Hi all, I have a list of coefficients (which are variables) and I want to remove duplicates. In my original file (from May 2015) I could use set and or unique now both of them give me the same error
TypeError: <class 'sage.manifolds.coord_func_symb.CoordFunctionSymbRing_with_category.element_class'> is not hashable
Whenever I try to use the same commands with another list I don't have any error. I'm still scratching my head. here is the notebook. I don't have enough karma to publish a link
cloud.sagemath.com/projects/263f082f-dc10-4817-a88d-d87700640552/files/Ask+sage.html
