Syntax rules would require a regress outside the system leading to a variation of Godel's incompleteness theorem. The rules would have to be self referencing, and a context within context observes this. The framework would have to be descriptive by nature. As self referencing it would be subject to double positives and double negatives simultaneously. Its truth value lies in is descriptive properties.
For example:
(-True) --> (-True)
(True) --> (True)
((True)True)--->(True & -True)
((-True)-True) --> (True & -True)