@@ -156,7 +156,7 @@ Like `A1`, this cannot be derived from primitive operators.
156156Vromen proves it as a theorem from the compositional structure of reason terms.
157157-/
158158
159- variable (A6 : ∀ {i j : indiv} {u : Prop }, Ind A i (R j A) ∧ R i (Ind A j u ) → Ind A i (R j u ))
159+ variable (A6 : ∀ {i j : indiv} {p : Prop }, Ind A i (R j A) ∧ R i (Ind A j p ) → Ind A i (R j p ))
160160
161161/-!
162162---
@@ -199,9 +199,9 @@ variable (C3 : ∀ i : indiv, Ind A i φ)
199199/-!
200200### Condition `C4`: Shared Inductive Standards
201201
202- If `A` indicates `u ` to `i`, then `i` has reason to believe that `A` indicates `u ` to `j`.
202+ If `A` indicates `p ` to `i`, then `i` has reason to believe that `A` indicates `p ` to `j`.
203203
204- > **Formula:** `Ind A i u → R i (Ind A j u )`
204+ > **Formula:** `Ind A i p → R i (Ind A j p )`
205205
206206This formalizes shared reasoning standards—agents know they reason alike.
207207This formalizes Lewis' assumption about "common inductive standards and background information".
@@ -212,7 +212,7 @@ necessary - we only need it for certain types of propositions. But it
212212simplifies the formalization.
213213-/
214214
215- variable (C4 : ∀ {i j : indiv} {u : Prop }, Ind A i u → R i (Ind A j u ))
215+ variable (C4 : ∀ {i j : indiv} {p : Prop }, Ind A i p → R i (Ind A j p ))
216216
217217include A1 A6 C1 C2 C3 C4
218218
@@ -349,7 +349,7 @@ The R-closure of `φ` is the smallest set of propositions that:
349349
350350inductive RC (φ : Prop ) : Prop → Prop where
351351 | base : RC φ φ
352- | step {u : Prop } (j : indiv) (hu : RC φ u ) : RC φ (R j u )
352+ | step {p : Prop } (j : indiv) (hu : RC φ p ) : RC φ (R j p )
353353
354354/-!
355355### Key Lemma: Indication Propagates Through R-Closure
@@ -366,7 +366,7 @@ indicate not just `φ`, but all its higher-order iterations.
366366 -/
367367
368368omit A1 C1 in
369- lemma rc_implies_indication {i : indiv} {q : Prop } (h : @RC indiv R φ q) : Ind A i q := by
369+ lemma indication_closure {i : indiv} {q : Prop } (h : @RC indiv R φ q) : Ind A i q := by
370370 induction h with
371371 | base => exact C3 i
372372 | @step v j _ ih =>
@@ -388,11 +388,12 @@ in `P` that `x`, then `r^P(x)` is true."
388388**Significance:** Common knowledge is not an infinite regress (circular) but an infinite *consequence* of finite, non-circular conditions.
389389-/
390390
391- lemma everyone_reason_of_rc (hp : @RC indiv R φ p) : ∀ i : indiv, R i p := by
391+ lemma lewis_theorem (hp : @RC indiv R φ p) : ∀ i : indiv, R i p := by
392392 intro i
393- have hInd : Ind A i p := rc_implies_indication A φ A6 C2 C3 C4 hp
393+ have hInd : Ind A i p := indication_closure A φ A6 C2 C3 C4 hp
394394 exact A1 hInd (C1 i)
395395
396+
396397end Lewis
397398
398399/-!
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