Paged Out! #4 is out and once again I got to write two articles. This time, my articles are about TypeScript's type system. The first article appears on page 37 and shows a program which only compiles if an array in the source code is a valid magic square. The second article, on page 31 is a continuation and looks at a useful use-case of TypeScript's advance type-system. Enjoy! All the other articles are great, do read the ezine from cover to cover!| Alok Menghrajani