similar to  I have the "WHEN CONCRETE block is never concrete" warning:
However, unlike the issue with the calculator example I created my own binary operation which copies all elements from a PlusExpression (find the language in ). Nevertheless I seem to be unable to get rid of this warning. Users are very confused by this message and therefore I would really love to get rid of it.
All my tries with the typesystem did not work and the error persists. I eventually extended the calculator example with a binary operation (MyPlusExpression):
Here the typesystem tells me I cannot apply this operator to int-int (due to the typeof_InputFieldReference rule) - however if my MyPlusExpressin extends the PlusExpression everything is fine?
What am I doing wrong here? Surely there is some further checks I am unable to find? Do I have to give my binary operation a special typesystem rule to work correctly?
Any help appreciated! Thanks!