I have a problem with the definite article 'the' in following sentence from Wikipedia:
Some of the namespaces may or may not be officially considered part of the BCL by Microsoft, but all are included as part of the libraries that are provided with Microsoft's implementation of the .NET Framework.
(BCL: Base Class Library)
Firstly, the sentence starts with 'Some of the namespaces', which is correct, because there are many namespaces and the author refers to a group of those namespaces. Next, 'part of the BCL by Microsoft': here is my problem. There is only one BCL, so 'the' is not indicating any specific member of a group. Secondly, just as 'the BCL', there is only one 'Microsoft', but it doesn't have 'the'. So how is this sentence correct?
My definition of 'the' has two parts. First, indication of a group and second, referring to a specific member in that group. For example, 'the teacher in school was pretty'. Here, school has many teachers and we refer to a specific teacher.