==================
Lambda Abstraction
==================

def foo := fun (A : *) (x : A) => x;

----------

(program
  (definition
    (identifier)
    (expr
      (app_term
        (labs
          (param_block
            (identifier)
            (expr
              (app_term
                (app
                  (term
                    (star))))))
          (param_block
            (identifier)
            (expr
              (app_term
                (app
                  (term
                    (identifier))))))
          (expr
            (app_term
              (app
                (term
                  (identifier))))))))))