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I aimed at the simplest possible example to introduce the main ideas in \
semidefinite programming. As a matter of fact, this problem does not even \
require optimization: we could simply do a bisection on the \[Alpha] \
\[Element] [0,1] interval and test for PPT on each step, until we find the \
SEP/ENT threshold. However, PPT conditions frequently appear as constraints \
in more complicated problems, so this SDP is a building block for those.\
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