Circumfixal Exponence

Circumfixal exponence wraps a stem with morphological material on both sides (prefix + suffix). This is a theory-neutral description of the surface pattern — how a circumfix arises (head movement in DM, readjustment rules in other frameworks) is left to theory-specific modules.

Cross-linguistically attested circumfixes include:

• German past participle ge-...-t (ge-mach-t)
• Tigrinya negative ʔay-...-n (ʔay-stem-n)
• Malay ke-...-an (ke-baik-an "goodness")

Connections

• Core/MorphRule.lean: AttachmentSide.circumfix — morphological classification
• DM/Fission.lean: Distributed Morphology operations (theory-specific derivation)

structure Morphology.Circumfix.CircumfixExponence : Type

Circumfixal exponence: a stem is wrapped by a prefix and suffix.

This is a surface-level description of the morphological pattern, neutral between theories of how the circumfix arises (head movement, readjustment, templatic morphology, etc.).

For example, German past participle ge-mach-t:

• prefix_ = "ge-"
• suffix_ = "-t"
• stem = "mach"

• prefix_ : String

  Morphological material before the stem

• suffix_ : String

  Morphological material after the stem

• stem : String

  The verbal stem that gets wrapped

• gloss : String

  Description of the source of the circumfix

def Morphology.Circumfix.instReprCircumfixExponence.repr : CircumfixExponence → Nat → Std.Format

Equations

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instance Morphology.Circumfix.instReprCircumfixExponence : Repr CircumfixExponence

Equations

• Morphology.Circumfix.instReprCircumfixExponence = { reprPrec := Morphology.Circumfix.instReprCircumfixExponence.repr }

instance Morphology.Circumfix.instDecidableEqCircumfixExponence : DecidableEq CircumfixExponence

Equations

• Morphology.Circumfix.instDecidableEqCircumfixExponence = Morphology.Circumfix.instDecidableEqCircumfixExponence.decEq

def Morphology.Circumfix.instDecidableEqCircumfixExponence.decEq (x✝ x✝¹ : CircumfixExponence) : Decidable (x✝ = x✝¹)

Equations

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

def Morphology.Circumfix.instBEqCircumfixExponence.beq : CircumfixExponence → CircumfixExponence → Bool

Equations

• One or more equations did not get rendered due to their size.
• Morphology.Circumfix.instBEqCircumfixExponence.beq x✝¹ x✝ = false

instance Morphology.Circumfix.instBEqCircumfixExponence : BEq CircumfixExponence

Equations

• Morphology.Circumfix.instBEqCircumfixExponence = { beq := Morphology.Circumfix.instBEqCircumfixExponence.beq }

def Morphology.Circumfix.CircumfixExponence.realize (c : CircumfixExponence) : String

Apply circumfixal exponence to produce the surface form.

Equations

• c.realize = c.prefix_ ++ c.stem ++ c.suffix_

def Morphology.Circumfix.CircumfixExponence.isDiscontinuous (_c : CircumfixExponence) : Bool

A circumfix is discontinuous: its exponents are separated by the stem.

Equations

• _c.isDiscontinuous = true

def Morphology.Circumfix.CircumfixExponence.attachmentSide (_c : CircumfixExponence) : Core.Morphology.AttachmentSide

The attachment side of a circumfix is AttachmentSide.circumfix.

Equations

• _c.attachmentSide = Core.Morphology.AttachmentSide.circumfix

theorem Morphology.Circumfix.circumfix_attachment (c : CircumfixExponence) : c.attachmentSide = Core.Morphology.AttachmentSide.circumfix

Every circumfix has the correct attachment side.

theorem Morphology.Circumfix.circumfix_discontinuous (c : CircumfixExponence) : c.isDiscontinuous = true

Every circumfix is discontinuous.

theorem Morphology.Circumfix.circumfix_realize_concat (c : CircumfixExponence) : c.realize = c.prefix_ ++ c.stem ++ c.suffix_

The surface form of a circumfix is prefix + stem + suffix.

def Morphology.Circumfix.germanPastParticiple (stem : String) : CircumfixExponence

German past participle ge-...-t.

Equations

• Morphology.Circumfix.germanPastParticiple stem = { prefix_ := "ge-", suffix_ := "-t", stem := stem, gloss := "PTCP" }

theorem Morphology.Circumfix.german_pp_example : (germanPastParticiple "mach").realize = "ge-mach-t"

German past participle surfaces correctly.