abo-elleef

class Matrix
  def &(matrix)
    Matrix.Raise ErrDimensionMismatch, "Matrix dimension mismatch" unless (row_count == matrix.row_count && column_count == matrix.column_count)
    rows = Array.new(row_count) {|i|
      Array.new(column_count) {|j|
        self[i, j] & matrix[i, j]
      }
    }
    new_matrix rows, matrix.column_count
  end