Electronic institutions are a formalism to define and analyse protocols among agents with a view to achieving global and individual goals. In this paper we elaborate on the verification of properties of electronic institutions based on the dialogues that agents may hold. Specifically, we provide a computational approach to assess whether an electronic institution is normatively consistent. In this manner, given an electronic institution we can determine whether its norms prevent normcompliant executions from happening. For this we strongly rely on the analysis of the dialogues that may occur as agents interact by exchanging illocutions in an electronic institution. 1.

Abstract. We propose a logic-based rendition of electronic institutions – these are means to specify open agent organisations. We employ a simple notation based on first-order logic and set theory to represent an expressive class of electronic institutions. We also provide a formal semantics for our constructs and present a distributed implementation of a platform to enact electronic institutions specified in our formalism. 1

Abstract. We present an algebraic treatment of exception handlers and, more generally, introduce handlers for other computational effects representable by an algebraic theory. These include nondeterminism, interactive input/output, concurrency, state, time, and their combinations; in all cases the computation monad is the free-model monad of the theory. Each such handler corresponds to a model of the theory for the effects at hand. The handling construct, which applies a handler to a computation, is based on the one introduced by Benton and Kennedy, and is interpreted using the homomorphism induced by the universal property of the free model. This general construct can be used to describe previously unrelated concepts from both theory and practice. 1

Some physical aspects related to the limit operations of the Thomson lamp are discussed. Regardless of the formally unbounded and even infinite number of “steps” involved, the physical limit has an operational meaning in agreement with the Abel sums of infinite series. The formal analogies to accelerated (hyper-) computers and the recursion theoretic diagonal methods are discussed. As quantum information is not bound by the mutually exclusive states of classical bits, it allows a consistent representation of fixed point states of the diagonal operator. In an effort to reconstruct the self-contradictory feature of diagonalization, a generalized diagonal method allowing no quantum fixed points is proposed.

As quantum parallelism allows the effective co-representation of classical mutually exclusive states, the diagonalization method of classical recursion theory has to be modified. Quantum diagonalization involves unitary operators whose eigenvalues are different from one.