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