[Crm-sig] ADDITION: property "active in period"

[Vladimir Alexiev]

I propose to add a new property "active in period" with range E4 Period.
The domain should include E39 Actor and E41 Appellation, so I think should be E77 Persistent Item.
If it's judged that such property cannot be defined meaningfully for E77, then could be split to two proeperties for E39 and E41.

Reasons:

1. E39 Actor: BM has a field "period of activity of the actor".
We currently model this as "was present at" a "fake" Event, but P12 doesn't quite say what we need:
  <person-institution/144526> P12i_was_present_at <person-institution/144526/activity/1>;
  <person-institution/144526/activity/1>P4_has_time-span <person-institution/144526/activity/1/date>.
  <person-institution/144526/activity/1/date> P82a_begin_of_the_begin "1859"; P82b_end_of_the_end "1900".

2. E41 Appellation: BM tracks temporal validity of person names.

- One solution is described in email "ISSUE: P37, P38, P48 should be moved up to Appellation":
<person/name> a E82_Actor_Appellation;
  P37i_was_assigned_by <person/name/assigned>;
  P38i_was_deassigned_by <person/name/deassigned>.
<person/name/assigned> a E15_Appellation_Assignment; 
  P4_has_time-span <person/name/assigned/date>.
<person/name/assigned/date> a E52_Time-Span;
  P82_at_some_time_within "1600".
<person/name/deassigned> a E15_Appellation_Assignment; 
  P4_has_time-span <person/name/deassigned/date>.
<person/name/deassigned/date> a E52_Time-Span;
  P82_at_some_time_within "1850".

- But "active in period" would be a much better solution, since it also allows you to specify the cultural period through which the name was used:
<person/name> a E82_Actor_Appellation;
  P200_active_in_period <period/medieval-france>.
<period/medieval-france> a E4_Period;
  P3_has_note "Medieval France";
  P7_took_place_at <place/France>;
  P4_has_time-span <period/medieval-france/dates>.
<period/medieval-france/dates>
  P82a_begin_of_the_begin "1100"; 
  P82b_end_of_the_end "1650".