public class MathMatrix $\{$

$//$ instance variable

$/**$

$*$ create a MathMatrix with cells equal to the values in mat.

$*$ A "deep" copy of mat is made.

$*$ Changes to mat after this constructor do not affect this

$*$ Matrix and changes to this MathMatrix do not affect mat

$*$ @param mat mat $!=$null, mat.length $>0,$ mat$[0].$length $>0,$

$*$ mat is a rectangular matrix

$*/$

public MathMatrix$($int$[][]$ mat$)\{$

$\}$