Description: Define the class of
words over a set. A word (or sometimes also
called a string) is a finite sequence of symbols from a set
(alphabet)
. Definition
in section 9.1 of [AhoHopUll] p. 318. The
domain is
forced so that two words with the same symbols in the same order will be
the same. This is sometimes denoted with the Kleene star, although
properly speaking that is an operator on languages. (Contributed by FL,
14-Jan-2014.) (Revised by Stefan O'Rear, 14-Aug-2015.) (Revised by
Mario Carneiro, 26-Feb-2016.) |