I am currently doing some research in Clifford Algebra. My topic is to find explicit representation of its basis through matrices with entries in clifford algebra itself. At this moment I am trying to write code in mathematica to do KroneckerProduct and Quaternion multiplication. Now I have encounter a coding problem about mathematica. In the package of << Algebra`Quaternions`, quaternion multiplication is defined with ** instead of *, where in matrix multiplication product of entries are defined with *. Thus when I use quaternion entries in my matrix multiplication, its matrix product will give me, say, Quaternion[0,1,0,0]Quaternion[0,0,1,0] instead of Quaternion[0,0,0,1] where Quaternion[a,b,c,d] = a + b i + c j + d k. Does any one have any idea to override this function. Thank you.