How can I type Wick contraction equations in MS word?

Question

I do not use LaTeX, so I want to know is there some methods that I can type the following equations using MS word: equations like this:

Answer 1

There are LaTeX add-ins for some versions of MS Word.

However, if an add-in does not work in Office 365, edit the document in free, open source, LibreOffice Writer, which can use the (also free) TexMaths extension for LaTeX. "LaTeX equations can be inserted as images (SVG or PNG formats) and the LaTeX code is saved into the image attribute for further editing."

Documents can be created, opened, edited and saved in a number of formats, including DOCX, using LibreOffice Writer, as shown in the Save dialog below.