(* PROPERTIES OF RELATIONS **************************************************)
+definition relation5 : Type[0] → Type[0] → Type[0] → Type[0] → Type[0] → Type[0]
+≝ λA,B,C,D,E.A→B→C→D→E→Prop.
+
+definition relation6 : Type[0] → Type[0] → Type[0] → Type[0] → Type[0] → Type[0] → Type[0]
+≝ λA,B,C,D,E,F.A→B→C→D→E→F→Prop.
+
definition Decidable: Prop → Prop ≝ λR. R ∨ (R → ⊥).
definition Transitive: ∀A. ∀R: relation A. Prop ≝ λA,R.
definition right_cancellable: ∀A. ∀R: relation A. Prop ≝ λA,R.
∀a1,a0. R a1 a0 → ∀a2. R a2 a0 → R a1 a2.
-definition confluent2: ∀A. ∀R1,R2: relation A. Prop ≝ λA,R1,R2.
- ∀a0,a1. R1 a0 a1 → ∀a2. R2 a0 a2 →
- ∃∃a. R2 a1 a & R1 a2 a.
+definition pw_confluent2: ∀A. relation A → relation A → predicate A ≝ λA,R1,R2,a0.
+ ∀a1. R1 a0 a1 → ∀a2. R2 a0 a2 →
+ ∃∃a. R2 a1 a & R1 a2 a.
+
+definition confluent2: ∀A. relation (relation A) ≝ λA,R1,R2.
+ ∀a0. pw_confluent2 A R1 R2 a0.
definition transitive2: ∀A. ∀R1,R2: relation A. Prop ≝ λA,R1,R2.
∀a1,a0. R1 a1 a0 → ∀a2. R2 a0 a2 →
qed.
definition NF: ∀A. relation A → relation A → predicate A ≝
- λA,R,S,a1. ∀a2. R a1 a2 → S a2 a1.
+ λA,R,S,a1. ∀a2. R a1 a2 → S a1 a2.
definition NF_dec: ∀A. relation A → relation A → Prop ≝
λA,R,S. ∀a1. NF A R S a1 ∨
- ∃∃a2. R … a1 a2 & (S a2 a1 → ⊥).
+ ∃∃a2. R … a1 a2 & (S a1 a2 → ⊥).
inductive SN (A) (R,S:relation A): predicate A ≝
-| SN_intro: ∀a1. (∀a2. R a1 a2 → (S a2 a1 → ⊥) → SN A R S a2) → SN A R S a1
+| SN_intro: ∀a1. (∀a2. R a1 a2 → (S a1 a2 → ⊥) → SN A R S a2) → SN A R S a1
.
lemma NF_to_SN: ∀A,R,S,a. NF A R S a → SN A R S a.
qed-.
definition NF_sn: ∀A. relation A → relation A → predicate A ≝
- λA,R,S,a2. ∀a1. R a1 a2 → S a2 a1.
+ λA,R,S,a2. ∀a1. R a1 a2 → S a1 a2.
inductive SN_sn (A) (R,S:relation A): predicate A ≝
-| SN_sn_intro: ∀a2. (∀a1. R a1 a2 → (S a2 a1 → ⊥) → SN_sn A R S a1) → SN_sn A R S a2
+| SN_sn_intro: ∀a2. (∀a1. R a1 a2 → (S a1 a2 → ⊥) → SN_sn A R S a1) → SN_sn A R S a2
.
lemma NF_to_SN_sn: ∀A,R,S,a. NF_sn A R S a → SN_sn A R S a.