41. Therefore, ? ? is a symplectic vector field if and only if ? is a closed form . 42. For most geometric stable distributions, the probability density function and cumulative distribution function have no closed form . 43. That is, if ? and ? are closed forms , and one can find some ? such that 44. These findings provide excellent insight to the shape range ( especially closed forms ) of Mycenaean pottery. 45. For simple rational numbers, the closed form expression is often in terms of less complicated special functions. 46. First, that f ( \ Omega ) is a closed form follows from the next two lemmas: 47. This can always be done in closed form since this is a case of simple linear regression. 48. The idea of de Rham cohomology is to classify the different types of closed forms on a manifold. 49. In some cases there is no single equation in closed form that is equivalent to the parametric equations. 50. The Fisher information matrix for estimating the parameters of a multivariate normal distribution has a closed form expression.