Always push a new env cell on define unless the previous cell was undefined.
Always push a new env cell on define unless the previous cell was undefined.

holmescn/chibi-scheme,norton/chibi-scheme,holmescn/chibi-scheme,holmescn/chibi-scheme,holmescn/chibi-scheme,norton/chibi-scheme,norton/chibi-scheme,norton/chibi-scheme,holmescn/chibi-scheme,norton/chibi-scheme,norton/chibi-scheme