template<typename Type>
Type***& LinAlg::Matrix<Type>::operator ()(unsigned* row_interval, unsigned* column_interval)const
{
    //Assuma as devidas inicializações.
    Type*** ret

    if(row_interval[0] < row_interval[1]){
        if(column_interval[0] < column_interval[1]){
            for(unsigned i = row_interval[0]; i <= row_interval[1]; ++i)
                for(unsigned j = column_interval[0]; j <= column_interval[1]; ++j)
                    ret[i - row_interval[0]][j - column_interval[0]] = &this->mat[i-1][j-1];

        }else{
            for(unsigned i = row_interval[0]; i <= row_interval[1]; ++i)
                for(unsigned j = column_interval[0]; j >= column_interval[1]; --j)
                    ret[i - row_interval[0]][column_interval[0] - j] = &this->mat[i-1][j - 1];
        }

    } else{
        if(column_interval[0] < column_interval[1]){
            for(unsigned i = row_interval[0]; i >= row_interval[1]; --i)
                for(unsigned j = column_interval[0]; j <= column_interval[1]; ++j)
                    ret[row_interval[0] - i][j - column_interval[0]] = &this->mat[i-1][j-1];
        }else{
            for(unsigned i = row_interval[0]; i >= row_interval[1]; --i)
                for(unsigned j = column_interval[0]; j >= column_interval[1]; --j)
                    ret[row_interval[0] - i][column_interval[0] - j] = &this->mat[i-1][j - 1];
        }
    }

    return ret;
}