module x_detector (
input [1:0] a,
output eq_logic,
output eq_case
);
assign eq_logic = (a == 2'bx1); // Logical equality: if any bit is x/z, result = x.
assign eq_case = (a === 2'bx1); // Case equality: compares all 4 states literally (0,1,x,z).
endmodule