This quantity corresponds to hue rather than saturation or brightness in a visualization method called domain coloring. A result named for this quantity is invoked to compute a function nt (“n-sub-t”), which is both continuous and integer-valued and thus constant, in a standard proof of Rouche’s theorem. A formula named for this quantity sets the contour integral of “f prime over f” proportional to the number of zeros (-5[1])minus the number of poles of f within a region. This quantity is restricted to an interval when defining the (*) complex logarithm to avoid non-uniqueness. (-5[1])As a curve is traced, (10[1]-5[1])a jump in this quantity (10[1])by its usual upper bound yields an increase of one in the winding number. This quantity is denoted phi in the expression “z equals r times e to the i phi.” For 10 points, name this quantity that, along with the magnitude, parametrizes a complex number. ■END■ (10[3])