Foundation.Modal.Hilbert.Basic

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structure LO.Modal.Hilbert.InferenceRule (α : Type u_2) :

Type u_2

instance of inference rule

antecedents : List (Formula α)
consequence : Formula α
antecedents_nonempty : self.antecedents ≠ []
Empty antecedent rule can be simply regarded as axiom rule. However, union of all these rules including to Hilbert.rules would be too complex for implementation and induction, so more than one antecedent is required.

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@[reducible, inline]

abbrev LO.Modal.Hilbert.InferenceRule.Necessitation {α : Type u_1} (φ : Formula α) :

InferenceRule α

Equations

LO.Modal.Hilbert.InferenceRule.Necessitation φ = { antecedents := [φ], consequence := □φ, antecedents_nonempty := ⋯ }

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@[reducible, inline]

abbrev LO.Modal.Hilbert.InferenceRule.Necessitation.set {α : Type u_1} :

Set (InferenceRule α)

Equations

⟮Nec⟯ = {x : LO.Modal.Hilbert.InferenceRule α | ∃ (φ : LO.Modal.Formula α), LO.Modal.Hilbert.InferenceRule.Necessitation φ = x}

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def LO.Modal.Hilbert.InferenceRule.«term⟮Nec⟯» :

Lean.ParserDescr

Equations

LO.Modal.Hilbert.InferenceRule.«term⟮Nec⟯» = Lean.ParserDescr.node `LO.Modal.Hilbert.InferenceRule.«term⟮Nec⟯» 1024 (Lean.ParserDescr.symbol "⟮Nec⟯")

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@[reducible, inline]

abbrev LO.Modal.Hilbert.InferenceRule.LoebRule {α : Type u_1} (φ : Formula α) :

InferenceRule α

Equations

LO.Modal.Hilbert.InferenceRule.LoebRule φ = { antecedents := [□φ ➝ φ], consequence := φ, antecedents_nonempty := ⋯ }

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@[reducible, inline]

abbrev LO.Modal.Hilbert.InferenceRule.LoebRule.set {α : Type u_1} :

Set (InferenceRule α)

Equations

⟮Loeb⟯ = {x : LO.Modal.Hilbert.InferenceRule α | ∃ (φ : LO.Modal.Formula α), LO.Modal.Hilbert.InferenceRule.LoebRule φ = x}

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def LO.Modal.Hilbert.InferenceRule.«term⟮Loeb⟯» :

Lean.ParserDescr

Equations

LO.Modal.Hilbert.InferenceRule.«term⟮Loeb⟯» = Lean.ParserDescr.node `LO.Modal.Hilbert.InferenceRule.«term⟮Loeb⟯» 1024 (Lean.ParserDescr.symbol "⟮Loeb⟯")

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@[reducible, inline]

abbrev LO.Modal.Hilbert.InferenceRule.HenkinRule {α : Type u_1} (φ : Formula α) :

InferenceRule α

Equations

LO.Modal.Hilbert.InferenceRule.HenkinRule φ = { antecedents := [□φ ⭤ φ], consequence := φ, antecedents_nonempty := ⋯ }

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@[reducible, inline]

abbrev LO.Modal.Hilbert.InferenceRule.HenkinRule.set {α : Type u_1} :

Set (InferenceRule α)

Equations

⟮Henkin⟯ = {x : LO.Modal.Hilbert.InferenceRule α | ∃ (φ : LO.Modal.Formula α), LO.Modal.Hilbert.InferenceRule.HenkinRule φ = x}

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def LO.Modal.Hilbert.InferenceRule.«term⟮Henkin⟯» :

Lean.ParserDescr

Equations

LO.Modal.Hilbert.InferenceRule.«term⟮Henkin⟯» = Lean.ParserDescr.node `LO.Modal.Hilbert.InferenceRule.«term⟮Henkin⟯» 1024 (Lean.ParserDescr.symbol "⟮Henkin⟯")

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structure LO.Modal.Hilbert (α : Type u_2) :

Type u_2

axioms : Theory α
rules : Set (InferenceRule α)

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inductive LO.Modal.Hilbert.Deduction {α : Type u_1} (H : Hilbert α) :

Formula α → Type u_1

maxm {α : Type u_1} {H : Hilbert α} {φ : Formula α} : φ ∈ H.axioms → H.Deduction φ
rule {α : Type u_1} {H : Hilbert α} {rl : InferenceRule α} : rl ∈ H.rules → ({φ : Formula α} → φ ∈ rl.antecedents → H.Deduction φ) → H.Deduction rl.consequence
mdp {α : Type u_1} {H : Hilbert α} {φ ψ : Formula α} : H.Deduction (φ ➝ ψ) → H.Deduction φ → H.Deduction ψ
imply₁ {α : Type u_1} {H : Hilbert α} (φ ψ : Formula α) : H.Deduction (Axioms.Imply₁ φ ψ)
imply₂ {α : Type u_1} {H : Hilbert α} (φ ψ χ : Formula α) : H.Deduction (Axioms.Imply₂ φ ψ χ)
ec {α : Type u_1} {H : Hilbert α} (φ ψ : Formula α) : H.Deduction (Axioms.ElimContra φ ψ)

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instance LO.Modal.Hilbert.Deduction.instSystemFormula {α : Type u_1} :

System (Formula α) (Hilbert α)

Equations

LO.Modal.Hilbert.Deduction.instSystemFormula = { Prf := LO.Modal.Hilbert.Deduction }

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instance LO.Modal.Hilbert.Deduction.instLukasiewiczFormula {α : Type u_1} {H : Hilbert α} :

System.Lukasiewicz H

Equations

LO.Modal.Hilbert.Deduction.instLukasiewiczFormula = LO.System.Lukasiewicz.mk

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instance LO.Modal.Hilbert.Deduction.instClassicalFormula {α : Type u_1} {H : Hilbert α} :

System.Classical H

Equations

LO.Modal.Hilbert.Deduction.instClassicalFormula = LO.System.Classical.mk

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instance LO.Modal.Hilbert.Deduction.instHasDiaDualityFormula {α : Type u_1} {H : Hilbert α} :

System.HasDiaDuality H

Equations

LO.Modal.Hilbert.Deduction.instHasDiaDualityFormula = inferInstance

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theorem LO.Modal.Hilbert.Deduction.maxm! {α : Type u_1} {H : Hilbert α} {φ : Formula α} (h : φ ∈ H.axioms) :

H ⊢! φ

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class LO.Modal.Hilbert.HasNecessitation {α : Type u_1} (H : Hilbert α) :

Prop

has_necessitation : ⟮Nec⟯ ⊆ H.rules

Instances

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instance LO.Modal.Hilbert.instNecessitationFormulaOfHasNecessitation {α : Type u_1} {H : Hilbert α} [H.HasNecessitation] :

System.Necessitation H

Equations

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

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class LO.Modal.Hilbert.HasLoebRule {α : Type u_1} (H : Hilbert α) :

Prop

has_loeb : ⟮Loeb⟯ ⊆ H.rules

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instance LO.Modal.Hilbert.instLoebRuleFormulaOfHasLoebRule {α : Type u_1} {H : Hilbert α} [H.HasLoebRule] :

System.LoebRule H

Equations

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

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class LO.Modal.Hilbert.HasHenkinRule {α : Type u_1} (H : Hilbert α) :

Prop

has_henkin : ⟮Henkin⟯ ⊆ H.rules

Instances

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instance LO.Modal.Hilbert.instHenkinRuleFormulaOfHasHenkinRule {α : Type u_1} {H : Hilbert α} [H.HasHenkinRule] :

System.HenkinRule H

Equations

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

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class LO.Modal.Hilbert.HasNecOnly {α : Type u_1} (H : Hilbert α) :

Prop

has_necessitation_only : H.rules = ⟮Nec⟯

Instances

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instance LO.Modal.Hilbert.instHasNecessitationOfHasNecOnly {α : Type u_1} {H : Hilbert α} [h : H.HasNecOnly] :

H.HasNecessitation

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class LO.Modal.Hilbert.HasAxiomK {α : Type u_1} (H : Hilbert α) :

Prop

has_axiomK : 𝗞 ⊆ H.axioms

Instances

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instance LO.Modal.Hilbert.instHasAxiomKFormulaOfHasAxiomK {α : Type u_1} {H : Hilbert α} [H.HasAxiomK] :

System.HasAxiomK H

Equations

LO.Modal.Hilbert.instHasAxiomKFormulaOfHasAxiomK = { K := fun (x x_1 : LO.Modal.Formula α) => LO.Modal.Hilbert.Deduction.maxm ⋯ }

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class LO.Modal.Hilbert.IsNormal {α : Type u_1} (H : Hilbert α) extends H.HasNecOnly, H.HasAxiomK :

Prop

has_necessitation_only : H.rules = ⟮Nec⟯
has_axiomK : 𝗞 ⊆ H.axioms

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instance LO.Modal.Hilbert.instKFormulaOfIsNormal {α : Type u_1} {H : Hilbert α} [H.IsNormal] :

System.K H

Equations

LO.Modal.Hilbert.instKFormulaOfIsNormal = LO.System.K.mk

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noncomputable def LO.Modal.Hilbert.Deduction.inducition! {α : Type u_1} {H : Hilbert α} {motive : (φ : Formula α) → H ⊢! φ → Sort u_2} (hRules : (r : InferenceRule α) → (hr : r ∈ H.rules) → (hant : ∀ {φ : Formula α}, φ ∈ r.antecedents → H ⊢! φ) → ({φ : Formula α} → (hp : φ ∈ r.antecedents) → motive φ ⋯) → motive r.consequence ⋯) (hMaxm : {φ : Formula α} → (h : φ ∈ H.axioms) → motive φ ⋯) (hMdp : {φ ψ : Formula α} → {hpq : H ⊢! φ ➝ ψ} → {hp : H ⊢! φ} → motive (φ ➝ ψ) hpq → motive φ hp → motive ψ ⋯) (hImply₁ : {φ ψ : Formula α} → motive (φ ➝ ψ ➝ φ) ⋯) (hImply₂ : {φ ψ χ : Formula α} → motive ((φ ➝ ψ ➝ χ) ➝ (φ ➝ ψ) ➝ φ ➝ χ) ⋯) (hElimContra : {φ ψ : Formula α} → motive (Axioms.ElimContra φ ψ) ⋯) {φ : Formula α} (d : H ⊢! φ) :

motive φ d

Equations

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

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noncomputable def LO.Modal.Hilbert.Deduction.inducition_with_necOnly! {α : Type u_1} {H : Hilbert α} [H.HasNecOnly] {motive : (φ : Formula α) → H ⊢! φ → Prop} (hMaxm : ∀ {φ : Formula α} (h : φ ∈ H.axioms), motive φ ⋯) (hMdp : ∀ {φ ψ : Formula α} {hpq : H ⊢! φ ➝ ψ} {hp : H ⊢! φ}, motive (φ ➝ ψ) hpq → motive φ hp → motive ψ ⋯) (hNec : ∀ {φ : Formula α} {hp : H ⊢! φ}, motive φ hp → motive (□φ) ⋯) (hImply₁ : ∀ {φ ψ : Formula α}, motive (φ ➝ ψ ➝ φ) ⋯) (hImply₂ : ∀ {φ ψ χ : Formula α}, motive ((φ ➝ ψ ➝ χ) ➝ (φ ➝ ψ) ➝ φ ➝ χ) ⋯) (hElimContra : ∀ {φ ψ : Formula α}, motive (Axioms.ElimContra φ ψ) ⋯) {φ : Formula α} (d : H ⊢! φ) :

motive φ d

Useful induction for normal modal logic.

Equations

⋯ = ⋯

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@[reducible, inline]

abbrev LO.Modal.Hilbert.theorems {α : Type u_1} (H : Hilbert α) :

Set (Formula α)

Equations

H.theorems = LO.System.theory H

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@[reducible, inline]

abbrev LO.Modal.Hilbert.Consistent {α : Type u_1} (H : Hilbert α) :

Prop

Equations

H.Consistent = LO.System.Consistent H

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theorem LO.Modal.Hilbert.normal_weakerThan_of_maxm {α : Type u_1} {H₁ H₂ : Hilbert α} [H₁.IsNormal] [H₂.IsNormal] (hMaxm : ∀ {φ : Formula α}, φ ∈ H₁.axioms → H₂ ⊢! φ) :

H₁ ≤ₛ H₂

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theorem LO.Modal.Hilbert.normal_weakerThan_of_subset {α : Type u_1} {H₁ H₂ : Hilbert α} [H₁.IsNormal] [H₂.IsNormal] (hSubset : H₁.axioms ⊆ H₂.axioms) :

H₁ ≤ₛ H₂