Hello, Thank you for the answer.

if you have a proper opentype math Font…

As you know, Baskervald doesn’t come with an open type math version. Moreover the mapping mechanism works well with open type text fonts and is powerful and very general. It’s my prefered way of solving my problem. So I reiterate my questions: Question 1: Where do I define my own vector mapping? Should I modify ConTeXt’s source code in the math-ttv.lua file? How do I define my own baskervald-math.lua and what should I write in it (for example for mapping Pagella’s upright mathematic glyphs to Baskervald’s upright glyphs)? Question 2: I am forced to put the goodies file baskervald-math.lfg in Book/Volume1/Chapter1. When I put it in Book and compiled chapter1.tex separately, ConTeXt failed to find it. What should I do to have the file baskervald-math.lfg in the Book directory and make ConTeXt find it when invoked from Book/Volume1/Chapter1. Thank you. Joas.