ‘ 𝑘 ) ( ( oc ‘ 𝑘 ) ‘ 𝑥 ) ) ) )  ↔  ∀ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐵 ( 𝑥  ≤  𝑦  →  𝑦  =  ( 𝑥  ∨  ( 𝑦  ∧  (  ⊥  ‘ 𝑥 ) ) ) ) ) )  | 
						
						
							| 26 | 
							
								
							 | 
							df-oml | 
							⊢ OML  =  { 𝑘  ∈  OL  ∣  ∀ 𝑥  ∈  ( Base ‘ 𝑘 ) ∀ 𝑦  ∈  ( Base ‘ 𝑘 ) ( 𝑥 ( le ‘ 𝑘 ) 𝑦  →  𝑦  =  ( 𝑥 ( join ‘ 𝑘 ) ( 𝑦 ( meet ‘ 𝑘 ) ( ( oc ‘ 𝑘 ) ‘ 𝑥 ) ) ) ) }  | 
						
						
							| 27 | 
							
								25 26
							 | 
							elrab2 | 
							⊢ ( 𝐾  ∈  OML  ↔  ( 𝐾  ∈  OL  ∧  ∀ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐵 ( 𝑥  ≤  𝑦  →  𝑦  =  ( 𝑥  ∨  ( 𝑦  ∧  (  ⊥  ‘ 𝑥 ) ) ) ) ) )  |