Status of This Memo This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited. Abstract This document describes several problems that have been identified with the Session Initiation Protocol's (SIP) non-INVITE transaction.

The structure of the three pattern classes defined by the sets of forbidden permutations {2143, 4321}, {2143, 4312} and {1324, 4312} is determined using the machinery of monotone grid classes. This allows the permutations in these classes to be described in terms of simple diagrams and regular languages and, using this, the rational generating functions which enumerate these classes are determi...

We show analytically and numerically that the generation of long-lasting soliton oscillations in resonant chi(2) optical materials possesses a threshold for the amplitude of a fundamental wave. The persistent oscillations of solitary waves reported by Etrich et al. [Phys. Rev. E 54, 4321 (1996)] are found to appear for finite values of the wave amplitude.

For a sample of ten nearby barred galaxies, images at 6.75μm and 15μm of circumnuclear starbursts are being taken by ISOCAM on board of the ISO satellite. We first recall the main goals of our project, give its current status, and finally, as an example, preliminary results for NGC 4321 (M100) are presented.

The structure of three pattern classes Av(2143, 4321), Av(2143, 4312) and Av(1324, 4312) is determined using the machinery of monotone grid classes. This allows the permutations in these classes to be described in terms of simple diagrams and regular languages and, using this, the rational generating functions which enumerate these classes are determined.

We show that permutations avoiding both of the (classical) patterns 4321 and 3241 have algebraic generating function conjectured by Vladimir Kruchinin.