do you mean three ?
Yes, you can count better than me! Nice catch. That is what we in the biz call “copypasta” from my original design that indeed had four primitives. We can fix that.
@ahmed.abuali Please read the revised and new content on the Workflows documentation page and let me know what you think (you may need to force refresh to clear browser cache). I added much more detail about the “schema” of the workflow spec and the logic behind how you construct a general workflow.
On that note, it would be fantastic if a daring soul among the @ce-alpha-testers or @devs would attempt to craft the the complex workflow sketched in the docs into a successful workflow spec. “It is left as an exercise for the reader…” is a cute joke for physicists but slightly inappropriate for a software product manual 
There is an example of the ‘complex’ workflow in the Neutron Star Examples 
Hello @andrew.manning @mrpelicer @jakinh @jjahan ,
Could you please add Brian Kyanjo PostDoc at Georgia Tech in Computing to the reviewers/testers list for the alpha release? His email is bkyanjo3@gatech.edu. He is willing to test any Module as soon as possible.
Thank you!