def last(self): """ Return the last standard ribbon of ``self``. EXAMPLES:: sage: StandardRibbonShapedTableaux([2,2]).last() [[None, 1, 2], [3, 4]] """ return self.from_permutation(descents_composition_last(self.shape))
def last(self): """ Returns the first standard ribbon of ribbon shape shape. EXAMPLES:: sage: StandardRibbons([2,2]).last() [[1, 2], [3, 4]] """ return from_permutation(permutation.descents_composition_last(self.shape))