Verbal subgroup
In mathematics , in the area of abstract algebra known as group theory , a verbal subgroup is a subgroup of a group that is generated by all elements that can be formed by substituting group elements for variables in a given set of words . 
<triplet> abstract algebra <subj> mathematics <obj> part of <triplet> group theory <subj> mathematics <obj> subclass of <subj> abstract algebra <obj> part of <triplet> subgroup <subj> group theory <obj> part of <subj> group <obj> subclass of <triplet> group <subj> group theory <obj> studied by <triplet> words <subj> group theory <obj> part of