Point C is located slightly to the left of point B.
along line AC.
Note how step 5 creates triangle CYX, a small approximately equilateral triangle that protrudes past the bottom edge. For step 6, unfold.
Raise the back layer of paper, reversing step 2.
Use a fingertip to slowly curve point Z toward the centerline. Curve only until the crease lines made in step 5 form valley folds; do not press point Z flat against the centerline.