Dear List,

Working with ConTeXt MK IV version 2016.07.18, I need sometimes within a 
text in French I am working on, some Greek words or sentences, rarely 
Chinese and Arabic words, mainly names and a few words.

Then, I use this general preamble (thanks to Pablo Rodriguez):

\setuplanguage[fr][patterns={fr,agr}]

\mainlanguage[fr]

\setuplayout [backspace=40mm]

\setuppagenumbering[alternative=doublesided, location={header, inmargin}]

\setupmargindata[inmargin][location=inner, 
style={\ssx\setupinterlinespace[line=2.8ex]}]

\setupmarginframed[inmargin][align=right]

\setupbodyfontenvironment[default][em=italic]


% Hereafter the commands for Greek and Chinese

\definefallbackfamily[mainface][serif][Theano Didot][preset=range:greek, 
it={Old Standard Italic}, force=yes]

\definefallbackfamily [mainface] [rm] [ipaexmincho] 
[range=cjkunifiedideographs]

\definefontfamily [mainface] [serif] [GaramondNo8][sc=NewG8 Regular SC]

\definefontfamily [mainface] [sans] [FreeSans] [rscale=0.7]


All is working well, but if I add these lines below to the pramble:


\definefallbackfamily [mainface] [sans] [hussaininastaleeq] [range=arabic]

  \definefontfamily [mainface] [serif] [GFS Didot]
(where hussainiastaleeq and GFS Didot fonts are pre-installed, and load 
with a '|mtxrun --script fonts --reload' command), then Arabic words are 
not printed in the PDF file.

One more question : in the English translitteration, the name of the 
tenth century Arabic philosopher, Farabi, is |Abū Naṣr al-Fārābī (with 
diacritic signs on wovels and under the 's' of "Nasr"). Do someone knows 
how to deal with these diacritic signs ?
Thak you very much.
JP