Take the following schema (simplified) for element Type1 (1,10) being a
loop for elements A,B,C. Type 1 does not have an initiator so I need to
use a discriminator to establish the existence of an occurrence of Type1
so that incorrect backtracking does not occur after an error. Because
occursCountKind is 'implicit', the 1st occurrence is not a point of
uncertainty so the discriminator acts instead on any enclosing point of
uncertainty, but for 2nd and subsequent occurrences it acts on Type1. That
is all working as designed, but I think users will the 1st occurrence
behaviour a bit confusing. There are workarounds to avoid the problem, eg,
use occursCountKind 'parsed' or split Type1 into two as (1,1) and (0,9). I
think this is worth documenting in a tutorial as this is quite subtle
stuff.