In this section, I review prominent formalisms, focusing mainly on two recent proposals using the notion of comprehension syntax due to Peter Buneman et al. [1] with extensions to support arrays--a data structure of prime importance for an language with mathematical programming capabilities such as OPL. The first is due to Leonidas Fegaras and David Maier [9] and uses the notion of Monoid Comprehensions; the second is due to Leonid Libkin, Rona Machlin, and Limsoon Wong [14] and proposes a functional calculus of array objects. These two formalisms are very similar, differing mostly in their treatment of arrays (as collections in [9], and as functions in [14]). My intention is to try and merge ideas from both for our purpose.