Haiku in English four lines (sometimes known as "haiqua") or longer have been written, some of them "vertical haiku" with only a word or two per line. These poems mimic the vertical printed form of Japanese haiku. The translator Nobuyuki Yuasa considered four lines more appropriate in his translations, being closest to the natural conversational rhythm of the colloquial language of haiku, also that three lines did not carry the weight of hokku and found it impossible to use 'three lines' consistently for his translations. The contemporary poet John Martone has written a vast number of vertical haiku. Haiku have also appeared in
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