Closure operations for Schunck classes
Closure operations for Schunck classes
In his Canberra lectures on finite soluble groups, [3], Gaschütz observed that a Schunck class (sometimes called a saturated homomorph) is { Q , E φ , D 0 }-closed but not necessarily R 0 closed(*). In Problem 7·8 of the notes he then asks whether every { Q , …