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Diff — Sequent calculus

Revision #1558 → #2185 · back to history

modifiedSequent calculus33c87c64147a
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteMathlib has no formalization of sequent calculus as a proof system; ModelTheory only covers first-order syntax and semantics, not deduction systems.
statusnot_formalized
modifiedHilbert stylebb294320cef0
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteNo Hilbert-style deduction system is defined in Mathlib.
statusnot_formalized
modifiedGentzen stylea9721db0682f
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteGentzen-style sequent proofs are not formalized in Mathlib.
statusnot_formalized
modifiedNatural deduction3e9260334cd8
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteMathlib does not formalize natural deduction as an explicit proof system.
statusnot_formalized
modifiedSequent calculus line form87c7825df693
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteThe multi-conclusion sequent form is not defined in Mathlib.
statusnot_formalized
modifiedGentzen's Hauptsatz (cut-elimination)7f7385b069a8
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteCut-elimination / Hauptsatz is not in Mathlib (no hits for 'Hauptsatz' or 'cut elimination').
statusnot_formalized
modifiedConsistency of Peano arithmetic11c3bc6e5214
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteGentzen's transfinite consistency proof of PA is not formalized in Mathlib.
statusnot_formalized
modifiedHilbert-style judgment463d96cefb79
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteMathlib has no Hilbert-style judgment form.
statusnot_formalized
modifiedNatural deduction judgment043d7a433533
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteNatural-deduction judgments Γ ⊢ A are not formalized in Mathlib.
statusnot_formalized
modifiedSemantics of natural deduction judgmente422b9ae5fd2
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteNo formalized semantics of natural-deduction judgments in Mathlib.
statusnot_formalized
modifiedSequent880766f809f5
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteThere is no 'sequent' object defined in Mathlib (the 89 hits for 'sequent' are all 'sequence'/'sequential').
statusnot_formalized
modifiedAntecedent and succedentc46201d99a78
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteAntecedent/succedent terminology and the underlying sequent object are absent from Mathlib.
statusnot_formalized
modifiedSemantics of a sequentf326ad643b9d
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteSequent semantics ⋀Γ ⊨ ⋁Δ is not in Mathlib.
statusnot_formalized
modifiedEmpty sequent is false182ffe24f234
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteNo sequents are defined, so no statement about the empty sequent.
statusnot_formalized
modifiedClassical reformulations of sequent semantics958fcb3f047c
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteClassical equivalences of sequent semantics are not formalized in Mathlib.
statusnot_formalized
modifiedReduction tree example formulaebadc802a543
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteSpecific reduction-tree example is not in Mathlib.
statusnot_formalized
modifiedReduction treec15126b701ab
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteReduction trees for sequents are not defined in Mathlib.
statusnot_formalized
modifiedAxiom condition for atomic sequentsfb5dbb2a0ae1
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteNo formalization of the atomic-axiom criterion.
statusnot_formalized
modifiedSoundness and completeness of reduction-tree systemd394873b2142
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteSoundness/completeness of a reduction-tree calculus is not formalized in Mathlib.
statusnot_formalized
modifiedProvability via reduction trees69e84f8425ac
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteNo Mathlib statement linking Hilbert provability to reduction trees.
statusnot_formalized
modifiedFormal proof in LK619259b91d0e
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteLK proofs are not defined in Mathlib.
statusnot_formalized
modifiedFree variable occurrencea494e43e1370
FieldFrom #1558To #2185
mathlib.declFirstOrder.Language.BoundedFormula.freeVarFinset
mathlib.match_kindgeneralization
mathlib.moduleMathlib.ModelTheory.Syntax
noteMathlib's ModelTheory tracks free variables in first-order formulas (e.g. freeVarFinset), but not as part of a sequent-calculus inference system.
statuspartial
modifiedSubstitution notation27c55c818a61
FieldFrom #1558To #2185
mathlib.declFirstOrder.Language.BoundedFormula.subst
mathlib.match_kindgeneralization
mathlib.moduleMathlib.ModelTheory.Syntax
noteSubstitution of terms into first-order formulas exists in ModelTheory (e.g. BoundedFormula.subst), though not tied to LK notation.
statuspartial
modifiedStructural rule abbreviationsb056a39e4302
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteStructural inference rules (W/C/P) are not defined in Mathlib.
statusnot_formalized
modifiedCut-elimination theorem3364bc35f434
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteCut-elimination is not formalized in Mathlib.
statusnot_formalized
modifiedCompleteness of atomic initial sequents6527c3d1878a
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteNo formalization of restricting LK's initial rule to atomic formulas.
statusnot_formalized
modifiedLaw of excluded middle derivation3c7ef824fda4
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteThe LEM derivation in LK is not formalized; Mathlib has Classical.em as a logical axiom, not a sequent-calculus derivation.
statusnot_formalized
modifiedQuantifier fact derivationc1c55ef887c7
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteNo LK example derivations are formalized in Mathlib.
statusnot_formalized
modifiedLK derivation showing automated proving03d491c3e8ae
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteLK and automated derivation in LK are not formalized in Mathlib.
statusnot_formalized
modifiedSequent proof ↔ closed analytic tableau2631950d9ab8
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteMathlib has neither sequent proofs nor analytic tableaux to relate.
statusnot_formalized
modifiedWeakening rule95d791b659d1
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteNo Weakening inference rule is defined in Mathlib.
statusnot_formalized
modifiedContraction and Permutation7784176e4039
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteContraction and Permutation structural rules are not formalized in Mathlib.
statusnot_formalized
modifiedSubstructural logicsb1f46a3eb93b
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteSubstructural logics are not defined in Mathlib.
statusnot_formalized
modifiedSoundness and completeness of LK99e69bcc3ab2
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteLK soundness and completeness are not formalized in Mathlib (Mathlib has model-theoretic semantics but no LK proof system).
statusnot_formalized
modifiedAdmissibility of cut (Hauptsatz)ebe23e05c0f5
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteAdmissibility of cut in sequent calculus is not formalized in Mathlib.
statusnot_formalized
modifiedAdmissibility of weakening via modified axiom5cf79469df2a
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteVariants of LK's axiom rule and weakening admissibility are not in Mathlib.
statusnot_formalized
modifiedAbsurdity constant8e1c115e7564
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteNo object-level absurdity constant with a sequent-calculus axiom is defined in Mathlib (Lean's False is metalevel).
statusnot_formalized
modifiedNegation from implication3ac30411bf39
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteDefinition of ¬A := A → ⊥ inside a formal proof system is not given in Mathlib.
statusnot_formalized
modifiedSystem LJe04ee6ab443b
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteThe intuitionistic sequent calculus LJ is not defined in Mathlib.
statusnot_formalized
modifiedSoundness and completeness of LJadea44d23db0
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteLJ soundness/completeness and its cut-elimination are absent from Mathlib.
statusnot_formalized
modifiedDisjunction and existence properties9ad7e290763b
FieldFrom #1558To #2185
mathlib.decl
mathlib.match_kind
mathlib.module
noteIntuitionistic disjunction/existence properties for LJ are not formalized in Mathlib.
statusnot_formalized
addedSequent (Gentzen's terminology)65773e5bb160
addedCedents (sequent formulas)4aab0313c9dc
addedLeft–right symmetry from De Morgan duality1922335d590d
addedConjunction/disjunction reading of cedentsc3f434bd42a5
addedEigenvariable restriction on quantifier rulesdca83fdf242a
addedContexts (Γ, Δ)b24afc2e5c61
addedRestriction to single-formula succedents for LJeb24bc8ab1e8
addedModus ponens implemented by cuta28d91aa6cd6