Exercises on Section 3

Each of (a)–(c) is a member of one of the sets given in (i)–(iii). Say which item comes from which set.

Sets: (i) SetOfSeqOfChar. (ii) SeqOfSetOfChar. (iii) SeqOfSeqOfChar.

• (a) {“error1”, “error2”, “error3”}.

• (b) [“error1”, “error2”, “error3”].

• (c) [{‘e’,‘1’}, {‘T’}, {‘q’,‘w’,‘e’,‘r’,‘t’,‘y’}].

Let Mix be the disjoint union Int  Char. What is the length of the following sequence from SeqOfMix?