Non-blocking assignment

module top();
reg A1,A2,B1,B2;

initial begin //Non-blocking assignment
A1=1;
B1=0;
A1<=B1;
B1<=A1;
end

initial begin //Blocking assignment
A2=1;
B2=0;
A2=B2;
B2=A2;
end

initial begin
$monitor("A1=%b B1=%b A2=%b B2=%b",A1,B1,A2,B2);
end

endmodule