Tetractys, a poetic form invented by Ray Stebbing, consists of at least 5 lines of 1, 2, 3, 4, 10 syllables (total of 20). Tetractys can be written with more than one verse, but must follow suit with an inverted syllable count. Tetractys can also be reversed and written 10, 4, 3, 2, 1.
“Euclid, the mathematician of classical times, considered the number series 1, 2, 3, 4 to have mystical significance because its sum is 10, so he dignified it with a name of its own – Tetractys. The tetractys could be Britain’s answer to the haiku. Its challenge is to express a complete thought, profound or comic, witty or wise, within the narrow compass of twenty syllables.” – Ray Stebbing