November 4, 2020
      
                  
        
  Author(s)
  Spencer  Breiner,   Olivier  Marie Rose,   Blake S. Pollard,   Eswaran  Subrahmanian
 
       
            
    
    
        This paper applies operads and functorial semantics to address the problem of failure diagnosis in complex systems. We start with a concrete example, developing a hierarchical interaction model for the Length Scale Interferometer, a high-precision