A procedure for computing the symmetric difference of regions defined by polygonal curves

Given any two regions A, B in the plane, defined by polygonal (simple, closed and oriented) curves, associated with their respective boundaries, we describe a procedure to compute the symmetric difference A⊕B. The output is also presented in the form of polygonal curves, where in particular the curves describing the union A∪B, the intersection A∩B, the difference A\B, and the complement of the difference B\A, are also obtained. This is related with the two equivalent formulas to compute the symmetric difference, namely A⊕B = (A∪B)\(A∩B) = (A\B)∪(B\A).