Terminating a running workflow on a document set when a document within is changed?

Hi there, 

So I have a document set workflow that runs only on 'content type = Document Set'. I'm building a second workflow for the documents therin that is intended to monitor for changes within the document set. It's intent is to stop the running workflow on the document set itself if a document is altered in anyway. 

I know that i can learn which document set the document is from via some regex and some itemURLS, but is there an easy way to terminate the document set workflow from a separate workflow?

Thanks a bunch for your time!