Function: identfor (<M>)
Function: identfor (<M>, <fld>) Return an identity matrix that has the same shape as the matrix <M>. The diagonal entries of the identity matrix are the multiplicative 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.
(%o1) true (%i2)