Theory Transport_Compositions_Generic_Order_Base

✐‹creator "Kevin Kappelmann"›
subsection ‹Basic Order Properties›
theory Transport_Compositions_Generic_Order_Base
  imports
   Transport_Compositions_Generic_Base
begin

context transport_comp
begin

interpretation flip1 : galois R1 L1 r1 l1 .

subsubsection ‹Reflexivity›

lemma reflexive_on_in_dom_leftI:
  assumes galois_prop: "((≤L1)  (≤R1)) l1 r1"
  and in_dom_L1_le: "in_dom (≤L1)  in_codom (≤L1)"
  and refl_R1: "reflexive_on (in_dom (≤R1)) (≤R1)"
  and refl_L2: "reflexive_on (in_dom (≤L2)) (≤L2)"
  and mono_in_dom_l1: "(in_dom (≤L) m in_dom (≤L2)) l1"
  shows "reflexive_on (in_dom (≤L)) (≤L)"
proof (rule reflexive_onI)
  fix x assume "in_dom (≤L) x"
  then obtain x' where "xL x'" "in_dom (≤L1) x" by blast
  show "xL x"
  proof (rule left_relI)
    from refl_R1 have "l1 xR1 l1 x"
    proof (rule reflexive_onD)
      from xL x' galois_prop show "in_dom (≤R1) (l1 x)" by blast
    qed
    then show "x L1l1 x"
    proof (intro t1.left_GaloisI)
      from galois_prop in_dom (≤L1) x l1 xR1 l1 x show "xL1 r1 (l1 x)" by blast
    qed blast
    from refl_L2 show "l1 xL2 l1 x"
    proof (rule reflexive_onD)
      from mono_in_dom_l1 xL x' show "in_dom (≤L2) (l1 x)" by blast
    qed
    from l1 xR1 l1 x show "l1 x R1x"
    proof (intro flip1.left_GaloisI)
      from in_dom (≤L1) x in_dom_L1_le show "in_codom (≤L1) x" by blast
    qed
  qed
qed

lemma reflexive_on_in_codom_leftI:
  assumes L1_r1_l1I: "x. in_dom (≤L1) x  l1 xR1 l1 x  xL1 r1 (l1 x)"
  and in_codom_L1_le: "in_codom (≤L1)  in_dom (≤L1)"
  and refl_R1: "reflexive_on (in_codom (≤R1)) (≤R1)"
  and refl_L2: "reflexive_on (in_codom (≤L2)) (≤L2)"
  and mono_in_codom_l1: "(in_codom (≤L) m in_codom (≤L2)) l1"
  shows "reflexive_on (in_codom (≤L)) (≤L)"
proof (rule reflexive_onI)
  fix x assume "in_codom (≤L) x"
  then obtain x' where "x'L x" "in_codom (≤L1) x" "in_codom (≤R1) (l1 x)"
    by blast
  show "xL x"
  proof (rule left_relI)
    from refl_R1 in_codom (≤R1) (l1 x) have "l1 xR1 l1 x" by blast
    show "x L1l1 x"
    proof (rule t1.left_GaloisI)
      from in_codom_L1_le in_codom (≤L1) x have "in_dom (≤L1) x" by blast
      with l1 xR1 l1 x show "xL1 r1 (l1 x)" by (intro L1_r1_l1I)
    qed fact
    from refl_L2 show "l1 xL2 l1 x"
    proof (rule reflexive_onD)
      from mono_in_codom_l1 x'L x show "in_codom (≤L2) (l1 x)" by blast
    qed
    show "l1 x R1x" by (rule flip1.left_GaloisI) fact+
  qed
qed

corollary reflexive_on_in_field_leftI:
  assumes "((≤L1)  (≤R1)) l1 r1"
  and "in_codom (≤L1) = in_dom (≤L1)"
  and "reflexive_on (in_field (≤R1)) (≤R1)"
  and "reflexive_on (in_field (≤L2)) (≤L2)"
  and "(in_field (≤L) m in_field (≤L2)) l1"
  shows "reflexive_on (in_field (≤L)) (≤L)"
proof -
  from assms have "reflexive_on (in_dom (≤L)) (≤L)"
    by (intro reflexive_on_in_dom_leftI)
    (auto 0 5 intro: reflexive_on_if_le_pred_if_reflexive_on in_field_if_in_dom)
  moreover from assms have "reflexive_on (in_codom (≤L)) (≤L)"
    by (intro reflexive_on_in_codom_leftI)
    (auto 0 5 intro: reflexive_on_if_le_pred_if_reflexive_on in_field_if_in_codom)
  ultimately show ?thesis by (auto iff: in_field_iff_in_dom_or_in_codom)
qed


subsubsection ‹Transitivity›

text‹There are many similar proofs for transitivity. They slightly differ in
their assumptions, particularly which of @{term "(≤R1)"} and @{term "(≤L2)"} has
to be transitive and the order of commutativity for the relations.

In the following, we just give two of them that suffice for many purposes.›

lemma transitive_leftI:
  assumes "((≤L1) h (≤R1)) l1 r1"
  and trans_L2: "transitive (≤L2)"
  and R1_L2_R1_le: "((≤R1) ∘∘ (≤L2) ∘∘ (≤R1))  ((≤L2) ∘∘ (≤R1))"
  shows "transitive (≤L)"
proof (rule transitiveI)
  fix x1 x2 x3 assume "x1L x2" "x2L x3"
  from x1L x2 obtain y1 y2 where "x1 L1y1" "y1L2 y2" "y2R1 l1 x2"
    by blast
  from x2L x3 ((≤L1) h (≤R1)) l1 r1 obtain y3 y4 where
    "l1 x2R1 y3" "y3L2 y4" "y4R1 l1 x3" "in_codom (≤L1) x3" by blast
  with R1_L2_R1_le have "((≤L2) ∘∘ (≤R1)) (l1 x2) (l1 x3)" by blast
  then obtain y where "l1 x2L2 y" "yR1 l1 x3" by blast
  with y2R1 l1 x2 R1_L2_R1_le have "((≤L2) ∘∘ (≤R1)) y2 (l1 x3)" by blast
  then obtain y' where "y2L2 y'" "y'R1 l1 x3" by blast
  with y1L2 y2 have "y1L2 y'" using trans_L2 by blast
  show "x1L x3"
  proof (rule left_relI)
    show "x1 L1y1" "y1L2 y'" by fact+
    show "y' R1x3" by (rule flip1.left_GaloisI) fact+
  qed
qed

lemma transitive_leftI':
  assumes galois_prop: "((≤L1)  (≤R1)) l1 r1"
  and trans_L2: "transitive (≤L2)"
  and R1_L2_R1_le: "((≤R1) ∘∘ (≤L2) ∘∘ (≤R1))  ((≤R1) ∘∘ (≤L2))"
  shows "transitive (≤L)"
proof (rule transitiveI)
  fix x1 x2 x3 assume "x1L x2" "x2L x3"
  from x1L x2 galois_prop obtain y1 y2 where
    "in_dom (≤L1) x1" "l1 x1R1 y1" "y1L2 y2" "y2R1 l1 x2" by blast
  with R1_L2_R1_le have "((≤R1) ∘∘ (≤L2)) (l1 x1) (l1 x2)" by blast
  then obtain y where "l1 x1R1 y" "yL2 l1 x2" by blast
  moreover from x2L x3 galois_prop obtain y3 y4 where
    "l1 x2R1 y3" "y3L2 y4" "y4 R1x3" by blast
  moreover note R1_L2_R1_le
  ultimately have "((≤R1) ∘∘ (≤L2)) (l1 x1) y3" by blast
  then obtain y' where "l1 x1R1 y'" "y'L2 y3" by blast
  with y3L2 y4 have "y'L2 y4" using trans_L2 by blast
  show "x1L x3"
  proof (rule left_relI)
    from in_dom (≤L1) x1 l1 x1R1 y' galois_prop show "x1 L1y'"
      by (intro t1.left_Galois_if_Galois_right_if_half_galois_prop_right t1.left_GaloisI)
      auto
    show "y'L2 y4" by fact
    from y'L2 y4 y4 R1x3 show "y4 R1x3" by blast
  qed
qed


subsubsection ‹Preorders›

lemma preorder_on_in_field_leftI:
  assumes "((≤L1)  (≤R1)) l1 r1"
  and "in_codom (≤L1) = in_dom (≤L1)"
  and "reflexive_on (in_field (≤R1)) (≤R1)"
  and "preorder_on (in_field (≤L2)) (≤L2)"
  and mono_in_codom_l1: "(in_codom (≤L) m in_codom (≤L2)) l1"
  and R1_L2_R1_le: "((≤R1) ∘∘ (≤L2) ∘∘ (≤R1))  ((≤L2) ∘∘ (≤R1))"
  shows "preorder_on (in_field (≤L)) (≤L)"
proof -
  have "(in_field (≤L) m in_field (≤L2)) l1"
  proof -
    from ((≤L1)  (≤R1)) l1 r1 R1_L2_R1_le
      have "(in_dom (≤L) m in_dom (≤L2)) l1"
      by (intro mono_in_dom_left_rel_left1_if_in_dom_rel_comp_le
        in_dom_right1_left2_right1_le_if_right1_left2_right1_le)
      auto
    with mono_in_codom_l1 show ?thesis by (intro mono_wrt_predI) blast
  qed
  with assms show ?thesis by (intro preorder_onI)
    (auto intro: reflexive_on_in_field_leftI transitive_leftI)
qed

lemma preorder_on_in_field_leftI':
  assumes "((≤L1)  (≤R1)) l1 r1"
  and "in_codom (≤L1) = in_dom (≤L1)"
  and "reflexive_on (in_field (≤R1)) (≤R1)"
  and "preorder_on (in_field (≤L2)) (≤L2)"
  and mono_in_dom_l1: "(in_dom (≤L) m in_dom (≤L2)) l1"
  and R1_L2_R1_le: "((≤R1) ∘∘ (≤L2) ∘∘ (≤R1))  ((≤R1) ∘∘ (≤L2))"
  shows "preorder_on (in_field (≤L)) (≤L)"
proof -
  have "(in_field (≤L) m in_field (≤L2)) l1"
  proof -
    from ((≤L1)  (≤R1)) l1 r1 R1_L2_R1_le
      have "(in_codom (≤L) m in_codom (≤L2)) l1"
      by (intro mono_in_codom_left_rel_left1_if_in_codom_rel_comp_le
        in_codom_right1_left2_right1_le_if_right1_left2_right1_le)
      auto
    with mono_in_dom_l1 show ?thesis by (intro mono_wrt_predI) blast
  qed
  with assms show ?thesis by (intro preorder_onI)
    (auto intro: reflexive_on_in_field_leftI transitive_leftI')
qed


subsubsection ‹Symmetry›

lemma symmetric_leftI:
  assumes "((≤L1)  (≤R1)) l1 r1"
  and "in_codom (≤L1) = in_dom (≤L1)"
  and "symmetric (≤R1)"
  and "symmetric (≤L2)"
  shows "symmetric (≤L)"
proof -
  from assms have "(⪆R1) = (L1⪅)" by (intro
    t1.ge_Galois_right_eq_left_Galois_if_symmetric_if_in_codom_eq_in_dom_if_galois_prop)
  moreover then have "(R1⪅) = (⪆L1)"
    by (subst rel_inv_eq_iff_eq[symmetric]) simp
  ultimately show ?thesis using assms unfolding left_rel_eq_comp
    by (subst symmetric_iff_rel_inv_eq_self) (simp add: rel_comp_assoc)
qed

lemma partial_equivalence_rel_leftI:
  assumes "((≤L1)  (≤R1)) l1 r1"
  and "in_codom (≤L1) = in_dom (≤L1)"
  and "symmetric (≤R1)"
  and "partial_equivalence_rel (≤L2)"
  and "((≤R1) ∘∘ (≤L2) ∘∘ (≤R1))  ((≤L2) ∘∘ (≤R1))"
  shows "partial_equivalence_rel (≤L)"
  using assms by (intro partial_equivalence_relI transitive_leftI symmetric_leftI)
  auto

lemma partial_equivalence_rel_leftI':
  assumes "((≤L1)  (≤R1)) l1 r1"
  and "in_codom (≤L1) = in_dom (≤L1)"
  and "symmetric (≤R1)"
  and "partial_equivalence_rel (≤L2)"
  and "((≤R1) ∘∘ (≤L2) ∘∘ (≤R1))  ((≤R1) ∘∘ (≤L2))"
  shows "partial_equivalence_rel (≤L)"
  using assms by (intro partial_equivalence_relI transitive_leftI' symmetric_leftI)
  auto

end


end