Type variables
gt(Vvar(_)) = {}
a type variable represents the set of all the (concrete) values which have any type, i.e., the empty set
(fresh) type variables are introduced in the abstract version of makefun
(wrong!) abstract operation
let rec makefun(ii,aa,r) = let d = newvar() in
let t = sem aa (bind(r,ii,d))) in
Mkarrow(d,t)
the problem
the evaluation of the function body should (possibly) lead to an instantiation of d
Previous slide
Next slide
Back to first slide
View graphic version