Comparison of states now also compare the is_safe, legal and isP7
We can now create a graph simulator with a null proof
Added the beginning of the DSL language
DSL parser without the use of templates done
Added a function to compare two AbstractGlobalState
Not formula put parenthesis on the negated formula only when necessary
Added a function to splot proof models creating more global states

For a given function, it can happen that there exist multiple global
states for the proof model. The function
isIdenticalFunctionalDifferentProof allows to splot these cases.