declare -ai a
a[0]=4
declare -n b='a[0]'

b+=1 ; declare -p a

declare b+=1 ; declare -p a

unset a b
unset -n b

######
declare -ai a=(1)
declare -in b="a[0]"
declare -p a b

b+=1 ; declare -p a b
b+=1 ; declare -p a b
b+=0 ; declare -p a b

unset a b

#####
declare -ai a=(1)
declare -n b="1"
declare -p a
declare -np b

unset a ; unset -n b

#####
declare -ai a=('4');
declare -n b='a[0]';
declare -ni b;		# this should maybe not be allowed, but it is for now
declare -p a b

b+=2;
declare -p a b 

unset a ; unset -n b

#####
f()
{
	local -a a=('' 'foo');
        local -n b=a[1];
        echo $b;
        b+=\ bar;
        echo $b;
        declare -p a b;
}
f

declare -a a=('' 'foo');
declare -n b=a[1];
echo $b;
b+=\ bar;
echo $b;
declare -p a b

unset a ; unset -n b

unset -f f
f()
{
        local -ai a=(0 12);
        local -n b=a[1];
        echo $b;
        b+=4;
        echo $b;
        declare -p a;
}
f

declare -ai a=(0 12);
declare -n b=a[1];
echo $b;
b+=4;
echo $b;
declare -p a

unset a ; unset -n b