Thank you very much Kevin! You gave me a lot of valuable information! You told me about Temml; well, that took to me to katex.js and with katex I was able to show TeX equations on Readium (and also in Sigil!
) Scripts plus all fonts take 1MB but the scripts also works with just the "Main" font that takes 400KB. It's very much lighter than MathJax. And equations looks great. Tomorrow I will post an epub so you can watch the results. Many thanks again Kevin!!!