hello list,
here's a small question:
let a be a polymorphic variant type of the form  ([`C1 of t1 | `C2 of t2 |
.. | `Cn of tn] as 'a)
let b be a polymorphic variant type of the form ([`C1 of t1['b/'a] | `C2 of
t2['b/'a] | ... | `Cn of tn['b/'a] | Cp of tp] as 'b)
where ['b/'a] represents substitution. In other words, b has one more
constructor than a. Is a always a subtype of b?
--Jacques L.