Expression 3: "y" less than or equal to StartRoot, 1 minus "x" squared , EndRoot left brace, 0 less than or equal to "y" , right bracey≤1−x20≤y
3
Expression 4: polygon left parenthesis, left parenthesis, 1 , 0 , right parenthesis , left parenthesis, negative 1 , 0 , right parenthesis , left parenthesis, cos left parenthesis, "L" , right parenthesis , sin left parenthesis, "L" , right parenthesis , right parenthesis , right parenthesispolygon1,0,−1,0,cosL,sinL