Happily, the Internet does suggest newsagents "Honey's of the High" - handily across the road from Univ, and once home to a budget-priced photocopier where I'd churn out college music society fliers etc. - is still going.

Rule 57 is an unfortunate error and should be disregarded

I didn't know the Philips machine but I remember Viewdata/Teletext graphics showing the floods sweeping chunkily across the Kingdom in the game on the BBC Micro Welcome pack: youtu.be/RSE1NVaUs8s?...

Also on that theme - Lockhart's "Mathematician's Lament" on teaching mathematics as exploration & curiosity rather than crushing rote - building on his essay (profkeithdevlin.org/wp-content/u...). I like both: Polya focuses more on applicable methods, while Lockhart is perhaps the more motivational.

Polya's "How To Solve It" has related method under generic name "Variation Of The Problem": reduce it to a simple/degenerate case with known answer, to identify characteristics of general solution. E.g. for volume of a pyramid frustum, set the top to zero (pyramid!) or to match the bottom (prism!)

I don't know a name for it but remember using it ("a length isn't stated, but the multiple-choice options show it's got to cancel out - so let's assume a value which makes it easy"). Perhaps "solution by pedagogical convention" or "solution by implied existence, uniqueness, and generality"? ;-)

Yes, I since worked out the unit square and agree. Now I'll have to think about a nudging a vertex! :-)

(An example of the latter, on theatrical angel investors: "The term should really be confined to those who help with no thought of a benefit in return, as the rules of angelic behaviour would seem to dictate... They nearly always lose their money anyway and become angels by default.")

Interesting! It's a weaker condition than convexity (where *every* point on the segment would be in A). If 0 and 1 are in S then so is every point of the form k/(2^n) in (0, 1). Now... if the corners of a unit square are in S, what does that force to be included? Now I'm curiously wondering too! :-)

But I suppose with the classic Dragon book, if you didn't have Pascal on your computer you might have implemented a Pascal compiler yourself before using it to write your game. In (so, so much!) theory. ;-)

I wondered how popular Pascal was in mid-1980s to sell a book on programming adventures. (I'd *heard* of Pascal, and local library had "Pascal from BASIC", but in UK home computing at the time I don't ever remember *seeing* it. However, I learn from Wikipedia it was popular on Apple.)