$```$

entity circuit is

port$($ a$,$ b: in std$\_$logic;

y: out std$\_$logic$)$;

end circuit;

architecture structure of circuit is

component NOT$1$

port$($ a: in std$\_$logic;

b: out std$\_$logic$)$;

end component;

component AND$2$

port$($ a$,$ b: in std$\_$logic;

c: out std$\_$logic$)$;

end component;

component OR$2$

port$($ a$,$ b: in std$\_$logic;

c: out std$\_$logic$)$;

end component;

signal bnot: std$\_$logic;

signal anotb: std$\_$logic;

signal bnota: std$\_$logic;

begin

not$1\_2$: NOT$1$ port map$($b$,$ bnot$)$;

and$2\_1$: AND$2$ port map XXX;

and$2\_2$: AND$2$ port map YYY;

or$2\_1$: OR$2$ port map$($anotb$,$ ab$,$ y$)$;

end structure;

$```$

$\backslash ($ X X X $\backslash )$ : $($a$,$ bnot, abnot$)$ and YYY: $($a$,$ b$,$ ab$)$

$\backslash ($ X X X:$($a$,$ b n o t$)\backslash )$ and $\backslash ($ Y Y Y:$($a$,$ b$)\backslash )$

$\backslash ($ X X X $\backslash )$ : $($abnot$,$ y$)$ and YYY: $($ab$,$ y$)$

$\backslash ($ X X X:$($a $\backslash ),$ bnot, y$\backslash ()\backslash )$ and $\backslash (\backslash$mathrm$\{$YYY$\}$:$(\backslash$mathrm$\{$a$\},\backslash$mathrm$\{$b$\},\backslash$mathrm$\{$y$\})\backslash )$