A Second Easter: A Celebration of Presence

sermon text; MS Word document

Black-robes, or, Sketches of missions and ministers in the wilderness and on the border.

http://www.archive.org/details/blackrobesorsket00nevirich

Type Reconstruction in the Presence of Polymorphic Recursion and the Recursive Types

We establish the equivalence of type reconstruction with polymorphic recursion and recursive types is equivalent to regular semi-unification which proves the undecidability of the corresponding type reconstruction problem. We also establish the equivalence of type reconstruction with polymorphic recursion and positive recursive types to a special case of regular semi-unification which we call positive regular semi-unification. The decidability of positive regular semi-unification is an open problem.