Groups and Their Graphs: Clarifications of Normal Subgroup Theorem and Test for Normal Subgroup Elements
On page 123 of “Gropus and Their Graphs” by Grossman and Magnus I struggled understanding Theorem 6 and the test it provides. The theorem read more clearly for me with the following substitution: “the set K that contains all elements of G such that...” becomes “the set K containing every element of the group G such that...” The following paragraph that contained the test was easier for me to understand with the following substitution: “If f maps all elements onto I...” becomes “If f maps all elements of G onto I...” Hope this helps! Any comments or questions?