Denys Fisher sale in Schofields department store in Leeds in 1965. A year later, Fisher licensed Spirograph to Kenner Products in the United States. In 1967 Spirograph was chosen as the UK Toy of the Year. Denys Fisher Toys, which also produced other toys and board games, was sold to Palitoy in 1970 and it was subsequently bought by Hasbro. Through the 1980s & 1990s Fisher continued to work with Hasbro in developing new toys and refining Spirograph. Denys Fisher Toys produced the following toys and games: Denys Fisher Denys Fisher (11 May 1918 – 17 September 2002) was an English engineer
Cone of curves "cone of curves" of formula_1 to be where the formula_6 are irreducible, reduced, proper curves on formula_1, and formula_18 their classes in formula_13. It is not difficult to see that formula_20 is indeed a convex cone in the sense of convex geometry. One useful application of the notion of the cone of curves is the Kleiman condition, which says that a (Cartier) divisor formula_11 on a complete variety formula_1 is ample if and only if formula_23 for any nonzero element formula_24 in formula_25, the closure of the cone of curves in the usual real topology. (In general, formula_20 need not