In
group theory, a
word is any written product of
group elements and their inverses. For example, if
x,
y and
z are elements of a group
G, then
xy,
z-1xzz and
y-1zxx-1yz-1 are words in the set {
x,
y,
z}. Two different words may evaluate to the same value in
G, or even in every group. Words play an important role in the theory of
free groups and
presentations, and are central objects of study in
combinatorial group theory.