TermProject patterns simplify projection of sub-terms. A strategy application inside a match pattern selects the corresponding sub-term and applies s to it. For example, instead of writing
A : Typed(Var(x),_) -> x
it is now possible to write
A = ?Typed(Var(),_)
This feature can also be used to perform tests on subterm in a
match pattern, e.g., the pattern
?[x | ]
binds the head of a list to =x=, checks that the tail is not empty and produces the tail as
result.