$P \niton x$, but it does not work. How can I write the symbol
[Tex/LaTex] How to write $\notin$ backwards
After consulting The Comprehensive LaTeX Symbol List a few fonts provide such a symbol:
mathdesignhas a small version
$\notsmallowns$, but no normal sized one.
Note however that using one of these packages changes the complete font set. Of course you can rip this single symbol from a font that has it, let's try with
$\notni$from txfonts, surrounded by Latin Modern:
but the result is not convincing: