Expression 1: "x" times signum left parenthesis, "y" , right parenthesis less than "y" times signum left parenthesis, "x" , right parenthesis left brace, negative 1 less than "x" less than 1 , right brace left brace, negative 1 less than "y" less than 1 , right bracex·signy<y·signx−1<x<1−1<y<1