Re: Scope of step types

> > The step and pipeline types visible in a pipeline or library are:
> 
> Oops, I missed a case,

And another case (I realise we may not be following this plan, but I want
to get it stated correctly):

> >  - the standard built-in types;
> >  - any implementation-provided types;
> >  - the types visible in any library that is imported;
>  - the pipelines that are imported;
> >  - the step types declared in the pipeline or library;
- for a pipeline in a library, the types visible in the containing library
> >  - for a pipeline, the pipeline itself;
> >  - for a library, any pipelines defined in it.

-- Richard