Influence

• often (but not always) corresponds to link in an 'influence diagram'

• captures the idea that something affects something else

• formally, represents the fact that one term is used in the calculation of another (i.e. appears on the right-hand-side of the function used to calculate the other)

• can start from a compartment, flow or variable

• can go to a flow or a variable (not to a compartment, except to for initialisation)