I am trying to create a language which has types such as Any, String, Number etc. I created the concepts AnyType, StringType, NumberType. Now I would like to create typing rules, such as "type of node foo is StringType" or "StingType is subtype of AnyType". However, I cannot enter equations, such as "typeOf(node) :==: <StringType>". The auto completion menu does not offer me any of the types or concepts in my language, only stuff from BaseLanguage. How can I reference my types and concepts from type expression language?
P.S. the MPS itself is quite cool. :-)