src/HOL/Library/Quotient_Option.thy
changeset 55466 786edc984c98
parent 53026 e1a548c11845
child 55525 70b7e91fa1f9
equal deleted inserted replaced
55465:0d31c0546286 55466:786edc984c98
     9 begin
     9 begin
    10 
    10 
    11 subsection {* Rules for the Quotient package *}
    11 subsection {* Rules for the Quotient package *}
    12 
    12 
    13 lemma option_rel_map1:
    13 lemma option_rel_map1:
    14   "option_rel R (Option.map f x) y \<longleftrightarrow> option_rel (\<lambda>x. R (f x)) x y"
    14   "option_rel R (map_option f x) y \<longleftrightarrow> option_rel (\<lambda>x. R (f x)) x y"
    15   by (simp add: option_rel_def split: option.split)
    15   by (simp add: option_rel_def split: option.split)
    16 
    16 
    17 lemma option_rel_map2:
    17 lemma option_rel_map2:
    18   "option_rel R x (Option.map f y) \<longleftrightarrow> option_rel (\<lambda>x y. R x (f y)) x y"
    18   "option_rel R x (map_option f y) \<longleftrightarrow> option_rel (\<lambda>x y. R x (f y)) x y"
    19   by (simp add: option_rel_def split: option.split)
    19   by (simp add: option_rel_def split: option.split)
    20 
    20 
    21 lemma option_map_id [id_simps]:
    21 declare
    22   "Option.map id = id"
    22   map_option.id [id_simps]
    23   by (simp add: id_def Option.map.identity fun_eq_iff)
    23   option_rel_eq [id_simps]
    24 
       
    25 lemma option_rel_eq [id_simps]:
       
    26   "option_rel (op =) = (op =)"
       
    27   by (simp add: option_rel_def fun_eq_iff split: option.split)
       
    28 
    24 
    29 lemma option_symp:
    25 lemma option_symp:
    30   "symp R \<Longrightarrow> symp (option_rel R)"
    26   "symp R \<Longrightarrow> symp (option_rel R)"
    31   unfolding symp_def split_option_all option_rel_simps by fast
    27   unfolding symp_def split_option_all option_rel_simps by fast
    32 
    28 
    38   "equivp R \<Longrightarrow> equivp (option_rel R)"
    34   "equivp R \<Longrightarrow> equivp (option_rel R)"
    39   by (blast intro: equivpI reflp_option_rel option_symp option_transp elim: equivpE)
    35   by (blast intro: equivpI reflp_option_rel option_symp option_transp elim: equivpE)
    40 
    36 
    41 lemma option_quotient [quot_thm]:
    37 lemma option_quotient [quot_thm]:
    42   assumes "Quotient3 R Abs Rep"
    38   assumes "Quotient3 R Abs Rep"
    43   shows "Quotient3 (option_rel R) (Option.map Abs) (Option.map Rep)"
    39   shows "Quotient3 (option_rel R) (map_option Abs) (map_option Rep)"
    44   apply (rule Quotient3I)
    40   apply (rule Quotient3I)
    45   apply (simp_all add: Option.map.compositionality comp_def Option.map.identity option_rel_eq option_rel_map1 option_rel_map2 Quotient3_abs_rep [OF assms] Quotient3_rel_rep [OF assms])
    41   apply (simp_all add: option.map_comp comp_def option.map_id[unfolded id_def] option_rel_eq option_rel_map1 option_rel_map2 Quotient3_abs_rep [OF assms] Quotient3_rel_rep [OF assms])
    46   using Quotient3_rel [OF assms]
    42   using Quotient3_rel [OF assms]
    47   apply (simp add: option_rel_def split: option.split)
    43   apply (simp add: option_rel_def split: option.split)
    48   done
    44   done
    49 
    45 
    50 declare [[mapQ3 option = (option_rel, option_quotient)]]
    46 declare [[mapQ3 option = (option_rel, option_quotient)]]
    59   shows "(R ===> option_rel R) Some Some"
    55   shows "(R ===> option_rel R) Some Some"
    60   by (rule Some_transfer)
    56   by (rule Some_transfer)
    61 
    57 
    62 lemma option_None_prs [quot_preserve]:
    58 lemma option_None_prs [quot_preserve]:
    63   assumes q: "Quotient3 R Abs Rep"
    59   assumes q: "Quotient3 R Abs Rep"
    64   shows "Option.map Abs None = None"
    60   shows "map_option Abs None = None"
    65   by simp
    61   by simp
    66 
    62 
    67 lemma option_Some_prs [quot_preserve]:
    63 lemma option_Some_prs [quot_preserve]:
    68   assumes q: "Quotient3 R Abs Rep"
    64   assumes q: "Quotient3 R Abs Rep"
    69   shows "(Rep ---> Option.map Abs) Some = Some"
    65   shows "(Rep ---> map_option Abs) Some = Some"
    70   apply(simp add: fun_eq_iff)
    66   apply(simp add: fun_eq_iff)
    71   apply(simp add: Quotient3_abs_rep[OF q])
    67   apply(simp add: Quotient3_abs_rep[OF q])
    72   done
    68   done
    73 
    69 
    74 end
    70 end