Constraints either are relations between geometrical objects, which determine a
geometrical condition of position, or between a dimensional object and
geometrical objects, which determine a dimensional condition among the
geometrical objects. No geometrical object is superior to another one, they
are all equal.
In this section you will find the description of the constraints used in
SISCAD-P.
Due to the constraints geometrical objects are restricted in their ability to be
manipulated. For example: two finite lines have the relation to be parallel, so
that they will remain parallel even after any later manipulation. Their
distance or position to each other, however, can change.
In contrast to constructional relations constraints do not determine the
objects ambiguously.
A measure for an object's ability to be manipulated is the degree
of freedom what is described later.