Fix the Pauli matrix simplification bug.
Fix the Pauli matrix simplification bug.

hrashk/sympy,postvakje/sympy,jamesblunt/sympy,saurabhjn76/sympy,VaibhavAgarwalVA/sympy,bukzor/sympy,pbrady/sympy,yukoba/sympy,kaushik94/sympy,lidavidm/sympy,Shaswat27/sympy,ahhda/sympy,shikil/sympy,atreyv/sympy,AkademieOlympia/sympy,jamesblunt/sympy,souravsingh/sympy,wyom/sympy,ga7g08/sympy,saurabhjn76/sympy,drufat/sympy,sahilshekhawat/sympy,hargup/sympy,oliverlee/sympy,AkademieOlympia/sympy,aktech/sympy,jbbskinny/sympy,ahhda/sympy,madan96/sympy,kmacinnis/sympy,cswiercz/sympy,wanglongqi/sympy,pbrady/sympy,jerli/sympy,rahuldan/sympy,MechCoder/sympy,Designist/sympy,Curious72/sympy,iamutkarshtiwari/sympy,debugger22/sympy,Shaswat27/sympy,pandeyadarsh/sympy,Designist/sympy,rahuldan/sympy,bukzor/sympy,iamutkarshtiwari/sympy,farhaanbukhsh/sympy,Sumith1896/sympy,sampadsaha5/sympy,kaichogami/sympy,pbrady/sympy,Titan-C/sympy,diofant/diofant,beni55/sympy,shikil/sympy,Curious72/sympy,flacjacket/sympy,grevutiu-gabriel/sympy,kevalds51/sympy,mcdaniel67/sympy,sunny94/temp,grevutiu-gabriel/sympy,Designist/sympy,pandeyadarsh/sympy,AunShiLord/sympy,cswiercz/sympy,sahmed95/sympy,oliverlee/sympy,lidavidm/sympy,emon10005/sympy,farhaanbukhsh/sympy,kmacinnis/sympy,liangjiaxing/sympy,Sumith1896/sympy,Arafatk/sympy,abloomston/sympy,shipci/sympy,jerli/sympy,Shaswat27/sympy,emon10005/sympy,atsao72/sympy,abhiii5459/sympy,chaffra/sympy,srjoglekar246/sympy,yukoba/sympy,toolforger/sympy,lindsayad/sympy,ChristinaZografou/sympy,skidzo/sympy,mafiya69/sympy,lidavidm/sympy,beni55/sympy,toolforger/sympy,debugger22/sympy,oliverlee/sympy,saurabhjn76/sympy,vipulroxx/sympy,maniteja123/sympy,chaffra/sympy,shipci/sympy,vipulroxx/sympy,emon10005/sympy,wanglongqi/sympy,Arafatk/sympy,debugger22/sympy,ga7g08/sympy,lindsayad/sympy,lindsayad/sympy,Curious72/sympy,atsao72/sympy,grevutiu-gabriel/sympy,asm666/sympy,hrashk/sympy,ga7g08/sympy,Mitchkoens/sympy,AunShiLord/sympy,madan96/sympy,shipci/sympy,Davidjohnwilson/sympy,Davidjohnwilson/sympy,bukzor/sympy,chaffra/sympy,AunShiLord/sympy,cswiercz/sympy,Arafatk/sympy,farhaanbukhsh/sympy,atreyv/sympy,aktech/sympy,yukoba/sympy,jaimahajan1997/sympy,skirpichev/omg,sunny94/temp,kumarkrishna/sympy,Mitchkoens/sympy,souravsingh/sympy,dqnykamp/sympy,mafiya69/sympy,ChristinaZografou/sympy,garvitr/sympy,drufat/sympy,liangjiaxing/sympy,amitjamadagni/sympy,sunny94/temp,wyom/sympy,iamutkarshtiwari/sympy,Davidjohnwilson/sympy,meghana1995/sympy,kevalds51/sympy,garvitr/sympy,sahilshekhawat/sympy,abloomston/sympy,dqnykamp/sympy,Gadal/sympy,mcdaniel67/sympy,jaimahajan1997/sympy,cccfran/sympy,wyom/sympy,moble/sympy,kmacinnis/sympy,mafiya69/sympy,garvitr/sympy,Mitchkoens/sympy,liangjiaxing/sympy,ahhda/sympy,beni55/sympy,jbbskinny/sympy,maniteja123/sympy,VaibhavAgarwalVA/sympy,VaibhavAgarwalVA/sympy,jerli/sympy,hrashk/sympy,yashsharan/sympy,dqnykamp/sympy,Vishluck/sympy,shikil/sympy,madan96/sympy,abloomston/sympy,abhiii5459/sympy,toolforger/sympy,Titan-C/sympy,skidzo/sympy,sampadsaha5/sympy,kaushik94/sympy,jaimahajan1997/sympy,kaichogami/sympy,skidzo/sympy,pandeyadarsh/sympy,maniteja123/sympy,mcdaniel67/sympy,sahmed95/sympy,vipulroxx/sympy,sampadsaha5/sympy,jbbskinny/sympy,Gadal/sympy,ChristinaZografou/sympy,abhiii5459/sympy,MridulS/sympy,AkademieOlympia/sympy,kaushik94/sympy,wanglongqi/sympy,yashsharan/sympy,kaichogami/sympy,asm666/sympy,Vishluck/sympy,Gadal/sympy,sahmed95/sympy,Vishluck/sympy,sahilshekhawat/sympy,MechCoder/sympy,yashsharan/sympy,cccfran/sympy,postvakje/sympy,drufat/sympy,meghana1995/sympy,meghana1995/sympy,hargup/sympy,MridulS/sympy,asm666/sympy,postvakje/sympy,atsao72/sympy,cccfran/sympy,atreyv/sympy,moble/sympy,kumarkrishna/sympy,kevalds51/sympy,moble/sympy,Titan-C/sympy,rahuldan/sympy,aktech/sympy,MechCoder/sympy,amitjamadagni/sympy,kumarkrishna/sympy,hargup/sympy,jamesblunt/sympy,Sumith1896/sympy,souravsingh/sympy,MridulS/sympy