| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							atelch | 
							⊢ ( 𝐵  ∈  HAtoms  →  𝐵  ∈   Cℋ  )  | 
						
						
							| 2 | 
							
								
							 | 
							chincl | 
							⊢ ( ( 𝐴  ∈   Cℋ   ∧  𝐵  ∈   Cℋ  )  →  ( 𝐴  ∩  𝐵 )  ∈   Cℋ  )  | 
						
						
							| 3 | 
							
								1 2
							 | 
							sylan2 | 
							⊢ ( ( 𝐴  ∈   Cℋ   ∧  𝐵  ∈  HAtoms )  →  ( 𝐴  ∩  𝐵 )  ∈   Cℋ  )  | 
						
						
							| 4 | 
							
								
							 | 
							atcveq0 | 
							⊢ ( ( ( 𝐴  ∩  𝐵 )  ∈   Cℋ   ∧  𝐵  ∈  HAtoms )  →  ( ( 𝐴  ∩  𝐵 )  ⋖ℋ  𝐵  ↔  ( 𝐴  ∩  𝐵 )  =  0ℋ ) )  | 
						
						
							| 5 | 
							
								3 4
							 | 
							sylancom | 
							⊢ ( ( 𝐴  ∈   Cℋ   ∧  𝐵  ∈  HAtoms )  →  ( ( 𝐴  ∩  𝐵 )  ⋖ℋ  𝐵  ↔  ( 𝐴  ∩  𝐵 )  =  0ℋ ) )  | 
						
						
							| 6 | 
							
								
							 | 
							cvexch | 
							⊢ ( ( 𝐴  ∈   Cℋ   ∧  𝐵  ∈   Cℋ  )  →  ( ( 𝐴  ∩  𝐵 )  ⋖ℋ  𝐵  ↔  𝐴  ⋖ℋ  ( 𝐴  ∨ℋ  𝐵 ) ) )  | 
						
						
							| 7 | 
							
								1 6
							 | 
							sylan2 | 
							⊢ ( ( 𝐴  ∈   Cℋ   ∧  𝐵  ∈  HAtoms )  →  ( ( 𝐴  ∩  𝐵 )  ⋖ℋ  𝐵  ↔  𝐴  ⋖ℋ  ( 𝐴  ∨ℋ  𝐵 ) ) )  | 
						
						
							| 8 | 
							
								5 7
							 | 
							bitr3d | 
							⊢ ( ( 𝐴  ∈   Cℋ   ∧  𝐵  ∈  HAtoms )  →  ( ( 𝐴  ∩  𝐵 )  =  0ℋ  ↔  𝐴  ⋖ℋ  ( 𝐴  ∨ℋ  𝐵 ) ) )  |