Root families: category-changing morphology

[Mar97]

A root family records the word forms a single (sub-morphemic) root projects across lexical categories — the [Mar97] uncategorised-roots pattern: the category of the surface word is determined by the morphological environment, not by the root itself.

Main declarations

• Morphology.LexCat — theory-neutral lexical category of a word form.
• Morphology.RootFamily — a root label with its category-stamped forms.

Consumers: Studies/Panagiotidis2015.lean (categoriser theory + the English root-family sample), Studies/McNallyDeSwart2011.lean (AdjEntry.toRootFamily adapter for Dutch adjective entries).

inductive Morphology.LexCat : Type

The lexical category of a word form (theory-neutral).

• noun : LexCat
• verb : LexCat
• adjective : LexCat

@[implicit_reducible]

instance Morphology.instReprLexCat : Repr LexCat

Equations

• Morphology.instReprLexCat = { reprPrec := Morphology.instReprLexCat.repr }

def Morphology.instReprLexCat.repr : LexCat → Nat → Std.Format

Equations

• Morphology.instReprLexCat.repr Morphology.LexCat.noun prec✝ = Repr.addAppParen (Std.Format.nest (if prec✝ ≥ 1024 then 1 else 2) (Std.Format.text "Morphology.LexCat.noun")).group prec✝
• Morphology.instReprLexCat.repr Morphology.LexCat.verb prec✝ = Repr.addAppParen (Std.Format.nest (if prec✝ ≥ 1024 then 1 else 2) (Std.Format.text "Morphology.LexCat.verb")).group prec✝
• Morphology.instReprLexCat.repr Morphology.LexCat.adjective prec✝ = Repr.addAppParen (Std.Format.nest (if prec✝ ≥ 1024 then 1 else 2) (Std.Format.text "Morphology.LexCat.adjective")).group prec✝

@[implicit_reducible]

instance Morphology.instDecidableEqLexCat : DecidableEq LexCat

Equations

• Morphology.instDecidableEqLexCat x✝ y✝ = if h : x✝.ctorIdx = y✝.ctorIdx then isTrue ⋯ else isFalse ⋯

structure Morphology.RootFamily : Type

A root family: a set of word forms derived from a common root, each appearing in a different lexical category.

• rootLabel : String

  Label for the root (approximate; roots are sub-morphemic)

• forms : List (String × LexCat)

  Word forms and their categories

def Morphology.instReprRootFamily.repr : RootFamily → Nat → Std.Format

Equations

• One or more equations did not get rendered due to their size.

@[implicit_reducible]

instance Morphology.instReprRootFamily : Repr RootFamily

Equations

• Morphology.instReprRootFamily = { reprPrec := Morphology.instReprRootFamily.repr }

def Morphology.RootFamily.hasCategory (rf : RootFamily) (c : LexCat) : Bool

Does this root family have a form in the given category?

Equations

• rf.hasCategory c = rf.forms.any fun (x : String × Morphology.LexCat) => x.snd == c