...intervals of applying algebra to the second book of Euclid, we experimented with circles; we stuck bamboos into the parched earth, measured their shadows...us his paper crystal; and when I asked him how he had managed to make it, he merely smiled and said it had been so easy. I looked at Elizabeth and laughed....

...and he_i in (5.124). Compare this result with (5.123). Chapter 6 MULTILEVELS AND DOMAIN DECOMPOSITION Sometimes for fun, we cut and folded sheets of paper so as to make cubes and pyramids. Aldous Huxley It is quite a three-pipe problem. Sir Arthur Conan Doyle 6.1 Introduction Effective preconditioning...