| Step | Hyp | Ref | Expression | 
						
							| 1 |  | choccl |  |-  ( A e. CH -> ( _|_ ` A ) e. CH ) | 
						
							| 2 | 1 | adantl |  |-  ( ( S e. CHStates /\ A e. CH ) -> ( _|_ ` A ) e. CH ) | 
						
							| 3 |  | chsh |  |-  ( A e. CH -> A e. SH ) | 
						
							| 4 |  | shococss |  |-  ( A e. SH -> A C_ ( _|_ ` ( _|_ ` A ) ) ) | 
						
							| 5 | 3 4 | syl |  |-  ( A e. CH -> A C_ ( _|_ ` ( _|_ ` A ) ) ) | 
						
							| 6 | 5 | adantl |  |-  ( ( S e. CHStates /\ A e. CH ) -> A C_ ( _|_ ` ( _|_ ` A ) ) ) | 
						
							| 7 | 2 6 | jca |  |-  ( ( S e. CHStates /\ A e. CH ) -> ( ( _|_ ` A ) e. CH /\ A C_ ( _|_ ` ( _|_ ` A ) ) ) ) | 
						
							| 8 |  | hstosum |  |-  ( ( ( S e. CHStates /\ A e. CH ) /\ ( ( _|_ ` A ) e. CH /\ A C_ ( _|_ ` ( _|_ ` A ) ) ) ) -> ( S ` ( A vH ( _|_ ` A ) ) ) = ( ( S ` A ) +h ( S ` ( _|_ ` A ) ) ) ) | 
						
							| 9 | 7 8 | mpdan |  |-  ( ( S e. CHStates /\ A e. CH ) -> ( S ` ( A vH ( _|_ ` A ) ) ) = ( ( S ` A ) +h ( S ` ( _|_ ` A ) ) ) ) | 
						
							| 10 |  | chjo |  |-  ( A e. CH -> ( A vH ( _|_ ` A ) ) = ~H ) | 
						
							| 11 | 10 | fveq2d |  |-  ( A e. CH -> ( S ` ( A vH ( _|_ ` A ) ) ) = ( S ` ~H ) ) | 
						
							| 12 | 11 | adantl |  |-  ( ( S e. CHStates /\ A e. CH ) -> ( S ` ( A vH ( _|_ ` A ) ) ) = ( S ` ~H ) ) | 
						
							| 13 | 9 12 | eqtr3d |  |-  ( ( S e. CHStates /\ A e. CH ) -> ( ( S ` A ) +h ( S ` ( _|_ ` A ) ) ) = ( S ` ~H ) ) |