Hi, please take a look at the problem we are suppose to tackle, Pg. 429 3 (ii).
There is no production (left hand side) for Y, in X - > YZ and Z - > XY ...
Am I missing something? or is this okay??? surely Y must have a production??
Oh, well I managed to complete the question, the question in my first post above was not an issue in any of the steps I applied.
So I think it is ok, don't stress about it like i did.