# . : ->

[rd at sanger.ac.uk]

> 
> i rather like the proposal
> 
> 
> FOO f
> tag a b
> tag c d tag3 e
> 
> where tag3 is in a submodel, then
> 
>   ee = ff.tag[2][tag3]
> 
> i have to get used to it, but i think it is natural
> 
> and if i want what is right of c i would have to do it
> as a constraint WHERE tag[1]=c, i suppose ?
> 

No, "WHERE tag[1] = c" will not work.  There is nothing tying that to
the ee line.  You need

  FROM
    cc = ff.tag, 
    ee = cc[1][tag3]
  WHERE
    cc = c

This binds cc to match c, and hence ee only ranges over things right of that.