On 4/19/08, Gareth McCaughan <gareth.mccaughan@pobox.com> wrote:
... (Plodding pedestrian solution follows. I have no computer algebra system worth the name, but this isn't really hard enough to require one.) ...
Hm. Perhaps Richard will call me to heel if I'm jumping to conclusions: Chao & Sun apparently managed to stretch this into a 5-page paper. Funnily enough, the worldly mathematician who first introduced (also in the early sixties) to my tender young mind the shocking concept of a paper factory was also Chinese. The abysmally non-PC hypothesis suggests itself that our oriental colleagues might have been ahead of the pack, at least in this respect. [Come to think of it, I could have done without them inventing fireworks as well ...] Anyhow, impressively wrangled, Gareth! Fred Lunnon