hws/Der.tex
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    38 \noindent
    38 \noindent
    39 where $\Sigma^*$ is in our case the set of all strings (what follows in this section
    39 where $\Sigma^*$ is in our case the set of all strings (what follows in this section
    40 also holds for any kind of ``domain'', like the set of all integers or
    40 also holds for any kind of ``domain'', like the set of all integers or
    41 the set of all binary trees, etc). Let us assume $P(s)$ is a property that
    41 the set of all binary trees, etc).\footnote{NOTE: In the videos and slides I use \textit{UNIV} as notation for $\Sigma^*$. } Let us assume $P(s)$ is a property that
    42 is about strings, for example $P(s)$ could be ``the string $s$ has
    42 is about strings, for example $P(s)$ could be ``the string $s$ has
    43 an even length'', or ``the string $s$ starts with the letter
    43 an even length'', or ``the string $s$ starts with the letter
    44 \texttt{a}''. Every such property carves out a subset of strings from
    44 \texttt{a}''. Every such property carves out a subset of strings from
    45 $\Sigma^*$, which in the picture above is depicted as a grey
    45 $\Sigma^*$, which in the picture above is depicted as a grey
    46 circle. This subset of strings is often written as a comprehension like
    46 circle. This subset of strings is often written as a comprehension like