// Test math formulas.

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The sum of $a$ and $b$ is $a + b$.

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We will show that:
$[ a^2 + b^2 = c^2 ]$

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Prove by induction:
$[ \sum_{k=0}^n k = \frac{n(n+1)}{2} ]$

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// Test that blackboard style looks nice.
$[ f: \mathbb{N} \rightarrow \mathbb{R} ]$

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// Error: 1-10 expected '}' found EOF
$\sqrt{x$

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// Error: 2:1 expected closing bracket and dollar sign
$[a