# Dependence Relation Types

## Data dependence - a mapping from an output name of one unit of computation to an input name of a set of other units of computation. The sequential analog is mapping of actual parameters to formal parameters.

## Shared name dependence - a set of names to which access is shared among a set of units of computation and a specification of the mode of access to each name by each unit of computation.

## Control dependence - a mapping, either one-to-n or n-to-one, of activation to units of computation. The analog for sequential programs is transfer of control from one statement to another.

## Demand dependence - a matched pair of control/data dependence pairs. The analog for sequential languages is a function call. Control is transferred along with parameters and control and parameters must return.