1. A computer-implemented method for checking parameter access including: accepting, by a computer system, a specification of an ordering constraint for a plurality of tasks, in which at least some of the tasks are not ordered relative to one another; for each of one or more parameters, identifying, by the computer system, the tasks that access those parameters; and checking, by the computer system, for potential conflict in the access to the parameters by the identified tasks according to the specification of the ordering constraint, including determining scopes of instances of one of the parameters, determining whether a plurality of the scopes include a task that references the parameter, and identifying the referenced parameter as an ambiguous parameter if a plurality of the scopes include the task that references the parameter.