A normal form for free groups and free product of groups represents elements by reduced words. In a free group, adjacent inverse letters cancel; in a free product, alternating nonidentity syllables from different factors are unique. In an amalgamated free product, chosen coset representatives produce the corresponding reduced form relative to the common subgroup.
Every element of a free product has a unique expression in which each is a nonidentity element of one factor and adjacent syllables belong to different factors. The identity corresponds to the empty word.
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In group theory, the concept of "normal form" can refer to a variety of representations that provide a canonical way to express elements in certain types of groups, particularly free groups and free products of groups. ### Normal Form for Free Groups A **free group** is a group where the elements can be represented as reduced words over a set of generators, with no relations other than those that are necessary to satisfy the group axioms (e.g., inverses for each generator).