i$.$e$.,$ each symbol in the alphabet is a column consisting of three bits. For a string w in $\backslash$Sigma

$$

$3$ we

consider the bits in each row as a binary representation of a number specified from least significant

bit to most significant bit. Let L be the language of all w in $\backslash$Sigma

$$

$3$

such that the third row represents

the sum of the first and second row $($as binary numbers$).$ For example,