module Import>Basic>Num
import Import>Basic>List{Apply}

Add[left, right].
Add3[].
Add3_[].
//Should be shadowed.
Res[foo].

Add3[]: Add3_[]
Apply[f: Add3_[], x: #Number[]]: Add[left: x, right: 3]
Add[left: #Number[], right: #Number[]]: #Add[left, right]