This might help you understand! Since the LOA93 pay rate provision ends after Dec. 31, 2009, what pay rate provision is in effect on Jan. 1, 2010? The answer to that question is found in the underlying provisions of the agreement that preceded LOA93. That of course is LOA84. LOA84 is the contract that was in effect regarding pay rates when LOA93 was made effective. Therefore, LOA93 modified and changed LOA84 to the extent is was explicit on the term. Just like LOA 84 modified the first concessionary agreement in mid-2002 and the first concessionary agreement modified the basic agreement that was effective in 1998. According to the explicit pay rate term of LOA93, the pay rate provision of LOA84 was changed on the effective date of LOA93. Also, according to its explicit time of effectiveness, the LOA93 pay rates provision expires after Dec 31, 2009, leaving in its place the provisions of LOA84 for that date and beyond.