SIGNAL a : BIT :$=\text{'}1\text{'}$;

SIGNAL b : BIT$\_$VECTOR $(3$ DOWNTO $0)$ :$="1100"$;

SIGNAL c : BIT$\_$VECTOR $(3$ DOWNTO $0)$ :$="0010"$;

SIGNAL d : BIT$\_$VECTOR $(7$ DOWNTO $0)$;

SIGNAL e : INTEGER RANGE $0$ TO $255$;

SIGNAL f : INTEGER RANGE $-128$ TO $127$;

Determine if the VHDL operations are legal or illegal:

b$(0)$ AND a

a $+$ d$(7)$

NOT b XNOR c

c $+$ d

e $-$ f

IF $($b$=$a$)...$

IF $($f$/=$e$)...$

IF $($e$>$d$)...$

b sra $1$

c srl $-2$

f ror $3$

e$*3$

$5**5$

f$/4$

e$/3$

d $<=$ c

d$(6$ DOWNTO $3)$ :$=$ b

e $<=$ d

f :$=100$