MODULE mod_1
  TYPE,ABSTRACT:: abstract_type
     INTEGER:: i
   CONTAINS
  END TYPE abstract_type
  TYPE,EXTENDS(abstract_type):: extended_type
     INTEGER:: j
   CONTAINS
  END TYPE extended_type
CONTAINS
  SUBROUTINE f2(t)
    CLASS(abstract_type),POINTER,intent(in)::t
    PRINT*,"f2 executed"
  END SUBROUTINE f2
END MODULE mod_1
! Main program
PROGRAM MAIN
  USE mod_1
  IMPLICIT NONE
  class(extended_type),POINTER::t
  CALL f2(t)
END PROGRAM MAIN