It is very desirable to have a uniform use of such symbols throughout the hypermanual. At the same time, different parts of the hypermanual are certainly going to need their specialized symbols as well. This may be achieved by having a common set of general-purpose symbols, together with various extensions (supersets of symbols) which serve the specialized purposes.
The symbols used in Volume 1 of "Features and Fluents" may be a starting-point for discussion. A first proposal for a common general set is available in tabular form in [notation/general]. The superset required for the specifics of the Features and fluents approach (underlying semantics, assessment of entailment methods) is found in tabular form in [notationn=fafnot].