IMPURE MATHEMATICS Once upon a time (l/t) pretty little Polly Nomial was strolling across a field of vectors when she came to the boundary of a singularly large matrix. Now Polly was convergent, and her mother had made it an absolute condition that she must never enter such an array without her brackets on. Polly, however, was feeling particularly badly behaved and ignored this condition on the basis that it was insufficient, and made her way amongst the complex elements. Rows and columns closed in on her from all sides. Tangents approached her surface. She became tensor and tensor. Quite suddenly, two branches of a hyperbola touched her at a single point. She oscilated violently, lost all sense of directrix and went completely divergent. She tripped over a square root, and plunged headlong down a steep gradient. When she rounded off once more, she found herself inverted, apparently alone, in a non-Euclidean field. (Would you believe space?) She was being watchers however. That smooth operator, Curly Pi, was lurking inner product. As his eyes devoured her curvilinear coordinates, a singular expression crossed his face. He wondered, "Was she still convergent?" He decided to integrate improperly at once. Hearing a common fraction behind her, Polly rotated and saw Curly Pi approaching with his power series extrapolated. She could see at once by his degenerate conic and his dissipative terms that he was bent on no good. "Arcsinh!" she gasped. "Hoho," he said. "What a symmetric little asymptote you have. I can see that your angles have a lot of secs." "Oh, sir," she protested, "keep away from me. I haven't got my brackets on. "Calm yourself, my dear," said our suave operator, "your fears are purely imaginary. What order are you?" "Seventeen," replied Polly. Curly leered, "I suppose you've never been operated on." "Of course not," replied Polly quite proudly, "I'm completely convergent." "Come,come," said Curly. "Let's go on to a decimal place I know and I'll take you to the limit." "Never!" gasped Polly. "Abscissa!" he swore, using the bilest oath he knew. His patience was gone. Coshing her over the coefficient with a log until she was powerless, Curly removed her discontinuities. He stared at her significant places and be began smoothing her points of inflection. She felt his hand tending to her asymptotic limit. Her convergence would soon be gone forever. There was no mercy because Curly was a heavyside operator. Curly's radius squared itself: Polly's loci quivered. He integrated by parts. He integrated by partial fractions. The complex beast even went all the way around and did a contour integration. What an indignity--to be multiply connected on her first integration! Curly went right on operating until he had sgisfied her hypotheses. When Polly got home that night, her mother noticed that she was no longer continuous but had been truncated in several places. But it was too late to differentiate now. As the months went by, Polly's denominator increased monotonically. Finally, she went to the L'Hospital and generated a small but pathological function. The moral of our sad story is this: If you want to keep your convergence, never allow a single degree of freedom. Auntie Derivative. Rated x^2 No one under 360 degrees admitted.