sage: (x*x)*(x*x*x) == x^5
True
+ We also know that powers operator-commute (Koecher, Chapter
+ III, Corollary 1)::
+
+ sage: set_random_seed()
+ sage: x = random_eja().random_element()
+ sage: m = ZZ.random_element(0,10)
+ sage: n = ZZ.random_element(0,10)
+ sage: Lxm = (x^m).matrix()
+ sage: Lxn = (x^n).matrix()
+ sage: Lxm*Lxn == Lxn*Lxm
+ True
+
"""
A = self.parent()
if n == 0: