Expression 8: "x" equals "a" plus 3 "d" left brace, 0 less than or equal to "y" less than or equal to "f" left parenthesis, "a" plus 3 "d" plus "n" times "d" , right parenthesis , right bracex=a+3d0≤y≤fa+3d+n·d
8
Expression 9: "x" equals "b" left brace, 0 less than or equal to "y" less than or equal to "f" left parenthesis, "b" , right parenthesis , right bracex=b0≤y≤fb
9
Expression 10: 0 less than or equal to "y" less than or equal to "f" left parenthesis, "a" plus "n" times "d" , right parenthesis left brace, "a" less than or equal to "x" less than or equal to "a" plus "d" , right brace0≤y≤fa+n·da≤x≤a+d
10
Expression 11: 0 less than or equal to "y" less than or equal to "f" left parenthesis, "a" plus "d" plus "n" times "d" , right parenthesis left brace, "a" plus "d" less than or equal to "x" less than or equal to "a" plus 2 "d" , right brace0≤y≤fa+d+n·da+d≤x≤a+2d
11
Expression 12: 0 less than or equal to "y" less than or equal to "f" left parenthesis, "a" plus 2 "d" plus "n" times "d" , right parenthesis left brace, "a" plus 2 "d" less than or equal to "x" less than or equal to "a" plus 3 "d" , right brace0≤y≤fa+2d+n·da+2d≤x≤a+3d
12
Expression 13: 0 less than or equal to "y" less than or equal to "f" left parenthesis, "a" plus 3 "d" plus "n" times "d" , right parenthesis left brace, "a" plus 3 "d" less than or equal to "x" less than or equal to "b" , right brace0≤y≤fa+3d+n·da+3d≤x≤b