nL-n-Luc3 nL-Sum of Vectors Point

Morley brought up this technique: vectors can be made up from a fixed origin (nL-n-P3) to the (n-1)L-versions of another point. The endpoint of the sum of these vectors will be a new central nL-point. This method is used for nL-n-P7.
The construction is sometimes abbreviated as SVP.

Application in a 4-Line:

• There is a QL-point X on the line QL-L4 for which the Sum Vector of X.H1, X.H2, X.H3, X.H4 is QL-P3. It is the point QL-P2.QL-P3 (-1 : 4), as well as QL-P12.QL-P27 (-3:4).
(H1, H2, H3, H4 being the orthocenters of the 4 Component Triangles of the QL)
See Ref-34, QFG#850.