The statement 'All squares are rectangles' can be written as:
forallx(Square(x)landRectangle(x))\\forall x (Square(x) \\land Rectangle(x))forallx(Square(x)landRectangle(x))
forallx(Square(x)rightarrowRectangle(x))\\forall x (Square(x) \\rightarrow Rectangle(x))forallx(Square(x)rightarrowRectangle(x))
existsx(Square(x)rightarrowRectangle(x))\\exists x (Square(x) \\rightarrow Rectangle(x))existsx(Square(x)rightarrowRectangle(x))
forallx(Rectangle(x)rightarrowSquare(x))\\forall x (Rectangle(x) \\rightarrow Square(x))forallx(Rectangle(x)rightarrowSquare(x))