Secure methods of payment are needed before we will see widespread commercial use of the Internet. Recently proposed and implemented payment methods follow one of three models: electronic currency, creditdebit, and secure credit card transactions. Such payment services have di erent strengths and weaknesses with respect to the requirements of of security, reliability, scalability, anonymity, ac...

It has been known for six years that the restriction of Girard’s polymorphic system F to atomic universal instantiations interprets the full fragment of the intuitionistic propositional calculus. We firstly observe that Tait’s method of “convertibility” applies quite naturally to the proof of strong normalization of the restricted Girard system. We then show that each β-reduction step of the fu...

Pretreatment of rice husk by the Alkaline Peroxide Assisted Wet Air Oxidation (APAWAO) approach enhanced the enzymatic convertibility of cellulose in APAWAO-pretreated rice husk. The present work describes the structural changes in rice husk brought about by APAWAO pretreatment by means of Scanning Electron Microscopy (SEM). The SEM images illustrate the extensive loss of biomass integrity foll...

Secure methods of payment are needed before we will see widespread commercial use of the Internet. Recently proposed and implemented payment methods follow one of three models: electronic currency, credit-debit, and secure credit card transactions. Such payment services have diierent strengths and weaknesses with respect to the requirements of of security, reliability , scalability, anonymity, ...

We show that a version of Martin-Löf type theory with extensional identity, a unit type N1,Σ,Π, and a base type is a free category with families (supporting these type formers) both in a 1and a 2-categorical sense. It follows that the underlying category of contexts is a free locally cartesian closed category in a 2-categorical sense because of a previously proved biequivalence. We then show th...

In a general equilibrium model with risk neutral and risk averse agents, we show that if banks issue both demand deposits and equity, then free banking is run-proof and ecient. In particular, we obtain the ®rst best insurance solution if there is adequate risk neutral capital. If sucient risk neutral capital is unavailable, then a partial suspension of convertibility is optimal. In general, t...

The paper uses a dual-currency search theoretic approach to demonstrate that it is possible to induce the acceptance of a local currency in a dollarized economy. In the model, we assume that a foreign currency is in full circulation and the government policy tool is the convertibility of the local currency to the foreign currency. We show that the economy can achieve equilibria where two monies...

A fundamental result in rewriting is : E |= s ≈ t ⇐⇒1 E ` s = t ⇐⇒2 s↔E t 1. is Birkhoff’s theorem expressing that semantic consequence (|=) coincides with syntactic consequence (`). 2. expresses that equality in equational logic (=) coincides with convertibility in rewriting (↔∗), a property known as logicality. We show that the result can be extended to hold for several sub-equational logics ...