SlotCorrespondence

Relates to #49 (closed).

Already showed this to @MerleBeaujon . @thvg Curious to hear your thoughts!

Please use this MR for discussion of technical details and further change requests. For more general discussion on whether this is the right approach, let's keep that in the related issue.

I reworked :FrameMapping to :SlotCorrespondence to accomplish the following:

• We can express correspondences between slots of fact frames
• We can express correspondences between slots of more than two frames
  • This was already possible, just that it was restricted by Act and Fact type

I demonstrate these changes on the library example. I also made minor changes to the interpretation of the library example, specifically to the preconditions of the suspend_member act. The new interpretation is in my opinion less redundant, and also allows a demonstration of fact-to-fact slot correspondences.

Added

• :SlotCorrespondence is the main object describing relations between slots
• :SlotReference describes a slot that is part of a SlotCorrespondence.
  • It has properties :slotFromFrame and :slotLabel to describe the slot being referenced

Removed

• :FrameMapping and most of its baggage: :hasActFrame, :hasFactFrame, :hasActSlot, :hasFactSlot.
• :hasFrameMapping; correspondence are now expressed stand-alone, with no direct link needed to the Act or ContextualizedFacts involved.

Changed

• The library example .ttl and diagram