$6\mathrm{.}1$: The first known correct software solution to the critical$-$

section problem for two processes was developed by Dekker.

The two processes, $P0$ and $P1,$ share the following variables:

boolean flag$[2]$;$//$

int turn;

do ${?}_{\text{f}\text{l}\text{a}\text{g}[i]}=$ true; $,$