2021-03-24 17:28:47 +0200 received badge ● Famous Question (source) 2016-08-06 16:42:16 +0200 received badge ● Good Question (source) 2016-08-06 16:42:08 +0200 received badge ● Notable Question (source) 2014-09-23 12:10:00 +0200 received badge ● Nice Question (source) 2014-09-22 20:01:59 +0200 asked a question Create new structure class and define its element Hello. I have a problem with the Element class of a new structure. In detail, I am defining a new subclass of Polynomial Ring via class MyElement(sage.rings.polynomial.multi_polynomial_element.MPolynomial_polydict): pass class MyAlgebra(sage.structure.unique_representation.UniqueRepresentation, sage.rings.polynomial.multi_polynomial_ring.MPolynomialRing_polydict): Element=MyElement  Now, I have: sage: A=MyAlgebra(QQ,1,'x',order="lex") sage: (x,)=A.gens() sage: type(x)  While: sage: a=MyElement(A,{(1,):1}) sage: type(a)  Why isn't the element x of type MyElement? 2014-04-25 00:15:11 +0200 received badge ● Popular Question (source) 2013-02-25 07:43:13 +0200 received badge ● Nice Question (source) 2013-02-24 22:02:17 +0200 received badge ● Student (source) 2013-02-24 12:10:28 +0200 received badge ● Editor (source) 2013-02-24 12:03:22 +0200 asked a question How are list of matrices printed by sage? If I construct a list of matrices and let sage print it, the matrices are (correctly) aligned on the top: sage: A=matrix([[1,2],[3,4]]) sage: [A,A] [ [1 2] [1 2] [3 4], [3 4] ]  Howewer, this is not the output of the __repr__ function of a list: compare: sage: print [A,A].__repr__() [[1 2] [3 4], [1 2] [3 4]]  I would like to construct an object whose output is on more than one lines (like a matrix), and I would like a list of these objects to be printed aligned on the top (like with the matrices in the first example above). How can I do that?