Fix a reference in the tutorial
Fix a reference in the tutorial

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