Haiku a phrase in the remaining 12 "on" (it may not be apparent from the English translation of the Issa that the first five "on" mean "Edo's rain"). In comparison with English verse typically characterized by syllabic meter, Japanese verse counts sound units known as ""on"" or morae. Traditional haiku consist of 17 "on", in three phrases of five, seven and five "on" respectively. Among contemporary poems "teikei" ( fixed form) haiku continue to use the 5-7-5 pattern while "jiyuritsu" ( free form) haiku do not. One of the examples below illustrates that traditional haiku masters were not always constrained by
Invariant of a binary form for the ring of covariants. showed that the ring of invariants of a degree 8 form is generated by 9 invariants of degrees 2, 3, 4, 5, 6, 7, 8, 9, 10, and the ring of covariants is generated by 69 covariants. August von Gall () and confirmed the generators for the ring of invariants and showed that the ideal of relations between them is generated by elements of degrees 16, 17, 18, 19, 20. showed that the algebra of invariants of a degree 9 form is generated by 92 invariants. Cröni, Hagedorn, and Brouwer computed 476 covariants, and Lercier