There are hedges that may bring about that against which they seek to guard their drafters.
Among these, one has to count this.
The European Investment Bank, which is making loans to various Greek businesses (in order to fulfill a commitment to issue a total of 600 million euros of such loans by January 2013, and 1.4 billion euros by the end of 2015) has taken to including clauses that account for the possibility that Greece will resume use of the drachma.
As I mentioned in mid February of this year, the EIB is one party in a “troika” of institutions bargaining on behalf of the central Eurozone countries with the countries of the zone’s more troubled periphery. The EU itself and the IMF are the other members of said troika.