Abstract: One of the prominent mathematical features of natural language is the prevalence of “upward” and “downward” inferences involving determiners and other functional expressions. These inferences are associated with negative and positive polarity positions in syntax, and they also feature in computer implementations of textual entailment. Formal treatments of these phenomena began in the 1980’s and have been refined and expanded in the last 10 years. This paper takes a large step in the area by extending typed lambda calculus to the ordered setting. Not only does this provide a formal tool for reasoning about upward and downward inferences in natural language, it also applies to the analysis of monotonicity arguments in mathematics more generally.