Hello,
i'll be glad to work on your project.
I'm a software architect and i have a MASTER in Complex Software Engeneering.
UML diagrams are in the center of my studies and my abilities, so i'm really at ease with Unified Languages.
I'll provide you 3 clean use cases diagrams with all the comments needed and OCL constraints to ensure that there is no ambiguous reasonning, i'll also provide as many revisions as you want.
i work on ArgoUML or starUML but i have no problems to discover new modeling software.
Have a nice day.