型推論に関する最近の話題への雑感 ref: https://qiita.com/kmizu/items/2ace816340e8553bd278

file0.txt

fun fold_left f [] z = z  
  | fold_left f (x::xs) z = fold_left f xs (f z x);
val fold_left = fn : ('a -> 'b -> 'a) -> 'b list -> 'a -> 'a

file1.java

var x = expression;