記号 $a$ についての正規表現(regular expressions)のゾゾウスキ導分(Brzozowski derivative)は次のように定義されます.\[D_{a}(\emptyset)=D_{a}(\varepsilon)=\varepsilon\]\[D_{\varepsilon}(a)=a\]\[\begin{eqnarray}D_{a}(b)= \begin{cases} \varepsilon & if\ b=a\\ \emptyset & otherwise \end{cases}\end{eqnarray}\]\[\begin{eqnarray}D_{a}(E+F)= \begin{cases} D_{a}(E)F+D_{a}(F) & if\ \varepsilon \in \mathcal{L}\\D_{a}(E)F & o th e rw ise \end{cases}\end{eqnarray}\]\[D_{a}(E^{*})=D_{a}(E)E^{*}\]\[D_{\varepsilon}(E)=E\]\[D_{wa}(E)=D_{a}(D_{w}(E))\]
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