Non-Pictorial Core

<..html private array/tabular..>
 \def\:temp[#1]#2{%
   <.init conds for @mkpream.>%
   \setbox\@arstrutbox\hbox{}%
   \@mkpream{#2}%
   \edef\@preamble{%
         <.ialign for html @array.>}%
   \let\@startpbox\@@startpbox \let\@endpbox\@@endpbox
   \let\tabularnewline\\%
   \if #1t\vtop \else \if#1b\vbox \else \vcenter \fi\fi
   \bgroup \def\v:TBL{#1}%
     \let\par\@empty \let\protect\relax
     \lineskip\z@skip\baselineskip\z@skip
     \ifx \EndPicture\:UnDef
        \SaveMkHalignConfig <.@array configuration for MkHalign.>%
     \else \let\@sharp=##\fi    \HRestore\noalign
     \@preamble}
 \HLet\@array=\:temp
 <.set cr for @array.>
 <.latex: show paragraphs in array par box.>
 -_-_-

The next example fails under dblatex without the definition of \cr that follows.

\documentclass{article} 
\begin{document} 
   \begin{tabular}{l} \relax 
     $\begin{array}{c}4\end{array}$ 
   \end{tabular} 
\end{document} 

<..set cr for @array..>
 \let\oo:@array\@array
 \def\@array{%
    \ifx\EndPicture\:UnDef\else
       \iffalse{\fi
       \expandafter\let\expandafter\cr\csname 0cr\endcsname
       \expandafter\let\expandafter\crcr\csname 0crcr\endcsname
       \iffalse}\fi
    \fi
    \oo:@array
 }
 -_-_-

<..latex: show paragraphs in array par box..>
 \let\:tempc=\@@startpbox
 \append:defI\:tempc{\everypar{\HtmlPar}\a:arrayparbox}%
 \HLet\@@startpbox=\:tempc
 -_-_-

<..latex lttab..>+
 \NewConfigure{arrayparbox}{1}
 -_-_-

<..html private array/tabular..>+
 \def\:tempc{\relax
    \ifx \HCol\:UnDef \else \ifnum\HCol=1 \a:endarray\fi \fi
    \crcr\ifx \EndPicture\:UnDef \EndMkHalign
    \else \egroup\fi \egroup}
 \HLet\endarray\:tempc
 \def\:tempc{\relax
    \ifx \HCol\:UnDef \else \ifnum\HCol=1 \a:endarray\fi \fi
    \crcr\ifx \EndPicture\:UnDef
    \EndMkHalign\else \egroup\fi \egroup $\egroup}
 \HLet\endtabular\:tempc
 \expandafter \let \csname endtabular*\endcsname=\endtabular
 \expandafter\def\csname tabular*\endcsname#1{\tabular}
 \expandafter\def\csname before:begintabular*\endcsname{\csname
    before:begintabular\endcsname}
 \expandafter\def\csname ontabular*:list\endcsname{\csname
    ontabular:list\endcsname}
 -_-_-

<..latex lttab..>+
 \NewConfigure{endtabular}{1}
 \NewConfigure{endarray}{1}
 -_-_-