// 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 = (n(n+1))/2 $

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We know that:
$ floor(x/2) <= ceil(x/2) $

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// Test that blackboard style looks nice.
$ f: NN -> RR $

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// Error: 1:3 expected dollar sign
$a