In one of the earliest publications on fingerprinting, Wagner defines “perfect fingerprinting” to include schemes such that any alteration to the marked object that makes the fingerprint unrecognizable must necessarily make the object unusable. Several modern fingerprinting schemes are based on the assumption that perfect fingerprinting of digital information is possible. This paper explores th...

Logical characterizations of the common prior assumption (CPA) are investigated. Two approaches are considered. The first is called frame distinguishability, and is similar in spirit to the approaches considered in the economics literature. Results similar to those obtained in the economics literature are proved here as well, namely, that we can distinguish finite spaces that satisfy the CPA fr...

1. The axiom of choice. The object of this paper is to consider the possibUity of setting up a logic in which the axiom of choice is false. The way of approach is through the second ordinal class, in connection with which there appear certain alternatives to the axiom of choice. But these alternatives have consequences not only with regard to the second ordinal class but also with regard to oth...

The assumption of linearity is tested using five statistical tests for the US and the Canadian unemployment rates. An AR(p) model was used to remove any linear structure from the series. Strong evidence in favour of non−linearity was found in the case of Canada. The result for the US is not so clear cut. The author would like to thank Chung−Ming Kuan, David Chappell, Chris Martin and Costas Mil...