[F]ractions with a defining relation are nothing but linear orthogonal arrays or their translates.

If the subproblems are still too complex to grasp easily, these in turn can be decomposed into subsubproblems. This process of successive problem analysis and decomposition can be illustrated by using a problem tree structure.

Pythagoras, she suggests, venerated three-sided figures for their vaginal symbolism; Upper Palaeolithic dips in rock are chipped away by cavemen into vulval icons.

Pause by some neglected graveyard, / For a while to muse, and ponder / On a half-effaced inscription, / Written with little skill of song-craft, / Homely phrases, but each letter / Full of hope, and yet of heart-break, / Full of all the tender pathos / Of the Here and Hereafter;— / Stay and read this rude inscription, / Read this Song of Hiawatha!