MINOR _ _ _ _ _ _ _ _ _ _ _ _ operator
<matrix> :- a matrix. <r>,<c> :- positive integers.
minorcomputes the (<r>,<c>)'th minor of <matrix>. This is created by removing the <r>'th row and the <c>'th column from <matrix>.
minor(A,1,3); [4 5] [ ] [7 8]
Related functions: remove_columns, remove_rows.