Added File forgotten with last Commit

Discussion of the Join Precosheaf

Removed a somewhat vague Statement

Added Citations to recent Research

Added citations to both, the recent paper by
de Silva, Munch, and Stefanou and our poster.

More thorough Treatment of -D-Categories

A more thorough (not perfect) treatment of -D-categories.

Fixed Typo

Fixed Mistake in second Example for Join Trees

Adjusted 'build-script', Metadata, Subrepostates

Now using YAML Structure File

Added Yaml File describing Structure

Integrated Images into 'build-script'

Switch to Python 3

Some Formulas on their own Line

Reformulations

Reformulations

Reformulations

Renamed extended Pers.-Enhancement to complete ...

Better Exposition of Proofs

Proof of Compatibility Lemma

Some Parts rewritten