Boolean Expression for Signed Magnitude Comparator

Hello, I need boolean expression for 4 bit signed magnitude comparator say num 1 is A = SA A2 A1 A0 and num 2 is B= SB B2 B1 B0 where S represents signed bit..just to give you an idea of what i am talking about.. heres the boolean expression for A==B = (SA(XNOR)SB) (A2(XNOR)B2) (A3(XNOR)B3) (A4(XNOR)B4) However i am unable to figureout the expression for A>B and A<B so i need that shouldnt take you more then 10 minutes to write if you have taken Digital Logic/Computer Logic Course. I need it urgently. Thanks!