Typically, the courts intervene when there is a dispute between congress and the executive branch over

Typically, the courts intervene when there is a dispute between Congress and the executive branch over: c. the interpretation of a law

Most of the disputes happened because of how they think they should interpret the law. Some of them think that they should interpret it exactly as it was written, while the others think that they should interpret it from the indirect meaning within that law.

Currently, as of february 2016, an american traveling in france would be by the exchange rate. the weakness of the euro and the strength of the us dollar means that items in france cost less to an american than they otherwise would. of course, if this trend reverses and the us dollar weakens and the euro strengthens, such as was happening in early 2008, an american traveling in france would have an adverse experience because items would cost relatively more.