identity is the minimum while
    2-identity is not big enough to do the job we want to do.

HC: I have fallen a bit behind on this thread while attending to some other 
    matters, but in this reply, you do seem to me to be coming around to an 
    understanding of the issues involved, as I see them.  You put the matter
    this way, &quot;We don't need 3-identity because we have 4-identity, 5-identity, 
    6-identity, ..., in the 'standard predicate calculus'&quot;.  Actually, as I think 
    you must k