I had a paper accepted in a workshop that only publishes its proceedings on its website; one of these workshops that tell you that submitting to the workshop does not prevent you from submitting elsewhere. The paper proposed a new method A, and applied it to problems B and C.
Now, I want to write a conference version of the paper. The conference version will present method A, apply it to problems B and C with extended experiments, and additionally to problem D.
How do I refer/cite the method A in the conference paper? Does the workshop count at all? In my field (CS), I have been told that the workshops do not count. Yet, it feels wrong to call it a novel method. Is the method A contribution of the conference paper or not?