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make goedel1 statement a little more abstract
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Casteran committed Aug 27, 2023
1 parent 0d5ba08 commit a9a5713
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29 changes: 17 additions & 12 deletions theories/goedel/goedel1.v
Original file line number Diff line number Diff line change
Expand Up @@ -17,14 +17,23 @@ From LibHyps Require Export LibHyps.
From hydras Require Export MoreLibHyps NewNotations.
Import NNnotations.

Section Goedel's_1st_Incompleteness.
Definition codeFormula :=
codeFormula LNN codeLNTFunction codeLNNRelation.

Definition codeFormula := codeFormula LNN codeLNTFunction codeLNNRelation.
(* cf Gilles' paper ? *)
Notation reflection f := (natToTerm (codeFormula f)).

Section Goedel's_1st_Incompleteness.

Variable T : System.

Hypothesis extendsNN : Included _ NN T.

(*
There exists a formula repT
- with only a free variable v0
- which means "v0 is a term which reflects some axiom of T"
*)
Variable repT : Formula.
Variable v0 : nat.
Hypothesis
Expand All @@ -33,13 +42,13 @@ Hypothesis
expressT1 :
forall f : Formula,
mem _ T f ->
SysPrf T (substF LNN repT v0 (natToTerm (codeFormula f))).
SysPrf T (substF LNN repT v0 (reflection f)).
Hypothesis
expressT2 :
forall f : Formula,
~ mem _ T f ->
SysPrf T
(notH (substF LNN repT v0 (natToTerm (codeFormula f)))).
(notH (substF LNN repT v0 (reflection f))).

Definition codeSysPrf :=
codeSysPrf LNN codeLNTFunction codeLNNRelation codeArityLNTF codeArityLNNR
Expand Down Expand Up @@ -101,13 +110,9 @@ Proof.
(substF LNN (notH codeSysPf) 0
(codeNatToTerm.natToTermLNN
(code.codeFormula LNN codeLNTFunction codeLNNRelation x)))).
+ apply cp2.
apply iffE1.
apply sysExtend with NN.
* assumption.
* apply H1.
+ rewrite (subFormulaNot LNN); apply nnI.
apply codeSysPfCorrect; assumption.
+ apply cp2, iffE1; apply sysExtend with NN; auto.
+ rewrite (subFormulaNot LNN); apply nnI;
now apply codeSysPfCorrect.
Qed.

(*I don't believe I can prove
Expand Down Expand Up @@ -291,5 +296,5 @@ Qed.

End Goedel's_1st_Incompleteness.


About Goedel'sIncompleteness1st.

1 change: 1 addition & 0 deletions theories/ordinals/Ackermann/LNN.v
Original file line number Diff line number Diff line change
Expand Up @@ -411,3 +411,4 @@ intros a v; induction a as [| a Hreca].
Qed.



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