THE SYLOW THEOREMS

The converse of Lagrange’s theorem is false: if G is a finite group and d|#G, then there may not be a subgroup of G with order d. The simplest example of this is the group A4, of order 12, which has no subgroup of order 6. The Norwegian mathematician Peter Ludwig Sylow [1] discovered that a converse result is true when d is a prime power: if p is a prim