🚀 go-pugleaf

The following AMS-Latex file

     \documentstyle[amsfonts]{amsart}
     \begin{document}
     Hello world
     \end{document}

gives me the following latex error

This is TeX, Version 3.0 [PD VMS 3.2/DECUS] (preloaded format=lplain 90.8.23)
(VC$18:[APN177D.TEXSRC.LATEX]TEMP.TEX;1
LaTeX Version 2.09 <7 Dec 1989>
(TEX_DISK:[TEX.INPUTS.AMSLATEX]AMSART.STY;1
Document style `AMSART' v1.0c <90/06/26> (RK, MJD)
English documentation         <90/06/26> (MJD)
(TEX_DISK:[TEX.INPUTS.AMSLATEX]AMSTEX.STY;1
Style option: `amstex'  v1.0A <90/07/03> (FMi, RmS; MJD)
English documentation         <90/07/03> (FMi, RmS; MJD)
(TEX_DISK:[TEX.INPUTS.AMSLATEX]AMSTEXT.STY;1
! The style option `amstext' does not make sense if you do not use a
format with the new font selection scheme..

Can anybody spot the silly mistake that I am making here?

Thanks heaps etc. -- and a thousand pardons if this is a BOZO type mistake.