make FreeGroupElm a subclass of list instead of basic
make FreeGroupElm a subclass of list instead of basic

sampadsaha5/sympy,aktech/sympy,kaushik94/sympy,hargup/sympy,postvakje/sympy,ChristinaZografou/sympy,yashsharan/sympy,souravsingh/sympy,madan96/sympy,kaushik94/sympy,drufat/sympy,sampadsaha5/sympy,skidzo/sympy,drufat/sympy,sampadsaha5/sympy,hargup/sympy,souravsingh/sympy,chaffra/sympy,chaffra/sympy,jaimahajan1997/sympy,postvakje/sympy,souravsingh/sympy,skidzo/sympy,yashsharan/sympy,chaffra/sympy,drufat/sympy,ChristinaZografou/sympy,yashsharan/sympy,jaimahajan1997/sympy,ChristinaZografou/sympy,rahuldan/sympy,aktech/sympy,aktech/sympy,postvakje/sympy,madan96/sympy,kaushik94/sympy,jaimahajan1997/sympy,hargup/sympy,madan96/sympy,rahuldan/sympy,rahuldan/sympy,skidzo/sympy