| Step | Hyp | Ref | Expression | 
						
							| 1 |  | phlsrng.f |  |-  F = ( Scalar ` W ) | 
						
							| 2 |  | phllmhm.h |  |-  ., = ( .i ` W ) | 
						
							| 3 |  | phllmhm.v |  |-  V = ( Base ` W ) | 
						
							| 4 |  | ipdir.g |  |-  .+ = ( +g ` W ) | 
						
							| 5 |  | ipdir.p |  |-  .+^ = ( +g ` F ) | 
						
							| 6 |  | eqid |  |-  ( x e. V |-> ( x ., C ) ) = ( x e. V |-> ( x ., C ) ) | 
						
							| 7 | 1 2 3 6 | phllmhm |  |-  ( ( W e. PreHil /\ C e. V ) -> ( x e. V |-> ( x ., C ) ) e. ( W LMHom ( ringLMod ` F ) ) ) | 
						
							| 8 | 7 | 3ad2antr3 |  |-  ( ( W e. PreHil /\ ( A e. V /\ B e. V /\ C e. V ) ) -> ( x e. V |-> ( x ., C ) ) e. ( W LMHom ( ringLMod ` F ) ) ) | 
						
							| 9 |  | lmghm |  |-  ( ( x e. V |-> ( x ., C ) ) e. ( W LMHom ( ringLMod ` F ) ) -> ( x e. V |-> ( x ., C ) ) e. ( W GrpHom ( ringLMod ` F ) ) ) | 
						
							| 10 | 8 9 | syl |  |-  ( ( W e. PreHil /\ ( A e. V /\ B e. V /\ C e. V ) ) -> ( x e. V |-> ( x ., C ) ) e. ( W GrpHom ( ringLMod ` F ) ) ) | 
						
							| 11 |  | simpr1 |  |-  ( ( W e. PreHil /\ ( A e. V /\ B e. V /\ C e. V ) ) -> A e. V ) | 
						
							| 12 |  | simpr2 |  |-  ( ( W e. PreHil /\ ( A e. V /\ B e. V /\ C e. V ) ) -> B e. V ) | 
						
							| 13 |  | rlmplusg |  |-  ( +g ` F ) = ( +g ` ( ringLMod ` F ) ) | 
						
							| 14 | 5 13 | eqtri |  |-  .+^ = ( +g ` ( ringLMod ` F ) ) | 
						
							| 15 | 3 4 14 | ghmlin |  |-  ( ( ( x e. V |-> ( x ., C ) ) e. ( W GrpHom ( ringLMod ` F ) ) /\ A e. V /\ B e. V ) -> ( ( x e. V |-> ( x ., C ) ) ` ( A .+ B ) ) = ( ( ( x e. V |-> ( x ., C ) ) ` A ) .+^ ( ( x e. V |-> ( x ., C ) ) ` B ) ) ) | 
						
							| 16 | 10 11 12 15 | syl3anc |  |-  ( ( W e. PreHil /\ ( A e. V /\ B e. V /\ C e. V ) ) -> ( ( x e. V |-> ( x ., C ) ) ` ( A .+ B ) ) = ( ( ( x e. V |-> ( x ., C ) ) ` A ) .+^ ( ( x e. V |-> ( x ., C ) ) ` B ) ) ) | 
						
							| 17 |  | phllmod |  |-  ( W e. PreHil -> W e. LMod ) | 
						
							| 18 | 3 4 | lmodvacl |  |-  ( ( W e. LMod /\ A e. V /\ B e. V ) -> ( A .+ B ) e. V ) | 
						
							| 19 | 17 18 | syl3an1 |  |-  ( ( W e. PreHil /\ A e. V /\ B e. V ) -> ( A .+ B ) e. V ) | 
						
							| 20 | 19 | 3adant3r3 |  |-  ( ( W e. PreHil /\ ( A e. V /\ B e. V /\ C e. V ) ) -> ( A .+ B ) e. V ) | 
						
							| 21 |  | oveq1 |  |-  ( x = ( A .+ B ) -> ( x ., C ) = ( ( A .+ B ) ., C ) ) | 
						
							| 22 |  | ovex |  |-  ( x ., C ) e. _V | 
						
							| 23 | 21 6 22 | fvmpt3i |  |-  ( ( A .+ B ) e. V -> ( ( x e. V |-> ( x ., C ) ) ` ( A .+ B ) ) = ( ( A .+ B ) ., C ) ) | 
						
							| 24 | 20 23 | syl |  |-  ( ( W e. PreHil /\ ( A e. V /\ B e. V /\ C e. V ) ) -> ( ( x e. V |-> ( x ., C ) ) ` ( A .+ B ) ) = ( ( A .+ B ) ., C ) ) | 
						
							| 25 |  | oveq1 |  |-  ( x = A -> ( x ., C ) = ( A ., C ) ) | 
						
							| 26 | 25 6 22 | fvmpt3i |  |-  ( A e. V -> ( ( x e. V |-> ( x ., C ) ) ` A ) = ( A ., C ) ) | 
						
							| 27 | 11 26 | syl |  |-  ( ( W e. PreHil /\ ( A e. V /\ B e. V /\ C e. V ) ) -> ( ( x e. V |-> ( x ., C ) ) ` A ) = ( A ., C ) ) | 
						
							| 28 |  | oveq1 |  |-  ( x = B -> ( x ., C ) = ( B ., C ) ) | 
						
							| 29 | 28 6 22 | fvmpt3i |  |-  ( B e. V -> ( ( x e. V |-> ( x ., C ) ) ` B ) = ( B ., C ) ) | 
						
							| 30 | 12 29 | syl |  |-  ( ( W e. PreHil /\ ( A e. V /\ B e. V /\ C e. V ) ) -> ( ( x e. V |-> ( x ., C ) ) ` B ) = ( B ., C ) ) | 
						
							| 31 | 27 30 | oveq12d |  |-  ( ( W e. PreHil /\ ( A e. V /\ B e. V /\ C e. V ) ) -> ( ( ( x e. V |-> ( x ., C ) ) ` A ) .+^ ( ( x e. V |-> ( x ., C ) ) ` B ) ) = ( ( A ., C ) .+^ ( B ., C ) ) ) | 
						
							| 32 | 16 24 31 | 3eqtr3d |  |-  ( ( W e. PreHil /\ ( A e. V /\ B e. V /\ C e. V ) ) -> ( ( A .+ B ) ., C ) = ( ( A ., C ) .+^ ( B ., C ) ) ) |