[NTG-context] TOC chapter and section numbering

Hello,

I'm attempting to typeset a short book using ConTeXt (current version:
2020.08.09 22:03).

EXAMPLE:

\setuplist[content][alternative=c]

\setuplist[section][width=1.5em,margin=3em]

\starttext
\title{contents}
\placecontent

\startchapter[title={Introductory}]
\startsection[title={The concept of a function}]
\stopsection
\startsection[title={Extension and intension}]
\stopsection
\startsection[title={Functions of several variables}]
\stopsection
\startsection[title={Abstraction}]
\stopsection
\stopchapter

\startchapter[title={Lambda-Conversion}]

\startsection[title={Primitive symbols, and formulas}]
\stopsection
\startsection[title={Conversion}]
\stopsection
\startsection[title={Fundamental theorems on well-formed formulas and on the
normal form}]
\stopsection
\stopchapter

\stoptext

I would like all the chapters to be prefixed with "Chapter RN." and the
sections to keep a single count,
for example:

Chapter I. Introductory .....
1. The concept of a function
2. Extension and intension
3. Functions of several variables
4. Abstraction
Chapter II. Lambda Conversion .....
5. Primitive symbols and formulas
6. Conversion
7. Fundamental theorems on well-formed formulas and on the normal form

I tried to the following for the chapters:

Which appeared to generate the prefix correctly but it overlapped the title.

Any help would be greatly appreciated. Thanks

Adrian
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