+ The dual of the Schur cone is the "downward monotonic cone"
+ [GourionSeeger]_, whose elements' entries are in non-increasing
+ order::
+
+ sage: set_random_seed()
+ sage: n = ZZ.random_element(10)
+ sage: K = schur_cone(n).dual()
+ sage: x = K.random_element()
+ sage: all( x[i] >= x[i+1] for i in xrange(n-1) )
+ True
+