What's event region of @ in System Verilog?

In reply to dave_59:

HI Dave In LRM there are arrows that re-enter the active region after the Active,Inactive,NBA regions so I tried the code below:

reg A = 0;

//Method 1
always @ ( A )
#10 A = ~A;

// Method 2
always @ ( A )
#10 A <= ~A;

Why is it that method1 doesn’t give an infinite loop whereas method2 gives an infinite loop
Also could u explain what the re-entrant arrows actualy Indicate?

Thank You In Advance