1.1 --- a/src/Tools/isac/TODO.thy	Tue Jul 28 16:17:42 2020 +0200
     1.2 +++ b/src/Tools/isac/TODO.thy	Fri Jul 31 12:21:34 2020 +0200
     1.3 @@ -224,6 +224,19 @@
     1.4  text \<open>
     1.5    \begin{itemize}
     1.6    \item xxx          
     1.7 +  \item xxx
     1.8 +  \item make parser mutually recursive for Problem .. Solution
     1.9 +    preps. in Test_Parse_Isac:
    1.10 +      Test_Parse_Isac:
    1.11 +        subsubsection "problem_mini" shows a principal issue with recursive parsing
    1.12 +        probably due to !2! arguments of parser (as shown in Cookbook)
    1.13 +      Test_Parsers_Cookbook:
    1.14 +        (* recursive parser p.140 \<section>6.1 adapted to tokens: *) shows differences,
    1.15 +        which might help understanding the principal issue
    1.16 +    see also Test_Parsers  subsection "recursive parsing"
    1.17 +  \item xxx
    1.18 +  \item xxx          
    1.19 +  \item xxx          
    1.20    \item revisit bootstrap Calcelements. rule->calcelems->termC
    1.21      would be nice, but is hard: UnparseC.terms -> TermC.s_to_string
    1.22    \item xxx