Hardy's "A course of Pure Mathematics" has been highly regarded since it was first published in 1908 because it was an innovative text: rigorous, modern, well-written. Its intended readership was always first year "honours" mathematics students. This book inspired innovation in subsequent generations of textbook writers.
However, in the 21st century, this book really can no longer be recommended for its original teaching purpose. As a textbook it is outdated (a term I hate, but it is true). It is now an historical curiosity - although one which I am pleased to own, and the exercises in the book are still worth a look.
Calculus teaching has progressed considerably since 1908. The construction of the real number system in Hardy's book, using the Dedekind Cut method is overly complicated - the use of the of Least Upper Bound is much simpler and clearer. Hardy defines the concept of integral solely as the anti-derivative; there is no discussion of Riemann sums, or Darboux sums, etc. I am sure I would not want to take Hardy's approach today.
I think we are better off recommending books are more modern.
I will start by recommending "Calculus" by Michael Spivak.
Apart from the Tk and Expect extensions, one of the best parts of Tcl its general extensibility through the Tcl C API. Unfortunately, this is one of Tcl's less well-documented features. Most books and online tutorials either ignore it completely or, at best, provide perfunctory discussion and examples.
The other poorly documented feature is the objected-programming framework which was belatedly added after Tcl fell out of the mainstream of programming languages and so languishes unused.
The biggest problem of all is that that there is no online forum for Tcl users now that Google has dropped Groups. Usenet comp.lang.tcl was the main discussion forum and it is now gone.
Your claim that Russia influenced Brexit, which the Cameron-led Conservative government opposed, has been thoroughly debunked, as has the Trump-Russia collusion hoax in the US. Indeed, a certain Guardian "journalist", who promoted the Brexit-Russia influence hoax, lost a defamation case against her for falsely promoting it. The UK, which is currently governed by a Conservative party majority parliament, has also been, from the start, one of the most aggressive and dependable supporters of Ukraine in her struggle to resist the Russian invasion. So, I am wondering, to what kind of "significant influence" are you alluding?
https://www.theage.com.au/national/victoria/hundreds-of-deli...