%
% Some redefs
%
\def\cals@issue@rowsep{\vbox{\hrule width400pt height4pt depth0pt}}
\def\cals@issue@row{\nointerlineskip \box\cals@current@row}

\def\cals@current@rs@above{rsabove}
\def\cals@current@rs@below{rsbelow}
\renewcommand\lastrule{}

\def\somerow#1#2{%
\setbox\cals@current@row=\vbox{\hrule width#1 height#1 depth0pt}%
\let\cals@current@context=#2%
\cals@row@dispatch
}

\def\bodyrowI{\somerow{10pt}b}
\def\bodyrowII{\somerow{20pt}b}
\def\headrowI{\somerow{110pt}h}
\def\headrowII{\somerow{120pt}h}
\def\footrowI{\somerow{210pt}f}
\def\footrowII{\somerow{220pt}f}

%
% Normal table
%
\setbox0=\vbox{%
\headrowI
\headrowII
\headrowI
\bodyrowI
\bodyrowII
\bodyrowI
\footrowI
\footrowII
\footrowI
}
\showbox0

%
% Make a break
%
\setbox0=\vbox{%
\def\cals@thead@tokens{\headrowI\headrowII}
\def\cals@tfoot@tokens{\footrowI}
\bodyrowI
\tbreak{\break}
\bodyrowII
}
\showbox0

%
% Span
%
\setbox0=\vbox{%
\bodyrowI
  \let\cals@ifInRspan=\cals@iftrue
  \let\cals@ifLastRspanRow=\cals@iffalse
\bodyrowII
  \let\cals@ifLastRspanRow=\cals@iftrue
\bodyrowI
  \let\cals@ifInRspan=\cals@iffalse
\bodyrowII
}
\showbox0