The Swift File Format is entirely text based. It is designed so that equation can be easily written by hand. This document explains the Swift File Format First of all you should understand about the inherent nature of an equation.
Every equation is an equation inside an equation inside an equation.
Basically what this means is that suppose we have the equation . You can see below how it is internally saved and the actual equation file. So the file format logically follows this pattern. For some tags, a type follows the tag. The type number is the number of the icon on the sub toolbar with numbers starting at 1.