Well, 2 things: first, I meant "currying". second, I found the answer: no. Under dynamic typing, the reduction steps are: (\a -> \b -> a) 1 2 (\b -> a) 2 -- the substitution don't occur right away (that would be lexical scope) a ?? "a" is not in the environment!! Sorry for the noise. PS: In a meta interpreter, lexical scope seems to be actually easier to implement than dynamic scope. 2009/4/26 Loup Vaillant :

Hi, can this code

(\a -> \b -> a) 1 2

eval to normal form in a strict language with dynamic scope?

Thanks, Loup

PS: some context:

I am currently implementing a toy language. The AST is this one:

data whnf = -- Weak Head Normal Form | Unit | Int of int | Bool of bool | Prim of (whnf -> whnf) -- curried | Fun of string * expr -- curried

data expr = | Whnf of whnf | Var of string | App of expr * expr | If of expr * expr * expr

Dynamic typing, dynamic scope, and, as you can see, functions have to be curried. I plan to implement lexical scope.