[RIF] Core comments/questions

Section 2.3 says that functions can't be arguments in positional atomic 
formulas, and that non-external functions are not allowed in equalities. 
But it doesn't say that functions are disallowed in frame formulas and in 
membership formulas (later sections imply that).  I think the restriction 
is that non-external functions are not allowed anywhere, and external 
functions are allowed only in equality  and nowhere else, is this right?

Section 2.3 indicates that membership is allowed in rule conclusions (by 
not saying that isn't, as is said for equalitiy), but an editor's note and 
the EBNF say it isn't allowed in rule conclusions. Which of these is the 
current design?  (I saw the note that the design may change in this area).

Stella