Title Incremental Inference of Partial Types Authors Mario Coppo, UNiversita' di Torino Daniel Hirschkoff, ENS Lyon Main Fields 7. design of algorithms 9. foundations of functional programming 21. type theory Other Main Fields Abstract + Keywords We present a type inference procedure for \emph{partial types} for a $\lambda$--calculus equipped with datatypes. Our procedure handles a type languages containing greatest and lesser types ($\omega$ and $\bot$ respectively), subtyping, and datatypes (yielding constants at the level of terms). The main feature of our algorithm is \emph{incrementality}; this allows us to progressively analyse successive term definitions, which is of interest in the setting of a system like the \textit{CuCh machine} (cuurently being developped at the University of Rome). The methods we describe have led to an implemention; we illustrate its use on a few examples. Ke words: type inference, partial type, functional languages