Figure A7.

The fold angle κ, i.e., angle between parent segment and the half-plane determined by the two daughter segments, is in this spatial non-recurrent bifurcation equal to π − θ. The azimuth angle φ is taken from the bisector to the projection of the parent segment in the plane of the daughter segments. The gray area of the plane formed by the daughter segments (daughters’ plane) and the line perpendicular to the daughters’ bisector (i.e., the Y-axis) is called the daughters’ half-plane.