scryer-prolog VS egglog

thank you! the scryer community deserves much of the credit too. everyone is welcome and encouraged to join us at https://github.com/mthom/scryer-prolog! some exciting plans in the pipe

Djot is the markup syntax that is used for the documentation of Scryer Prolog, using a parser written in Prolog:

https://github.com/aarroyoc/djota

It works well so far. One of the few limitations I noticed so far pertains to the formatting of tables. For instance, consider the table used in library(format) to describe control sequences:

https://github.com/mthom/scryer-prolog/blob/b0566e41503a6c8d...

It contains several entries that span multiple lines, yet are meant to denote only a single row of the table, such as:

    % | `~Nr`    |  where N is an integer between 2 and 36: format the            |

There's a nice book[1][2] about Prolog, with modern characteristics. Moreover, there are things like ProbLog[3] and DeepProbLog[4] that allow you to use probabilistic reasoning and power of machine learning. I am personally looking forward for Scryer Prolog[5] to achieve its goals.

[1] https://www.metalevel.at/prolog

[2] https://github.com/triska/the-power-of-prolog

[3] https://github.com/ML-KULeuven/problog

[4] https://github.com/ML-KULeuven/deepproblog

[5] https://github.com/mthom/scryer-prolog

One use case would be for example Scryer-prolog. The latter is a very fast and easy to use Prolog. It includes high performance constraint solving (e.g. CLP(ℤ)). I'd write a bridge to this prolog, but not if it is too cumbersome.

if native Prolog, which one? scryer-prolog seems to be constantly mentioned a having fast string support and useful libraries for dealing with JSON and web APIs

No, what I'm describing is the "monadic" behaviour of `phrase_from_file/2` and similar predicates. In conjunction with definite clause grammars, this means that your I/O operations either conform to the provided spec or fail. This is a "hot topic" (if LP topics can really still be "hot") and sees active development in new prolog systems.

Check this out:

https://www.swi-prolog.org/pldoc/man?section=pio

https://github.com/mthom/scryer-prolog/blob/084fc845902f7b43...

The herbie project using egraphs to explore different ways of rewriting floating point expressions. https://herbie.uwplse.org/ One can also write custom rulesets in egglog (a new egraph rewriting system / language / datalog) https://egraphs-good.github.io/egglog/?example=herbie

The approach is not yet anywhere near being able to touch all the domains sympy can handle. Destructive term rewriting tends to be a bit more forgiving to unsoundness in the rules and still returning roughly meaningful results. EGraph rewriting (and other automated reasoning systems) tend to just return junk as soon as you aren't careful about your semantics. Associativity and commutativity are ubiquitous in CAS applications and encoding these concepts in general purpose terms is rather unsatisfying. The post above emphasizes specialty methods for polynomials, which it would be desirable to find a clean way to integrate into egraph techniques. Variable binding (which is treated in a rather mangled form in CAS systems) is seemingly important for treating summation, differentiation, and integration correctly. The status of doing variable binding efficiently and correctly in egraphs is also unclear imo.

For semantic analyzers, check out egg and egglog. They're custom data structures for representing compiler rewrite rules in a non-destructive way.

The recent work on relational, datalog-inspired egraphs in PLDI this year ("Unifying Datalog and Equality Saturation") is actually interesting because it can solve cases like the y/x*x -> y identity example, by the power of an interval analysis on x (among other things.) Sort of like adding a postulate but instead it's by adding relations between terms in the graph.

https://github.com/egraphs-good/egglog

https://arxiv.org/pdf/2304.04332.pdf

Close, but the link is on Page 13, and it points here: https://github.com/mwillsey/egg-smol

Unfortunately the naming is all a bit confusing, isn't it....