Syntactic equality check

[Broes De Cat]

In for example the idp-application paper, it was important that we manually replaced identical terms with the same (new) variable: ! t x y : arc(label(t,x),label(t,y)) <- edge(t,x,y) & label(t,x) < label(t,y). ! t x y : arc(label(t,x),label(t,y)) <- edge(t,y,x) & label(t,x) < label(t,y). die we oplosten door het zelf te flatten:

! t x y lx ly : arc(lx,ly) <- lx=label(t,x) & ly=label(t,y) & edge(t,x,y) & label(t,x) < label(t,y). ! t x y lx ly : arc(lx,ly) <- lx=label(t,x) & ly=label(t,y) & edge(t,y,x) & label(t,x) < label(t,y).

We should add at least a syntactic equality check for terms and handle term more efficiently.

[Broes De Cat]

This can be implemented with a transformation recently written for function detection.