Define completely constrained motion and successfully constrained motion.

1)Completely constrained motion :- When the motion between a pair is limited to a definite
direction irrespective of the direction of force applied, then the motion is said to be a completely
constrained motion.
2)Successfully constrained motion:- When the motion between the elements, forming a pair, is
such that the constrained motion is not completed by itself, but by some other means, then the
motion is said to be successfully constrained motion.