Expression 3: "d" Subscript, "o" "t" , Baseline left parenthesis, "u" , "v" , right parenthesis equals "u" . "x" "v" . "x" plus "u" . "y" "v" . "y"dotu,v=u.xv.x+u.yv.y
3
Expression 4: "a" Subscript, "b" "s" , Baseline left parenthesis, left parenthesis, "x" plus 1 , "y" , right parenthesis , right parenthesis less than or equal to 2 "a" Subscript, "b" "s" , Baseline left parenthesis, left parenthesis, "x" minus 1 , "y" , right parenthesis , right parenthesisabsx+1,y≤2absx−1,y