Water is an essential yet constrained commodity for human communities and ecological systems depend on it. With population growth and economic development, water resource is increasingly declining. Over the past two decades, because of changes in population and climate, and relative welfare increase, the per capita consumption of water has increased. Thus, optimal use of available water resourc...

The relation between corn yield and the number of acres in corn on Iowa farms isa matter of considerable interest. If technical and economic conditions were uniform, the presumption wouldbe that corn acreage wouldvary with the productive capacity of the soil. The very existence of different type-of-farming areas in the state, however, indicates non-uniform conditions. The questions arise as to ...

Cats are nice. (: : :) because cats never overlap. Abstract In this paper we discuss two approaches to adverbial quantiication, the so-called`bound variable approach' and thèsituation-based approach', and we address the suggestion that has been made in the literature that the latter reduces to the former as soon as the underlying structure of situations has been characterized at the required le...

In this paper we describe how a combination of the classical “universal” E-unification and “rigid” Eunification, called “mixed” E-unification, can be used to efficiently handle equality in universal formula semantic tableaux, that are an extension of free variable tableaux.

Van Lambalgen (1990) proposed a translation from a language containing a generalized quantifier Q into a first-order language enriched with a family of predicates Rs, for every arity i (or an infinitary predicate R) which takes Qz~(z, yl, . . . , y,~) to Vz(R(z, yl,..., g,~) --" ~b(x, Yl,..., Y,~)) (gl . . . . . g~ are precisely the free variables of Qzq~). The logic of Q (without ordinary quan...

We present a sound, complete, modular and lean labelled tableau calculus for many propositional modal logics where the labels contain \free" and \universal" variables. Our \lean" Prolog implementation is not only surprisingly short, but compares favourably with other considerably more complex implementations for modal deduction.

In this paper, we present a further liberalization of the-rule in free variable semantic tableaux. It is eeective in that (1) it is both a natural and intuitive liberalization, and (2) can reduce the proof size non elementarily as compared to previous versions of the-rule.