| Step | Hyp | Ref | Expression | 
						
							| 1 |  | axhil.1 |  |-  U = <. <. +h , .h >. , normh >. | 
						
							| 2 |  | axhil.2 |  |-  U e. CHilOLD | 
						
							| 3 |  | df-hba |  |-  ~H = ( BaseSet ` <. <. +h , .h >. , normh >. ) | 
						
							| 4 | 1 | fveq2i |  |-  ( BaseSet ` U ) = ( BaseSet ` <. <. +h , .h >. , normh >. ) | 
						
							| 5 | 3 4 | eqtr4i |  |-  ~H = ( BaseSet ` U ) | 
						
							| 6 | 2 | hlnvi |  |-  U e. NrmCVec | 
						
							| 7 | 1 6 | h2hva |  |-  +h = ( +v ` U ) | 
						
							| 8 | 1 6 | h2hsm |  |-  .h = ( .sOLD ` U ) | 
						
							| 9 | 5 7 8 | hldir |  |-  ( ( U e. CHilOLD /\ ( A e. CC /\ B e. CC /\ C e. ~H ) ) -> ( ( A + B ) .h C ) = ( ( A .h C ) +h ( B .h C ) ) ) | 
						
							| 10 | 2 9 | mpan |  |-  ( ( A e. CC /\ B e. CC /\ C e. ~H ) -> ( ( A + B ) .h C ) = ( ( A .h C ) +h ( B .h C ) ) ) |