Expression 6: "g" left parenthesis, "P" , right parenthesis equals left brace, 0 less than or equal to "P" . "x" less than or equal to "n" minus 1 : 1 , 0 , right brace left brace, 0 less than or equal to "P" . "y" less than or equal to "n" minus 1 : 1 , 0 , right brace left brace, "P" . "x" plus "P" . "y" less than or equal to "n" minus 1 : 1 , 0 , right bracegP=0≤P.x≤n−1:1,00≤P.y≤n−1:1,0P.x+P.y≤n−1:1,0