Questions about the etymology model

Hi John,
I have three questions about the etymology module.
Question 1
Is the  etymology  object type, as a child of  entry , necessary? It seems like it s just a container for a list of etymons (and multi-etymons, and etym descriptions). If it s just a container for things, then why not get rid of it and attach those things to  entry  directly? That s how we do it elsewhere in the standard, for example, we don t have a container for senses, we attach each sense directly as a child of entry.
The only reason why  etymology  might be necessary is if you want to make it possible for dictionary authors to have more than one in a single entry, where eaxch  etymology  object would represent a different hypothesis about the headword s etymology. If this is how you meant it, then fine, but maybe we should say so in the text.
Question 2
Why is  etymon  allowed to have more than one  etymDate , that is, more than one  from-until  timespan? If an etymon represents one step in the etymological evolution of the headword, then I would imagine that the step lasted for exactly one timespan, not several.
Question 3
Etymons can be grouped into multi-etymons (the  multiEtymon  object type) to indicate that the headword was derived by combining two etymons. That s fine and makes sense. But then the object model as you have designed it would allow for each etymon inside a multi-etymon to have different timespans (because time is assigned to etymons, not to multi-etymons). This seems unsafe to me, it fails to prohibit a contradiction.
I would propose an alternative object model where we distinguish between  timespans  and  etymons . The etymology of a headword would be a list of timespans, and each timespan would have one or more etymons, where the intended semantics is that if it has more than one, then the etymons were compounded to form the headword:
- entry
- etymology
- timespan (from: ... until: ...)
- etymon: ...
- timespan (from: ... until: ...)
- etymon: ...
- timespan (from: ... until: ...)
- etymon: ...
- etymon: ...