Let S be the set of all strings of 0’s and 1’s, and define l:S→Z^{nonneg} by l(s)=the length of s, for all strings s in S.

a. Is l one-to-one? Prove or give a counterexample.

b. Is l onto? Prove or give a counterexample.

^{nonneg} by l(s)=the length of s, for all strings s in S.

a. Is l one-to-one? Prove or give a counterexample.

b. Is l onto? Prove or give a counterexample.