indexing description : "System's root class" date: "$Date$" revision: "$Revision$" class INTEGER_TEST create make feature -- Initialization make is -- Creation procedure. do x := 3 add_one end add_one is require x_positive: x >= 0 do x := x + 2 x := x - 2 ensure x_positive: x >= 0 x_increased: x = old x + 1 end x: INTEGER end -- class INTEGER_TEST