Type inference fails for generic types

[pschachte]

For example, this code compiles:

def reverse1(lst:list(T)):list(T) =
    reverse1(lst, [])

def reverse1(lst:list(T),
        rest:list(T)):list(T) =
    if {lst = [?h|?t] ::
            reverse1(t, [h|rest])
       | else         :: rest
    }

but not if the type annotations on the recursive helper function are omitted.