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\begin{document}

Test of unicode—that was an em dash. Here is some stuff in math mode
\(∫ α \, dx = y_⊙  − x²\). And here is stuff out of math mode: Hα is
stronger than Hβ. \(α + β = 3.3 × 10^{22} \mathrm{\ cm²}\) 
A Polish name: Grażyna Stasińska. A Slovenian name: Slavoj
Žižek. Angular separation is 3°5′50′′. The star θ¹ Ori C. 
\begin{displaymath}
  ½∫ Ξ₀ dz = ℏc/λ ⇒ ϑ ⊂ \{⊼, ⋓, ∡\} \  □
\end{displaymath}
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