I did the first section of Markus's tutorial
using MPS 2.0 EAP and came across a minor problem.
I'm not sure if I missed something, but the editor allows me to create an abstract concept if I create an "Entity," then hit control-space and select the only completion (EntityAttribute.)
I thought that smart references shouldn't allow this. I verified the cardinality of EntityAttribute is set to 1.
Is this an MPS bug?