sentences:  In Figure 6 the inclination degree of layer lines gradually changes according to the following sequence of degrees (+30, –30, +30, –30, +30).Layer periods "p"b and "p"r represent the distances between the curves along the vertical axis.The presented formulas for computing the period "p"m (the vertical distance between the moiré curves) and the optical speedup (along the vertical axis) are valid for Figure 6.