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

def foo := fun (A B : ★) (x : A) (y : B) => x;
def bar := [A B : ★][x : A][y : B] x;

----------

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