We present an algorithm that computes the structure of a finite abelian group G from a generating system M . The algorithm executes O(|M | √ |G|) group operations and stores O( √ |G|) group elements.

In this paper we examine the cardinal structure of inner models that satisfy GCH but do not contain 0. We show, assuming that 0 exists, that such models necessarily contain Mahlo cardinals of high order, but without further assumptions need not contain a cardinal κ which is κ-Mahlo. The principal tools are the Covering Theorem for L and the technique of reverse Easton iteration. Let I denote th...

In coalitional games with side payments, the core predicts which coalitions form and how benefits are shared. The predictions however run into difficulties if the core is empty or if some coalitions benefit from not blocking truthfully. These difficulties are analyzed in games in which an a priori given collection of coalitions can form, as the collection of pairs of buyer-seller in an assignme...

We examine the mechanism design problem for a single buyer to procure purchase-options for a homogeneous good when that buyer is required to satisfy an unknown future demand. Suppliers have 2dimensional types in the form of commitment costs and production costs. The efficient schedule of options depends on the distribution of demand. To implement an efficient outcome, we introduce a class of me...

In inrestigations o f the neural processes und¢rlytng tarious behavioural phenomena, it is often rerj di~icult to separate cause from effect, especially when the part of the nervous system central to this control is distant from both ¢h ~. sensory and the motor ends of :his behariour. Orercoming fheye di~eu_t~fas. Edmund Roi:~, with his colleagues, has carried out a series of rery elegant exper...