ChengsongTanPhdThesis/Chapters/Chapter2.tex
changeset 524 947cbbd4e4a7
parent 519 856d025dbc15
child 525 d8740017324c
equal deleted inserted replaced
523:4e195992ef41 524:947cbbd4e4a7
   898 
   898 
   899 %-----------------------------------
   899 %-----------------------------------
   900 %	SUBSECTION 1
   900 %	SUBSECTION 1
   901 %-----------------------------------
   901 %-----------------------------------
   902 \section{Specifications of Certain Functions to be Used}
   902 \section{Specifications of Certain Functions to be Used}
   903 To be completed.
   903 Here we give some functions' definitions, 
   904 
   904 which we will use later.
   905 
   905 \begin{center}
       
   906 \begin{tabular}{ccc}
       
   907 $\retrieve \; \ACHAR \, \textit{bs} \, c \; \Char(c) = \textit{bs}
       
   908 \end{tabular}
       
   909 \end{center}
   906 
   910 
   907 
   911 
   908 %----------------------------------------------------------------------------------------
   912 %----------------------------------------------------------------------------------------
   909 %	SECTION  correctness proof
   913 %	SECTION  correctness proof
   910 %----------------------------------------------------------------------------------------
   914 %----------------------------------------------------------------------------------------
   931 prove some stepwise properties of lexing nicely:
   935 prove some stepwise properties of lexing nicely:
   932 \begin{lemma}\label{flexStepwise}
   936 \begin{lemma}\label{flexStepwise}
   933 $\textit{flex} \; r \; f \; s@[c] \; v= \flex \; r \; f\; s \; (\inj \; (r\backslash s) \; c \; v) $
   937 $\textit{flex} \; r \; f \; s@[c] \; v= \flex \; r \; f\; s \; (\inj \; (r\backslash s) \; c \; v) $
   934 \end{lemma}
   938 \end{lemma}
   935 
   939 
   936 And for $\blexer$ we have something with stepwise properties like $\flex$ as well,
   940 And for $\blexer$ we have a function with stepwise properties like $\flex$ as well,
   937 called $\retrieve$:
   941 called $\retrieve$\ref{retrieveDef}.
   938 \[
       
   939 \retrieve \; \ACHAR \, \textit{bs} \, c \; \Char(c) = \textit{bs}
       
   940 \]
       
   941 $\retrieve$ takes bit-codes from annotated regular expressions
   942 $\retrieve$ takes bit-codes from annotated regular expressions
   942 guided by a value.
   943 guided by a value.
   943 $\retrieve$ is connected to the $\blexer$ in the following way:
   944 $\retrieve$ is connected to the $\blexer$ in the following way:
   944 \begin{lemma}\label{blexer_retrieve}
   945 \begin{lemma}\label{blexer_retrieve}
   945 $\blexer \; r \; s = \decode  \; (\retrieve \; (\internalise \; r) \; (\mkeps \; (r \backslash s) )) \; r$
   946 $\blexer \; r \; s = \decode  \; (\retrieve \; (\internalise \; r) \; (\mkeps \; (r \backslash s) )) \; r$