let "z" be the origin in "n"-dimensional complex space, c. that is, "z" is the point where the "n" coordinate functions formula_17 simultaneously vanish. let p be ("n" - 1)-dimensional complex projective space with homogeneous coordinates formula_18. let formula_19 be the subset of c × p that satisfies simultaneously the equations formula_20 for "i, j" = 1, ..., "n". the projection