Supress chapter number in sections

[Randall Skelton <randall.skelton@gmail.com>]

I've fiddled with almost every parameter in sethead but cannot seem to
find the correct one.  I'd like to suppress the chapter numbers in a
relatively large document such that numbering of sections, tables,
figures and equations begins at 1 instead of 1.1.  Is there a simple
way to do this?

Here are how my chapters and sections are currently defined:

\def\MyChapterText#1{\leftaligned{#1}}

\setuphead[Topic,chapter]
  [textcommand=\MyChapterText,
   textstyle={\switchtobodyfont[Titling,20pt]\sc},
   color=black,
   number=no,
   page=right,
   continue=no,
   header=empty,
   distance=0pt,
   before=\vbox to 3cm\bgroup,
   after=\vss\egroup]

\def\MySectionText#1{\switchtobodyfont[12pt]\sc\lowercase{#1}}

\setuphead[Subject, section]
  [textcommand=\MySectionText,
   style={\sc},
   color=black,
   before={\blank[2*big]},
   after={\blank[2*big]}]

Many thanks,
Randall