Group exclusive-or.
c=setxor(a,b)
[c,i]=setxor(a,b)
SETXOR returns the IMAT_GROUP entities that are not in the intersection of IMAT_GROUP A and IMAT_GROUP B. Both A and B must be scalar IMAT_GROUP objects. The result will be sorted.
IA and IB are indices such that C is a sorted combination of A(IA) and B(IB).