Latex code for the "not equivalent" symbol

[Math Amateur]

I have just posted on the Linear and Abstract Algebra forum ... and the post needs a "not equivalent" symbol as shown in Rotman's Proposition 1.58 part (ii) see below ...

Can someone please help with the latex code for this symbol?

PeterProposition 1,58 in Rotman's Abstract Algebra reads as follows:View attachment 4525
https://www.physicsforums.com/attachments/4526See Part (ii) of the above for the desired "not equivalent" symbol ...

Peter

 

[Evgeny.Makarov]

[m]r\not\equiv r'\pmod{m}[/m] gives $r\not\equiv r'\pmod{m}$. For slightly more information, see StackExchange.