diff -r aeb0bc2d1812 -r e7ba4da53930 etnms/etnms.tex --- a/etnms/etnms.tex Sun Jan 12 22:49:23 2020 +0000 +++ b/etnms/etnms.tex Mon Jan 13 16:57:13 2020 +0000 @@ -180,57 +180,39 @@ only.need to \emph{not} change the language, but also not change the value (computed result). -\bigskip\noindent\rule[1.5ex]{\linewidth}{5pt} -Do you want to keep this? You essentially want to say that the old -method used retrieve, which unfortunately cannot be adopted to -the simplification rules. You could just say that and give an example. -However you have to think about how you give the example....nobody knows -about AZERO etc yet. Maybe it might be better to use normal regexes -like $a + aa$, but annotate bitsequences as subscript like $_1(_0a + _1aa)$. + -\bigskip\noindent\rule[1.5ex]{\linewidth}{5pt} -REPLY:\\ -Yes, I am essentially saying that the old method -cannot be adopted without adjustments. -But this does not mean we should skip -the proof of the bit-coded algorithm -as it is still the main direction we are looking into -to prove things. We are trying to modify -the old proof to suit our needs, but not give -up it totally, that is why i believe the old -proof is fundamental in understanding -what we are doing in the past 6 months. +For this we have started with looking at the original proof that +established that the bitsequence algorithm produces the same result as +the algorithm not using bitsequences. Formally this proof estabilshed -\bigskip\noindent\rule[1.5ex]{\linewidth}{5pt} - -The correctness proof of \begin{center} $\blexer \; r^\uparrow s = \lexer \;r \;s$ \end{center} -\noindent -might provide us insight into proving -\begin{center} -$\blexer \; r^\uparrow \;s = \blexers \; r^\uparrow \;s$ -\end{center} + \noindent -(that is also -why we say the new proof builds on the older one). -The proof defined the function $\flex$ as another way of -expressing the $\lexer$ function: -\begin{center} -$\lexer \;r\; s = \flex \;\textit{id} \; r\;s \;(\mkeps \; r\backslash s)$ -\end{center}. -\noindent -(proof for the above equality will be explained later) -The definition of $flex$ is as follows: +The proof used two ''tricks", One is that it defined + a $\flex$-function + \begin{center} \begin{tabular}{lcl} $\textit{flex} \;r\; f\; (c\!::\!s) $ & $\dn$ & $\textit{flex} \; (r\backslash c) \;(\lambda v. f (inj \; r \; c \; v)) \;s$ \\ $\textit{flex} \;r\; f\; [\,] $ & $\dn$ & $f$ \end{tabular} \end{center} + \noindent -here $\flex$ essentially does lexing by +and then proved for the right-hand side in \eqref{lexer} + +\begin{center} +$\lexer \;r\; s = \flex \;\textit{id} \; r\;s \;(\mkeps \; r\backslash s)$ +\end{center}. + + +\noindent\rule[1.5ex]{\linewidth}{1pt} + +\noindent +The $\flex$-function essentially does lexing by stacking up injection functions while doing derivatives, explicitly showing the order of characters being injected back in each step.