arguments: m:matrix n:int >> matrix
Simplify the columns of the matrix 'm' in a way depending on the number 'n': if n=1, remove zero columns. if n=2, remove elements which are scalar multiples of others, and zeros, if n=3, remove columns which are divisible by other columns. Larger n will be possible as well: for example, one will be able to auto-reduce a set of columns, or remove monomial multiples, or replace with square-free elements.