I want to define some constraints for my profile. For example I need a constraint for a stereotype of the metaclass "connector". I want to define that these element must have one source like the oclkindof(source) and one target like the oclkindof(target). I found some texts by using the Google search engine like http://modeling-languages.com/wp-content/uploads/2012/03/OCLChapter.pdf or http://www.omg.org/spec/OCL/2.0/ and other slides and papers but not the right description of OCL for me.
Best regards