Changelog

Version 1.3 — 2025-08-14

Added

• decision procedures for SPL (strictly piecewise-local)
• join-semigroups and join-monoids
  • syntacticJSemigroup and syntacticSemilattice to compute them
  • a new Porter, LTK.Porters.SyntacticSemilattice to display them
  • isJoinVariety and isMJoinVariety for arbitrary membership queries
  • :isJVarietyS and :isJVarietyM in plebby
  • :isJVarietyT is the natural extension to tiers of :isJVarietyS
• LTK.FSA.renameSymbolsByMonotonic is now exported
• classify synonyms to match plebby but retain compatibility:
  • "1" is now also "Trivial" from :isTrivial
  • "Fin" is now also "Finite" from :isFinite
• classify now accepts "Dot1" and "SPL"

Changed

• improved some documentation inside plebby
• fixed one of the examples
• LTK.Porters.Pleb was redesigned in terms of recursive schemes
• moved optimization level from language-toolkit.cabal to cabal.project

Removed

• The Ord instance for FSA was a dangerous lie, it is now gone.

Version 1.2.0.1 — 2024-04-27

Changed

• PLEB: fixed @@ ("Domination") operator
• reenabled -O2 compilation

Version 1.2 — 2024-04-16

Added

• commonPrefix and commonSuffix functions on automata
• isDot1 (dot depth at most one)
• syntacticSemigroup (interfacing with finite-semigroups)
• syntacticOMonoid, syntacticOSemigroup (ordered monoid or semigroup)
• isVarietyS (ordered varities from finite-semigroups)
• plebby:
  • new, more detailed :help system
  • strict order (.∙.(x,y) asserts start of x precedes start of y)
  • Ctrl+C interrupts handled, abort current computation

Changed

• algebraic tools split and expanded in a new package (finite-semigroups)
• plebby:
  • inequalities supported in :isVarietyM/S/T for order
  • better error messages
  • bugfix: two-expression commands no longer break on "it"
• many classification tasks now use semigroups from finite-semigroups
• bugfix: trimUnreachables handles epsilon-edges and avoids recomputation

Version 1.1 — 2023-06-18

Added

• preliminary French translation of manual pages
• basic Emacs mode for syntax highlighting
• classification procedures
  • isAcom (aperiodic and commutative)
  • isLAcom (locally isAcom)
  • isFO2BF (two-variable FO with betweenness of factors)
  • isVariety (Plebby has one command each for *, +, and tier)
  • isMTF, isMTDef, isMTRDef, isMTGD (simple multitier classes)
• Porters
  • egg-box diagrams
  • graphs of syntactic orders
• Pleb syntax
  • empty variadics
  • reversal (⇄)
  • upward closures (↑, or loopify in the library)
  • shuffle products (⧢ or autShuffle in the library)
  • symbol neutralization (|syms|, or neutralize in the library)
  • nonempty iteration (+e equivalent to @(e,*e))
• Plebby commands
  • :cequal and :cimplies to account for the semantics
  • :eggbox (display the egg-box)
  • :synord (display syntactic order)
• Plebby configuration file

Changed

• bugfix: omega function works in properly regular semigroups
• performance enhancement: faster FO2(S) test
• performance enhancement: faster (co)finite test
• performance enhancement: faster SP test

Version 1.0.1 — 2022-03-28

Changed

• fixed a mistest in classify, as well as a severe performance issue

Version 1.0 (initial hackage release) — 2022-03-15

Added

• classify command
• LTK.Algebra module and new decision procedures LTK.Decide.*
  • B
  • CB
  • Definite, (T)(R)Def restrictions on suffixes or prefixes (on tiers)
  • Finite
  • FO2, FO2S, FO2B: definable in two-variable FO with <, (<,+1), (<,bet)
  • GD: generalized definite, prefixes AND suffixes
  • GLPT: generalization of LPT
  • GLT: generalization of LT
  • LPT: locally J-trivial, contains combinations of piecewise-local factors
  • TLPT: tier-based LPT
  • Trivial: accepts ALL strings, or NO strings
  • associated :isCLASS plebby commands
• LTK.DecideM: classify monoids, to avoid recomputation
• left- and right-quotients in LTK.FSA and in PLEB
• union and intersection of symbol sets wherever they may appear in PLEB
• downward closure in PLEB
• :Jmin plebby command for displaying a graph of J-classes

Changed

• dotify now uses AT&T format instead of Jeff format
• factorize now uses AT&T format instead of Jeff format
• improved AT&T import and export

Removed

• stress-specific symbols in LTK.Factors

Version 0.3 — 2020-09-16

Added

• AT&T import and export LTK.Porters.ATT
• prefix-tree import from corpus LTK.Porters.Corpus
• string-extension learners LTK.Learn.*
• more plebby commands
  • AT&T import and export :readATT, :readATTO, :writeATT
  • learners :learnSL, :learnSP, :learnTSL

Changed

• extraction is now a submodule: LTK.Extract.SL not LTK.ExtractSL, etc

Version 0.2 — 2019-09-01

Added

• more decision algorithms LTK.Decide.*
  • LT: locally testable, defined by sets of k-substrings
  • LTT: locally threshold-testable, FO[+1]
  • PT: piecewise-testable, defined by sets of k-subsequences
  • SF: star-free, aperiodic, star-height zero
  • SL: the decider formerly in LTK.ExtractSL
  • SP: the decider formerly in LTK.ExtractSP
  • TLT: tier-based LT
  • TLTT: tier-based LTT
  • TSL: tier-based strictly local

Changed

• factor extraction is now LTK.Extract.*

Version 0.1 — 2019-08-23

• moved to a Cabal-based installation format
• removed several exploratory files
• add computations over tiers

Version 0.01a — 2018-12-20

• initial full public release