include "lambda/background/preamble.ma".
+include "lambda/notation/functions/variablereferencebyindex_2.ma".
+include "lambda/notation/functions/abstraction_2.ma".
+include "lambda/notation/functions/application_3.ma".
+
(* SUBSETS OF SUBTERMS ******************************************************)
(* Policy: boolean marks metavariables: b,c