Stem higraph$ (all stems)
2 papers:
FoSSaCS-2003-PowerT #abstraction #reasoning- Abstraction in Reasoning about Higraph-Based Systems (JP, KT), pp. 392–408.
CSL-2001-PowerT #algebra- An Algebraic Foundation for Higraphs (JP, KT), pp. 145–159.
FoSSaCS-2003-PowerT #abstraction #reasoning
CSL-2001-PowerT #algebra