Maxima Function
zerofor (M)
zerofor(M,fld)
Return a zero matrix that has the same shape as the matrix M. Every entry of the zero matrix is the additive identity of the field fld; the default for fld is generalring.
The first argument M should be a square matrix or a non-matrix. When M is a matrix, each entry of M can be a square matrix -- thus M can be a blocked Maxima matrix. The matrix can be blocked to any (finite) depth.