| Step | Hyp | Ref | Expression | 
						
							| 1 |  | chpssat.1 |  |-  A e. CH | 
						
							| 2 |  | chpssat.2 |  |-  B e. CH | 
						
							| 3 |  | dfpss3 |  |-  ( A C. B <-> ( A C_ B /\ -. B C_ A ) ) | 
						
							| 4 | 3 | simprbi |  |-  ( A C. B -> -. B C_ A ) | 
						
							| 5 |  | iman |  |-  ( ( x C_ B -> x C_ A ) <-> -. ( x C_ B /\ -. x C_ A ) ) | 
						
							| 6 | 5 | ralbii |  |-  ( A. x e. HAtoms ( x C_ B -> x C_ A ) <-> A. x e. HAtoms -. ( x C_ B /\ -. x C_ A ) ) | 
						
							| 7 |  | ss2rab |  |-  ( { x e. HAtoms | x C_ B } C_ { x e. HAtoms | x C_ A } <-> A. x e. HAtoms ( x C_ B -> x C_ A ) ) | 
						
							| 8 |  | ssrab2 |  |-  { x e. HAtoms | x C_ B } C_ HAtoms | 
						
							| 9 |  | atssch |  |-  HAtoms C_ CH | 
						
							| 10 | 8 9 | sstri |  |-  { x e. HAtoms | x C_ B } C_ CH | 
						
							| 11 |  | ssrab2 |  |-  { x e. HAtoms | x C_ A } C_ HAtoms | 
						
							| 12 | 11 9 | sstri |  |-  { x e. HAtoms | x C_ A } C_ CH | 
						
							| 13 |  | chsupss |  |-  ( ( { x e. HAtoms | x C_ B } C_ CH /\ { x e. HAtoms | x C_ A } C_ CH ) -> ( { x e. HAtoms | x C_ B } C_ { x e. HAtoms | x C_ A } -> ( \/H ` { x e. HAtoms | x C_ B } ) C_ ( \/H ` { x e. HAtoms | x C_ A } ) ) ) | 
						
							| 14 | 10 12 13 | mp2an |  |-  ( { x e. HAtoms | x C_ B } C_ { x e. HAtoms | x C_ A } -> ( \/H ` { x e. HAtoms | x C_ B } ) C_ ( \/H ` { x e. HAtoms | x C_ A } ) ) | 
						
							| 15 | 2 | hatomistici |  |-  B = ( \/H ` { x e. HAtoms | x C_ B } ) | 
						
							| 16 | 1 | hatomistici |  |-  A = ( \/H ` { x e. HAtoms | x C_ A } ) | 
						
							| 17 | 14 15 16 | 3sstr4g |  |-  ( { x e. HAtoms | x C_ B } C_ { x e. HAtoms | x C_ A } -> B C_ A ) | 
						
							| 18 | 7 17 | sylbir |  |-  ( A. x e. HAtoms ( x C_ B -> x C_ A ) -> B C_ A ) | 
						
							| 19 | 6 18 | sylbir |  |-  ( A. x e. HAtoms -. ( x C_ B /\ -. x C_ A ) -> B C_ A ) | 
						
							| 20 | 19 | con3i |  |-  ( -. B C_ A -> -. A. x e. HAtoms -. ( x C_ B /\ -. x C_ A ) ) | 
						
							| 21 |  | dfrex2 |  |-  ( E. x e. HAtoms ( x C_ B /\ -. x C_ A ) <-> -. A. x e. HAtoms -. ( x C_ B /\ -. x C_ A ) ) | 
						
							| 22 | 20 21 | sylibr |  |-  ( -. B C_ A -> E. x e. HAtoms ( x C_ B /\ -. x C_ A ) ) | 
						
							| 23 | 4 22 | syl |  |-  ( A C. B -> E. x e. HAtoms ( x C_ B /\ -. x C_ A ) ) |