The discussion centers around inserting subscripts in the app Diagrams.net, specifically for the notation ##f_{2,G_2}##. Users express difficulty in adding a subscript to ##G##, with initial suggestions indicating that subscripts to subscripts are not supported. A workaround is proposed by using the underscore "_" for subscripts. Additionally, users mention the option of using LaTeX for mathematical typesetting by selecting "Extras" and then "Mathematical typesetting," which allows for proper formatting of expressions like \(f_{2,G_2}\). The conversation highlights the importance of exploring app features to find solutions.