This is an electronic edition of the 1980 notes distributed by Princeton University. The text was typed in T E X by Sheila Newbery, who also scanned the figures. Typos have been corrected (andâ€¦ (More)

This article was widely circulated as a preprint, about 12 years ago. At that time the Bulletin did not accept research announcements, and after a couple of attempts to publish it, I gave up, and theâ€¦ (More)

Our main theorem is that, if M is a closed hyperbolic 3â€“manifold which fibres over the circle with hyperbolic fibre S and pseudo-Anosov monodromy, then the lift of the inclusion of S in M toâ€¦ (More)

THE CENTRAL objects of study in this paper are collections {C,, . . . , C,} of g disjoint circles on a closed orientable surface M of genus g, whose complement M-(C, u . . . U C,) is a 2g-puncturedâ€¦ (More)

A collection of <italic>n</italic> balls in <italic>d</italic> dimensions forms a <italic>k</italic>-ply system if no point in the space is covered by more than <italic>k</italic> balls. We show thatâ€¦ (More)

This is an eprint approximation to [Thu86], which is the definitive form of this paper. This eprint is provided for convenience only; the theorem numbering of this version is different, and not allâ€¦ (More)

A rotation in a binary tree is a local restructuring that changes the tree into another tree. Rotations are useful in the design of tree-based data structures. The rotation distance between a pair ofâ€¦ (More)

The space of shapes of a polyhedron with given total angles less than 2Ï€ at each of its n vertices has a KÃ¤hler metric, locally isometric to complex hyperbolic space CH. The metric is not complete:â€¦ (More)

A derivation in a transformational system such as a graph grammar may be redundant in the sense that the exact order of the transformations may not &ed the final outcome; all that matters is thatâ€¦ (More)