Expression 1: 0 less than or equal to mod left parenthesis, floor left parenthesis, StartFraction, floor left parenthesis, "x" , right parenthesis Over 2 Superscript, floor left parenthesis, "y" , right parenthesis , Baseline , EndFraction , right parenthesis , 2 , right parenthesis0≤modfloorfloorx2floory,2