Would your algorithm be able to determine that any of

the following PCP problems are unsolvable $($or probably so$)?$ If not,

can you think of any modifications that you could make so that it is

able to determine unsolvability?

$$

$111$

$11$

$100$

$011$

$0$

$100$

$$

$111$

$001$

$001$

$0$

$1$

$111$

$$

$110$

$1$

$1$

$01$

$0$

$110$