Cumulative Effects of Concurrent Actions on Numeric-Valued Fluents

                           Esra Erdem
                Vienna University of Technology

			Alfredo Gabaldon
		    National ICT Australia


We propose a situation calculus formalization of action domains that 
include numeric-valued fluents (so-called additive or measure 
fluents) and concurrency. Our approach allows formalizing concurrent 
actions whose effect s increment/decrement the value of additive 
fluents. For describing indirect effects, we employ mathematical 
equations in a manner that is inspired by recent work on causality 
and structural equations.