The semantics of a WHILE command C is expressed by the judgement Ctoo' where o and o' are stores for WHILE. For instance, {X 27, Y nil} describes a store that maps program variable X to value 27 and variable Y to value nil. Recall that is the encoding of number n as WHILE-data. i. Give an example of a single WHILE command C such that CH(X: nil} {X: 27}