In a PDF of mine the special characters are encoded or something. When I copy paste them into ctrl+f they turn into something else. I found that:
ϵ turns to 2, ∩ turns to \, ⊆ is ↕, ⊂ is →, λ is |, √ is p, ∀ is 8, ∃ is 9. I hope this helps because I would LOVE to know what the tilde ~~~~ turns to??? I really need this. If you need I can find more special symbols. Thanks!