Re: Scratch low-level abstract syntax

> Component((String)shortName,
>           (ImplDependent)functionality,
>           (Set of String)inputPorts,
>           (Set of String)outputPorts,
>           (Set of String)parameters)

I think there should be nothing implementation dependant here; the
definition of a component should be standard across implementations.

> Pipeline((Set of Component)components,
>          (Set of String)parameters,
>          (Set of Step)steps,
>          (Set of Pipes)pipes,
>          (InputPort)input?,
>          (OutputPort)output?)

In http://www.cogsci.ed.ac.uk/~richard/pipeline.html I did this somewhat
differently.  Pipelines are a subtype of component, so they have input
and output ports just as components do, and there are pipes linking the
pipeline inputs to the inputs of contained components.

Also, the components field is redundant, since it is just the set of
components of the steps, and I don't see the point of putting redundant
features in an abstract syntax.

-- Richard