A Cuntz--Krieger uniqueness theorem for semigraph $C^*$-algebras
  Higher rank semigraph algebras are introduced by mixing concepts of ultragraph algebras and higher rank graph algebras. This yields a kind of higher rank generalisation of ultragraph algebras. We prove Cuntz--Krieger uniqueness theorems for cancelling semigraph algebras and aperiodic full semigraph algebras. 
Bernhard Burgstaller
math.OA