11. "' Inversive activities "'are processes which self internalise the action concerned. 12. Every " E "-inversive semigroup is regular, but not vice versa. 13. For example, a person who has an Inversive personality internalises his emotions from any exterior source. 14. In 1926 he wrote a dissertation " Differential Invariants of Inversive Geometry " for his doctoral degree. 15. For graduate study, Boyd went to Johns Hopkins University where he studied inversive geometry with Frank Morley. 16. Continuing to collaborate with Morley, they co-wrote a paper on algebraic inversive invariants in 1930. 17. The concept of " E "-inversive semigroup was introduced by Gabriel Thierrin in 1955. 18. Semigroups in this class have also been called "'0-inversive semigroups . "' 19. Another example concerns inversive geometry as advanced by Ludwig Immanuel Magnus, which can be considered synthetic in spirit. 20. Thus inversive geometry, a larger study than grade school transformation geometry, is usually reserved for college students.
