@conference {122, title = {Modular Semantics for Transition System Specifications with Negative Premises}, booktitle = {CONCUR 2013 {\textendash} Concurrency Theory}, series = {Lecture Notes in Computer Science}, volume = {8052}, year = {2013}, pages = {46-60}, publisher = {Springer}, organization = {Springer}, author = {Martin Churchill and Peter D. Mosses and Mohammad Reza Mousavi} }