At the top level of the standard library directory is the top level of "Zend /" additional library directories "ZendX /" and under this, all classes are stored in hierarchical structure.
Of the top level of the standard library directory "Zend /", the top-level directory "ZendX /" next to the additional libraries, in this subordinate, all classes are stored in a hierarchical structure.
At the top level of the standard library at the top level directory, add Zend /"、 Library Directory. You ZendX, all the classes are stored in a hierarchical structure.