benjaminselfridge / logix Goto Github PK

quantifier precedence too high during parsing; need to make it extend as far to the right as possible

We want to be able to specify arbitrary connectives, not just and, or, etc. Same goes for quantifiers. The code doesn't do anything specific for the various connectives or quantifiers; that's all supplied by the definition for a Calculus.

Goal: generalize Calculus.hs, Parse.hs, and PPCalculus.hs to work with arbitrary connectives and quantifiers. This will mainly involve modifying Calculus.hs by replacing the different types of Formula and FormulaPat with general "Op" and "Quant" cases. These cases should probably have two Strings associated with them; one for an ASCII rendering of the quantifier, and one for an (optional) unicode rendering.

Module headers indicate GPL-3, but .cabal and LICENSE indicate BSD3.

We can now define arbitrary binary connectives, but there is currently no way to set the precedence of those connectives. Might actually be relatively easy (just sort the parsers based on a precedence tag).

Like SetPat, do MapPat which is like SetPat but every element of the set we are matching must match a pattern (rather than just wildcard). This would allow us to do things like !Gamma in linear logic rules

Add an additional field (maybe in the form of a tuple) to a formula to give it a name of some kind. This would allow us to display particular formulas in abbreviated form