From 298baf2b69620106e95b52206e02d58ad8cb9fc8 Mon Sep 17 00:00:00 2001
From: Jacques Comeaux <jacquesrcomeaux@protonmail.com>
Date: Mon, 3 Nov 2025 23:29:21 -0600
Subject: Use permutation for equivalence of hypergraphs

---
 Data/Hypergraph/Edge.agda | 368 ++++++++--------------------------------------
 1 file changed, 58 insertions(+), 310 deletions(-)

(limited to 'Data/Hypergraph/Edge.agda')

diff --git a/Data/Hypergraph/Edge.agda b/Data/Hypergraph/Edge.agda
index ee32393..1e24559 100644
--- a/Data/Hypergraph/Edge.agda
+++ b/Data/Hypergraph/Edge.agda
@@ -4,43 +4,32 @@ open import Data.Hypergraph.Label using (HypergraphLabel)
 
 module Data.Hypergraph.Edge (HL : HypergraphLabel) where
 
-import Data.List.Sort as ListSort
-import Data.Fin as Fin
-import Data.Fin.Properties as FinProp
 import Data.Vec as Vec
 import Data.Vec.Relation.Binary.Equality.Cast as VecCast
-import Data.Vec.Relation.Binary.Lex.Strict as Lex
 import Relation.Binary.PropositionalEquality as ≡
-import Relation.Binary.Properties.DecTotalOrder as DTOP
-import Relation.Binary.Properties.StrictTotalOrder as STOP
 
-open import Relation.Binary using (Rel; IsStrictTotalOrder; Tri; Trichotomous; _Respects_)
-open import Data.Castable using (IsCastable)
 open import Data.Fin using (Fin)
 open import Data.Fin.Show using () renaming (show to showFin)
-open import Data.Nat using (ℕ; _<_)
-open import Data.Nat.Properties using (<-irrefl; <-trans; <-resp₂-≡; <-cmp)
-open import Data.Product.Base using (_,_; proj₁; proj₂)
+open import Data.Nat using (ℕ)
 open import Data.String using (String; _<+>_)
-open import Data.Vec.Relation.Binary.Pointwise.Inductive using (≡⇒Pointwise-≡; Pointwise-≡⇒≡)
 open import Data.Vec.Show using () renaming (show to showVec)
 open import Level using (0ℓ)
-open import Relation.Binary using (Setoid; DecTotalOrder; StrictTotalOrder; IsEquivalence)
-open import Relation.Nullary using (¬_)
-
+open import Relation.Binary using (Setoid; IsEquivalence)
 
 module HL = HypergraphLabel HL
+
 open HL using (Label; cast; cast-is-id)
 open Vec using (Vec)
 
 record Edge (v : ℕ) : Set where
+  constructor mkEdge
   field
     {arity} : ℕ
     label : Label arity
     ports : Vec (Fin v) arity
 
 map : {n m : ℕ} → (Fin n → Fin m) → Edge n → Edge m
-map {n} {m} f edge = record
+map f edge = record
     { label = label
     ; ports = Vec.map f ports
     }
@@ -50,299 +39,58 @@ map {n} {m} f edge = record
 open ≡ using (_≡_)
 open VecCast using (_≈[_]_)
 
-record ≈-Edge {n : ℕ} (E E′ : Edge n) : Set where
-  module E = Edge E
-  module E′ = Edge E′
-  field
-    ≡arity : E.arity ≡ E′.arity
-    ≡label : cast ≡arity E.label ≡ E′.label
-    ≡ports : E.ports ≈[ ≡arity ] E′.ports
-
-≈-Edge-refl : {v : ℕ} {x : Edge v} → ≈-Edge x x
-≈-Edge-refl {_} {x} = record
-    { ≡arity = ≡.refl
-    ; ≡label = HL.≈-reflexive ≡.refl
-    ; ≡ports = VecCast.≈-reflexive ≡.refl
-    }
-  where
-    open Edge x using (arity; label)
-    open DecTotalOrder (HL.decTotalOrder arity) using (module Eq)
-
-≈-Edge-sym : {v : ℕ} {x y : Edge v} → ≈-Edge x y → ≈-Edge y x
-≈-Edge-sym {_} {x} {y} x≈y = record
-    { ≡arity = ≡.sym ≡arity
-    ; ≡label = HL.≈-sym ≡label
-    ; ≡ports = VecCast.≈-sym ≡ports
-    }
-  where
-    open ≈-Edge x≈y
-    open DecTotalOrder (HL.decTotalOrder E.arity) using (module Eq)
-
-≈-Edge-trans : {v : ℕ} {i j k : Edge v} → ≈-Edge i j → ≈-Edge j k → ≈-Edge i k
-≈-Edge-trans {_} {i} {j} {k} i≈j j≈k = record
-    { ≡arity = ≡.trans i≈j.≡arity j≈k.≡arity
-    ; ≡label = HL.≈-trans i≈j.≡label j≈k.≡label
-    ; ≡ports = VecCast.≈-trans i≈j.≡ports j≈k.≡ports
-    }
-  where
-    module i≈j = ≈-Edge i≈j
-    module j≈k = ≈-Edge j≈k
-
-≈-Edge-IsEquivalence : {v : ℕ} → IsEquivalence (≈-Edge {v})
-≈-Edge-IsEquivalence = record
-    { refl = ≈-Edge-refl
-    ; sym = ≈-Edge-sym
-    ; trans = ≈-Edge-trans
-    }
-
-open HL using (_[_<_])
-_<<_ : {v a : ℕ} → Rel (Vec (Fin v) a) 0ℓ
-_<<_ {v} = Lex.Lex-< _≡_ (Fin._<_ {v})
-data <-Edge {v : ℕ} : Edge v → Edge v → Set where
-  <-arity
-      : {x y : Edge v}
-      → Edge.arity x < Edge.arity y
-      → <-Edge x y
-  <-label
-      : {x y : Edge v}
-        (≡a : Edge.arity x ≡ Edge.arity y)
-      → Edge.arity y [ cast ≡a (Edge.label x) < Edge.label y ]
-      → <-Edge x y
-  <-ports
-      : {x y : Edge v}
-        (≡a : Edge.arity x ≡ Edge.arity y)
-        (≡l : Edge.label x HL.≈[ ≡a ] Edge.label y)
-      → Vec.cast ≡a (Edge.ports x) << Edge.ports y
-      → <-Edge x y
-
-<-Edge-irrefl : {v : ℕ} {x y : Edge v} → ≈-Edge x y → ¬ <-Edge x y
-<-Edge-irrefl record { ≡arity = ≡a } (<-arity n<m) = <-irrefl ≡a n<m
-<-Edge-irrefl record { ≡label = ≡l } (<-label _ (_ , x≉y)) = x≉y ≡l
-<-Edge-irrefl record { ≡ports = ≡p } (<-ports ≡.refl ≡l x<y)
-    = Lex.<-irrefl FinProp.<-irrefl (≡⇒Pointwise-≡ ≡p) x<y
-
-<-Edge-trans : {v : ℕ} {i j k : Edge v} → <-Edge i j → <-Edge j k → <-Edge i k
-<-Edge-trans (<-arity i<j) (<-arity j<k) = <-arity (<-trans i<j j<k)
-<-Edge-trans (<-arity i<j) (<-label ≡.refl j<k) = <-arity i<j
-<-Edge-trans (<-arity i<j) (<-ports ≡.refl _ j<k) = <-arity i<j
-<-Edge-trans (<-label ≡.refl i<j) (<-arity j<k) = <-arity j<k
-<-Edge-trans {_} {i} (<-label ≡.refl i<j) (<-label ≡.refl j<k)
-    = <-label ≡.refl (<-label-trans i<j (<-respˡ-≈ (HL.≈-reflexive ≡.refl) j<k))
-  where
-    open DTOP (HL.decTotalOrder (Edge.arity i)) using (<-respˡ-≈) renaming (<-trans to <-label-trans)
-<-Edge-trans {k = k} (<-label ≡.refl i<j) (<-ports ≡.refl ≡.refl _)
-    = <-label ≡.refl (<-respʳ-≈ (≡.sym (HL.≈-reflexive ≡.refl)) i<j)
-  where
-    open DTOP (HL.decTotalOrder (Edge.arity k)) using (<-respʳ-≈)
-<-Edge-trans (<-ports ≡.refl _ _) (<-arity j<k) = <-arity j<k
-<-Edge-trans {k = k} (<-ports ≡.refl ≡.refl _) (<-label ≡.refl j<k)
-    = <-label ≡.refl (<-respˡ-≈ (≡.cong (cast _) (HL.≈-reflexive ≡.refl)) j<k)
-  where
-    open DTOP (HL.decTotalOrder (Edge.arity k)) using (<-respˡ-≈)
-<-Edge-trans {j = j} (<-ports ≡.refl ≡l₁ i<j) (<-ports ≡.refl ≡l₂ j<k)
-  rewrite (VecCast.cast-is-id ≡.refl (Edge.ports j))
-    = <-ports ≡.refl
-        (HL.≈-trans ≡l₁ ≡l₂)
-        (Lex.<-trans ≡-isPartialEquivalence FinProp.<-resp₂-≡ FinProp.<-trans i<j j<k)
-  where
-    open IsEquivalence ≡.isEquivalence using () renaming (isPartialEquivalence to ≡-isPartialEquivalence)
-
-<-Edge-respˡ-≈ : {v : ℕ} {y : Edge v} → (λ x → <-Edge x y) Respects ≈-Edge
-<-Edge-respˡ-≈ ≈x (<-arity x₁<y) = <-arity (proj₂ <-resp₂-≡ ≡arity x₁<y)
-  where
-    open ≈-Edge ≈x using (≡arity)
-<-Edge-respˡ-≈ {_} {y} record { ≡arity = ≡.refl ; ≡label = ≡.refl } (<-label ≡.refl x₁<y)
-    = <-label ≡.refl (<-respˡ-≈ (≡.sym (HL.≈-reflexive ≡.refl)) x₁<y)
-  where
-    module y = Edge y
-    open DTOP (HL.decTotalOrder y.arity) using (<-respˡ-≈)
-<-Edge-respˡ-≈ record { ≡arity = ≡.refl ; ≡label = ≡.refl; ≡ports = ≡.refl} (<-ports ≡.refl ≡.refl x₁<y)
-    = <-ports
-        ≡.refl
-        (≡.cong (cast _) (HL.≈-reflexive ≡.refl))
-        (Lex.<-respectsˡ
-            ≡-isPartialEquivalence
-            FinProp.<-respˡ-≡
-            (≡⇒Pointwise-≡ (≡.sym (VecCast.≈-reflexive ≡.refl)))
-            x₁<y)
-  where
-    open IsEquivalence ≡.isEquivalence using () renaming (isPartialEquivalence to ≡-isPartialEquivalence)
-
-<-Edge-respʳ-≈ : {v : ℕ} {x : Edge v} → <-Edge x Respects ≈-Edge
-<-Edge-respʳ-≈ record { ≡arity = ≡a } (<-arity x<y₁) = <-arity (proj₁ <-resp₂-≡ ≡a x<y₁)
-<-Edge-respʳ-≈ {_} {x} record { ≡arity = ≡.refl ; ≡label = ≡.refl } (<-label ≡.refl x<y₁)
-    = <-label ≡.refl (<-respʳ-≈ (≡.sym (HL.≈-reflexive ≡.refl)) x<y₁)
-  where
-    module x = Edge x
-    open DTOP (HL.decTotalOrder x.arity) using (<-respʳ-≈)
-<-Edge-respʳ-≈ record { ≡arity = ≡.refl ; ≡label = ≡.refl; ≡ports = ≡.refl} (<-ports ≡.refl ≡.refl x<y₁)
-    = <-ports
-        ≡.refl
-        (≡.cong (cast _) (≡.sym (HL.≈-reflexive ≡.refl)))
-        (Lex.<-respectsʳ
-            ≡-isPartialEquivalence
-            FinProp.<-respʳ-≡
-            (≡⇒Pointwise-≡ (≡.sym (VecCast.≈-reflexive ≡.refl)))
-            x<y₁)
-  where
-    open IsEquivalence ≡.isEquivalence using () renaming (isPartialEquivalence to ≡-isPartialEquivalence)
-
-open Tri
-open ≈-Edge
-tri : {v : ℕ} → Trichotomous (≈-Edge {v}) (<-Edge {v})
-tri x y with <-cmp x.arity y.arity
-  where
-    module x = Edge x
-    module y = Edge y
-tri x y | tri< x<y x≢y y≮x = tri< (<-arity x<y) (λ x≡y → x≢y (≡arity x≡y)) ¬y<x
-  where
-    ¬y<x :  ¬ <-Edge y x
-    ¬y<x (<-arity y<x) = y≮x y<x
-    ¬y<x (<-label ≡a _) = x≢y (≡.sym ≡a)
-    ¬y<x (<-ports ≡a _ _) = x≢y (≡.sym ≡a)
-tri x y | tri≈ x≮y ≡.refl y≮x = compare-label
-  where
-    module x = Edge x
-    module y = Edge y
-    open StrictTotalOrder (HL.strictTotalOrder x.arity) using (compare)
-    import Relation.Binary.Properties.DecTotalOrder
-    open DTOP (HL.decTotalOrder x.arity) using (<-respˡ-≈)
-    compare-label : Tri (<-Edge x y) (≈-Edge x y) (<-Edge y x)
-    compare-label with compare x.label y.label
-    ... | tri< x<y x≢y y≮x′ = tri<
-            (<-label ≡.refl (<-respˡ-≈ (≡.sym (HL.≈-reflexive ≡.refl)) x<y))
-            (λ x≡y → x≢y (≡.trans (≡.sym (HL.≈-reflexive ≡.refl)) (≡label x≡y)))
-            ¬y<x
-      where
-        ¬y<x :  ¬ <-Edge y x
-        ¬y<x (<-arity y<x) = y≮x y<x
-        ¬y<x (<-label _ y<x) = y≮x′ (<-respˡ-≈ (HL.≈-reflexive ≡.refl) y<x)
-        ¬y<x (<-ports _ ≡l _) = x≢y (≡.trans (≡.sym ≡l) (cast-is-id ≡.refl y.label))
-    ... | tri≈ x≮y′ x≡y′ y≮x′ = compare-ports
-      where
-        compare-ports : Tri (<-Edge x y) (≈-Edge x y) (<-Edge y x)
-        compare-ports with Lex.<-cmp ≡.sym FinProp.<-cmp x.ports y.ports
-        ... | tri< x<y x≢y y≮x″ =
-                tri<
-                  (<-ports ≡.refl
-                    (HL.≈-reflexive x≡y′)
-                    (Lex.<-respectsˡ
-                      ≡-isPartialEquivalence
-                      FinProp.<-respˡ-≡
-                      (≡⇒Pointwise-≡ (≡.sym (VecCast.≈-reflexive ≡.refl)))
-                      x<y))
-                  (λ x≡y → x≢y (≡⇒Pointwise-≡ (≡.trans (≡.sym (VecCast.≈-reflexive ≡.refl)) (≡ports x≡y))))
-                  ¬y<x
-          where
-            open IsEquivalence ≡.isEquivalence using () renaming (isPartialEquivalence to ≡-isPartialEquivalence)
-            ¬y<x :  ¬ <-Edge y x
-            ¬y<x (<-arity y<x) = y≮x y<x
-            ¬y<x (<-label _ y<x) = y≮x′ (<-respˡ-≈ (HL.≈-reflexive ≡.refl) y<x)
-            ¬y<x (<-ports _ _ y<x) =
-                y≮x″
-                  (Lex.<-respectsˡ
-                    ≡-isPartialEquivalence
-                    FinProp.<-respˡ-≡
-                    (≡⇒Pointwise-≡ (VecCast.≈-reflexive ≡.refl))
-                    y<x)
-        ... | tri≈ x≮y″ x≡y″ y≮x″ = tri≈
-                ¬x<y
-                (record { ≡arity = ≡.refl ; ≡label = HL.≈-reflexive x≡y′ ; ≡ports = VecCast.≈-reflexive (Pointwise-≡⇒≡ x≡y″) })
-                ¬y<x
-          where
-            open IsEquivalence ≡.isEquivalence using () renaming (isPartialEquivalence to ≡-isPartialEquivalence)
-            ¬x<y : ¬ <-Edge x y
-            ¬x<y (<-arity x<y) = x≮y x<y
-            ¬x<y (<-label _ x<y) = x≮y′ (<-respˡ-≈ (HL.≈-reflexive ≡.refl) x<y)
-            ¬x<y (<-ports _ _ x<y) =
-                x≮y″
-                  (Lex.<-respectsˡ
-                    ≡-isPartialEquivalence
-                    FinProp.<-respˡ-≡
-                    (≡⇒Pointwise-≡ (VecCast.≈-reflexive ≡.refl))
-                    x<y)
-            ¬y<x : ¬ <-Edge y x
-            ¬y<x (<-arity y<x) = y≮x y<x
-            ¬y<x (<-label _ y<x) = y≮x′ (<-respˡ-≈ (HL.≈-reflexive ≡.refl) y<x)
-            ¬y<x (<-ports _ _ y<x) =
-                y≮x″
-                  (Lex.<-respectsˡ
-                    ≡-isPartialEquivalence
-                    FinProp.<-respˡ-≡
-                    (≡⇒Pointwise-≡ (VecCast.≈-reflexive ≡.refl))
-                    y<x)
-
-        ... | tri> x≮y″ x≢y y<x =
-                tri>
-                  ¬x<y
-                  (λ x≡y → x≢y (≡⇒Pointwise-≡ (≡.trans (≡.sym (VecCast.≈-reflexive ≡.refl)) (≡ports x≡y))))
-                  (<-ports
-                    ≡.refl
-                    (HL.≈-sym (HL.≈-reflexive x≡y′))
-                    (Lex.<-respectsˡ
-                      ≡-isPartialEquivalence
-                      FinProp.<-respˡ-≡
-                      (≡⇒Pointwise-≡ (≡.sym (VecCast.≈-reflexive ≡.refl)))
-                      y<x))
-          where
-            open IsEquivalence ≡.isEquivalence using () renaming (isPartialEquivalence to ≡-isPartialEquivalence)
-            ¬x<y : ¬ <-Edge x y
-            ¬x<y (<-arity x<y) = x≮y x<y
-            ¬x<y (<-label _ x<y) = x≮y′ (<-respˡ-≈ (HL.≈-reflexive ≡.refl) x<y)
-            ¬x<y (<-ports _ _ x<y) =
-                x≮y″
-                  (Lex.<-respectsˡ
-                    ≡-isPartialEquivalence
-                    FinProp.<-respˡ-≡
-                    (≡⇒Pointwise-≡ (VecCast.≈-reflexive ≡.refl))
-                    x<y)
-    ... | tri> x≮y′ x≢y y<x = tri>
-            ¬x<y
-            (λ x≡y → x≢y (≡.trans (≡.sym (HL.≈-reflexive ≡.refl)) (≡label x≡y)))
-            (<-label ≡.refl (<-respˡ-≈ (≡.sym (HL.≈-reflexive ≡.refl)) y<x))
-      where
-        ¬x<y : ¬ <-Edge x y
-        ¬x<y (<-arity x<y) = x≮y x<y
-        ¬x<y (<-label ≡a x<y) = x≮y′ (<-respˡ-≈ (HL.≈-reflexive ≡.refl) x<y)
-        ¬x<y (<-ports _ ≡l _) = x≢y (≡.trans (≡.sym (HL.≈-reflexive ≡.refl)) ≡l)
-tri x y | tri> x≮y x≢y y<x = tri> ¬x<y (λ x≡y → x≢y (≡arity x≡y)) (<-arity y<x)
-  where
-    ¬x<y :  ¬ <-Edge x y
-    ¬x<y (<-arity x<y) = x≮y x<y
-    ¬x<y (<-label ≡a x<y) = x≢y ≡a
-    ¬x<y (<-ports ≡a _ _) = x≢y ≡a
-
-isStrictTotalOrder : {v : ℕ} → IsStrictTotalOrder (≈-Edge {v}) (<-Edge {v})
-isStrictTotalOrder = record
-    { isStrictPartialOrder = record
-        { isEquivalence = ≈-Edge-IsEquivalence
-        ; irrefl = <-Edge-irrefl
-        ; trans = <-Edge-trans
-        ; <-resp-≈ = <-Edge-respʳ-≈ , <-Edge-respˡ-≈
-        }
-    ; compare = tri
-    }
-
-strictTotalOrder : {v : ℕ} → StrictTotalOrder 0ℓ 0ℓ 0ℓ
-strictTotalOrder {v} = record
-    { Carrier = Edge v
-    ; _≈_ = ≈-Edge {v}
-    ; _<_ = <-Edge {v}
-    ; isStrictTotalOrder = isStrictTotalOrder {v}
-    }
-
-show : {v : ℕ} → Edge v → String
-show record { arity = a ; label = l ; ports = p} = HL.showLabel a l <+> showVec showFin p
-
-open module STOP′ {v} = STOP (strictTotalOrder {v}) using (decTotalOrder) public
-
-≈-Edge⇒≡ : {v : ℕ} {x y : Edge v} → ≈-Edge x y → x ≡ y
-≈-Edge⇒≡ {v} {record { label = l ; ports = p }} record { ≡arity = ≡.refl ; ≡label = ≡.refl ; ≡ports = ≡.refl }
-  rewrite cast-is-id ≡.refl l
-  rewrite VecCast.cast-is-id ≡.refl p = ≡.refl
-
-module Sort {v} = ListSort (decTotalOrder {v})
-open Sort using (sort) public
+module _ {v : ℕ} where
+
+  -- an equivalence relation on edges with v nodes
+  record _≈_ (E E′ : Edge v) : Set where
+    constructor mk≈
+    module E = Edge E
+    module E′ = Edge E′
+    field
+      ≡arity : E.arity ≡ E′.arity
+      ≡label : cast ≡arity E.label ≡ E′.label
+      ≡ports : E.ports ≈[ ≡arity ] E′.ports
+
+  ≈-refl : {x : Edge v} → x ≈ x
+  ≈-refl = record
+      { ≡arity = ≡.refl
+      ; ≡label = HL.≈-reflexive ≡.refl
+      ; ≡ports = VecCast.≈-reflexive ≡.refl
+      }
+
+  ≈-sym : {x y : Edge v} → x ≈ y → y ≈ x
+  ≈-sym x≈y = record
+      { ≡arity = ≡.sym ≡arity
+      ; ≡label = HL.≈-sym ≡label
+      ; ≡ports = VecCast.≈-sym ≡ports
+      }
+    where
+      open _≈_ x≈y
+
+  ≈-trans : {i j k : Edge v} → i ≈ j → j ≈ k → i ≈ k
+  ≈-trans {i} {j} {k} i≈j j≈k = record
+      { ≡arity = ≡.trans i≈j.≡arity j≈k.≡arity
+      ; ≡label = HL.≈-trans i≈j.≡label j≈k.≡label
+      ; ≡ports = VecCast.≈-trans i≈j.≡ports j≈k.≡ports
+      }
+    where
+      module i≈j = _≈_ i≈j
+      module j≈k = _≈_ j≈k
+
+  ≈-IsEquivalence : IsEquivalence _≈_
+  ≈-IsEquivalence = record
+      { refl = ≈-refl
+      ; sym = ≈-sym
+      ; trans = ≈-trans
+      }
+
+  show : Edge v → String
+  show (mkEdge {a} l p) = HL.showLabel a l <+> showVec showFin p
+
+  ≈⇒≡ : {x y : Edge v} → x ≈ y → x ≡ y
+  ≈⇒≡ {mkEdge l p} (mk≈ ≡.refl ≡.refl ≡.refl)
+    rewrite cast-is-id ≡.refl l
+    rewrite VecCast.cast-is-id ≡.refl p = ≡.refl
 
 Edgeₛ : (v : ℕ) → Setoid 0ℓ 0ℓ
-Edgeₛ v = record { isEquivalence = ≈-Edge-IsEquivalence {v} }
+Edgeₛ v = record { isEquivalence = ≈-IsEquivalence {v} }
-- 
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