(TLC) A variety of
lambda-calculus in which every
term is labelled with a
type.
A
function application (A B) is only synctactically valid if
A has type s --> t, where the type of B is s (or an
instance
or s in a
polymorphic language) and t is any type.
If the types allowed for terms are restricted, e.g. to
Hindley-Milner types then no term may be applied to itself,
thus avoiding one kind of non-terminating evaluation.
Most
functional programming languages, e.g.
Haskell,
ML,
are closely based on variants of the typed lambda-calculus.