| Step | Hyp | Ref | Expression | 
						
							| 1 |  | chpssat.1 |  |-  A e. CH | 
						
							| 2 |  | chpssat.2 |  |-  B e. CH | 
						
							| 3 | 1 2 | chpssati |  |-  ( A C. B -> E. x e. HAtoms ( x C_ B /\ -. x C_ A ) ) | 
						
							| 4 |  | ancom |  |-  ( ( x C_ B /\ -. x C_ A ) <-> ( -. x C_ A /\ x C_ B ) ) | 
						
							| 5 |  | pssss |  |-  ( A C. B -> A C_ B ) | 
						
							| 6 |  | atelch |  |-  ( x e. HAtoms -> x e. CH ) | 
						
							| 7 |  | chnle |  |-  ( ( A e. CH /\ x e. CH ) -> ( -. x C_ A <-> A C. ( A vH x ) ) ) | 
						
							| 8 | 1 7 | mpan |  |-  ( x e. CH -> ( -. x C_ A <-> A C. ( A vH x ) ) ) | 
						
							| 9 | 8 | adantl |  |-  ( ( A C_ B /\ x e. CH ) -> ( -. x C_ A <-> A C. ( A vH x ) ) ) | 
						
							| 10 |  | ibar |  |-  ( A C_ B -> ( x C_ B <-> ( A C_ B /\ x C_ B ) ) ) | 
						
							| 11 |  | chlub |  |-  ( ( A e. CH /\ x e. CH /\ B e. CH ) -> ( ( A C_ B /\ x C_ B ) <-> ( A vH x ) C_ B ) ) | 
						
							| 12 | 1 2 11 | mp3an13 |  |-  ( x e. CH -> ( ( A C_ B /\ x C_ B ) <-> ( A vH x ) C_ B ) ) | 
						
							| 13 | 10 12 | sylan9bb |  |-  ( ( A C_ B /\ x e. CH ) -> ( x C_ B <-> ( A vH x ) C_ B ) ) | 
						
							| 14 | 9 13 | anbi12d |  |-  ( ( A C_ B /\ x e. CH ) -> ( ( -. x C_ A /\ x C_ B ) <-> ( A C. ( A vH x ) /\ ( A vH x ) C_ B ) ) ) | 
						
							| 15 | 5 6 14 | syl2an |  |-  ( ( A C. B /\ x e. HAtoms ) -> ( ( -. x C_ A /\ x C_ B ) <-> ( A C. ( A vH x ) /\ ( A vH x ) C_ B ) ) ) | 
						
							| 16 | 4 15 | bitrid |  |-  ( ( A C. B /\ x e. HAtoms ) -> ( ( x C_ B /\ -. x C_ A ) <-> ( A C. ( A vH x ) /\ ( A vH x ) C_ B ) ) ) | 
						
							| 17 | 16 | rexbidva |  |-  ( A C. B -> ( E. x e. HAtoms ( x C_ B /\ -. x C_ A ) <-> E. x e. HAtoms ( A C. ( A vH x ) /\ ( A vH x ) C_ B ) ) ) | 
						
							| 18 | 3 17 | mpbid |  |-  ( A C. B -> E. x e. HAtoms ( A C. ( A vH x ) /\ ( A vH x ) C_ B ) ) |