R code to recreate the example in Section 5 of "Prestress behaviour and ductility requirements in structures: solutions from a unified algebraic approach"

This file contains the R code that has been used to the construction of the model of the Frame, to solve all the problems, and to draw all the figures of these solutions, as presented in Section 5. The file was extracted from the original *.Rnw file that contains both the LaTeX and the R code that generates the entire paper.