Gabriel,

This extends my previous response, in that because the MMult function returns a
matrix (even if it's a 1 x 1 matrix), the sqr function cannot be used. The
appropriate formula you want to use is to incorporate the SUMPRODUCT function,
which when applied to two arrays results
in a scalar (rather than a 1 x 1 matrix), for which the sqr function can be
applied.

-- Dennis Eisen