In reply to kansagaratushar:
constraint no_erase { (cmd == write) -> foreach (add[i]) !(add[i] inside {list});}
function void post_randomize();
case(cmd)
write: foreach (add[i]) list[add[i]] = add[i]; // add address to list
erase: foreach (add[i]) list.delete(add[i]);
endcase
endfunction