src/HOL/Lex/RegExp2NAe.thy
changeset 14440 3d6ed7eedfc8
parent 12792 b344226f924c
--- a/src/HOL/Lex/RegExp2NAe.thy	Fri Mar 05 15:30:49 2004 +0100
+++ b/src/HOL/Lex/RegExp2NAe.thy	Sat Mar 06 19:31:27 2004 +0100
@@ -7,20 +7,20 @@
 into nondeterministic automata with epsilon transitions
 *)
 
-RegExp2NAe = RegExp + NAe +
+theory RegExp2NAe = RegExp + NAe:
 
-types 'a bitsNAe = ('a,bool list)nae
+types 'a bitsNAe = "('a,bool list)nae"
 
-syntax "##" :: 'a => 'a list set => 'a list set (infixr 65)
+syntax "##" :: "'a => 'a list set => 'a list set" (infixr 65)
 translations "x ## S" == "Cons x ` S"
 
 constdefs
- atom  :: 'a => 'a bitsNAe
+ atom  :: "'a => 'a bitsNAe"
 "atom a == ([True],
             %b s. if s=[True] & b=Some a then {[False]} else {},
             %s. s=[False])"
 
- or :: 'a bitsNAe => 'a bitsNAe => 'a bitsNAe
+ or :: "'a bitsNAe => 'a bitsNAe => 'a bitsNAe"
 "or == %(ql,dl,fl)(qr,dr,fr).
    ([],
     %a s. case s of
@@ -29,7 +29,7 @@
                               else False ## dr a s,
     %s. case s of [] => False | left#s => if left then fl s else fr s)"
 
- conc :: 'a bitsNAe => 'a bitsNAe => 'a bitsNAe
+ conc :: "'a bitsNAe => 'a bitsNAe => 'a bitsNAe"
 "conc == %(ql,dl,fl)(qr,dr,fr).
    (True#ql,
     %a s. case s of
@@ -39,7 +39,7 @@
                               else False ## dr a s,
     %s. case s of [] => False | left#s => ~left & fr s)"
 
- star :: 'a bitsNAe => 'a bitsNAe
+ star :: "'a bitsNAe => 'a bitsNAe"
 "star == %(q,d,f).
    ([],
     %a s. case s of
@@ -49,7 +49,7 @@
                               else {},
     %s. case s of [] => True | left#s => left & f s)"
 
-consts rexp2nae :: 'a rexp => 'a bitsNAe
+consts rexp2nae :: "'a rexp => 'a bitsNAe"
 primrec
 "rexp2nae Empty      = ([], %a s. {}, %s. False)"
 "rexp2nae(Atom a)    = atom a"
@@ -57,4 +57,566 @@
 "rexp2nae(Conc r s)  = conc (rexp2nae r) (rexp2nae s)"
 "rexp2nae(Star r)    = star (rexp2nae r)"
 
+declare split_paired_all[simp]
+
+(******************************************************)
+(*                       atom                         *)
+(******************************************************)
+
+lemma fin_atom: "(fin (atom a) q) = (q = [False])"
+by(simp add:atom_def)
+
+lemma start_atom: "start (atom a) = [True]"
+by(simp add:atom_def)
+
+(* Use {x. False} = {}? *)
+
+lemma eps_atom[simp]:
+ "eps(atom a) = {}"
+by (simp add:atom_def step_def)
+
+lemma in_step_atom_Some[simp]:
+ "(p,q) : step (atom a) (Some b) = (p=[True] & q=[False] & b=a)"
+by (simp add:atom_def step_def)
+
+lemma False_False_in_steps_atom:
+  "([False],[False]) : steps (atom a) w = (w = [])"
+apply (induct "w")
+ apply (simp)
+apply (simp add: rel_comp_def)
+done
+
+lemma start_fin_in_steps_atom:
+  "(start (atom a), [False]) : steps (atom a) w = (w = [a])"
+apply (induct "w")
+ apply (simp add: start_atom rtrancl_empty)
+apply (simp add: False_False_in_steps_atom rel_comp_def start_atom)
+done
+
+lemma accepts_atom: "accepts (atom a) w = (w = [a])"
+by (simp add: accepts_def start_fin_in_steps_atom fin_atom)
+
+
+(******************************************************)
+(*                      or                            *)
+(******************************************************)
+
+(***** lift True/False over fin *****)
+
+lemma fin_or_True[iff]:
+ "!!L R. fin (or L R) (True#p) = fin L p"
+by(simp add:or_def)
+
+lemma fin_or_False[iff]:
+ "!!L R. fin (or L R) (False#p) = fin R p"
+by(simp add:or_def)
+
+(***** lift True/False over step *****)
+
+lemma True_in_step_or[iff]:
+"!!L R. (True#p,q) : step (or L R) a = (? r. q = True#r & (p,r) : step L a)"
+apply (simp add:or_def step_def)
+apply blast
+done
+
+lemma False_in_step_or[iff]:
+"!!L R. (False#p,q) : step (or L R) a = (? r. q = False#r & (p,r) : step R a)"
+apply (simp add:or_def step_def)
+apply blast
+done
+
+
+(***** lift True/False over epsclosure *****)
+
+lemma lemma1a:
+ "(tp,tq) : (eps(or L R))^* ==> 
+ (!!p. tp = True#p ==> ? q. (p,q) : (eps L)^* & tq = True#q)"
+apply (induct rule:rtrancl_induct)
+ apply (blast)
+apply (clarify)
+apply (simp)
+apply (blast intro: rtrancl_into_rtrancl)
+done
+
+lemma lemma1b:
+ "(tp,tq) : (eps(or L R))^* ==> 
+ (!!p. tp = False#p ==> ? q. (p,q) : (eps R)^* & tq = False#q)"
+apply (induct rule:rtrancl_induct)
+ apply (blast)
+apply (clarify)
+apply (simp)
+apply (blast intro: rtrancl_into_rtrancl)
+done
+
+lemma lemma2a:
+ "(p,q) : (eps L)^*  ==> (True#p, True#q) : (eps(or L R))^*"
+apply (induct rule: rtrancl_induct)
+ apply (blast)
+apply (blast intro: rtrancl_into_rtrancl)
+done
+
+lemma lemma2b:
+ "(p,q) : (eps R)^*  ==> (False#p, False#q) : (eps(or L R))^*"
+apply (induct rule: rtrancl_induct)
+ apply (blast)
+apply (blast intro: rtrancl_into_rtrancl)
+done
+
+lemma True_epsclosure_or[iff]:
+ "(True#p,q) : (eps(or L R))^* = (? r. q = True#r & (p,r) : (eps L)^*)"
+by (blast dest: lemma1a lemma2a)
+
+lemma False_epsclosure_or[iff]:
+ "(False#p,q) : (eps(or L R))^* = (? r. q = False#r & (p,r) : (eps R)^*)"
+by (blast dest: lemma1b lemma2b)
+
+(***** lift True/False over steps *****)
+
+lemma lift_True_over_steps_or[iff]:
+ "!!p. (True#p,q):steps (or L R) w = (? r. q = True # r & (p,r):steps L w)"
+apply (induct "w")
+ apply auto
+apply force
+done
+
+lemma lift_False_over_steps_or[iff]:
+ "!!p. (False#p,q):steps (or L R) w = (? r. q = False#r & (p,r):steps R w)"
+apply (induct "w")
+ apply auto
+apply (force)
+done
+
+(***** Epsilon closure of start state *****)
+
+lemma unfold_rtrancl2:
+ "R^* = Id Un (R^* O R)"
+apply (rule set_ext)
+apply (simp)
+apply (rule iffI)
+ apply (erule rtrancl_induct)
+  apply (blast)
+ apply (blast intro: rtrancl_into_rtrancl)
+apply (blast intro: converse_rtrancl_into_rtrancl)
+done
+
+lemma in_unfold_rtrancl2:
+ "(p,q) : R^* = (q = p | (? r. (p,r) : R & (r,q) : R^*))"
+apply (rule unfold_rtrancl2[THEN equalityE])
+apply (blast)
+done
+
+lemmas [iff] = in_unfold_rtrancl2[where p = "start(or L R)", standard]
+
+lemma start_eps_or[iff]:
+ "!!L R. (start(or L R),q) : eps(or L R) = 
+       (q = True#start L | q = False#start R)"
+by (simp add:or_def step_def)
+
+lemma not_start_step_or_Some[iff]:
+ "!!L R. (start(or L R),q) ~: step (or L R) (Some a)"
+by (simp add:or_def step_def)
+
+lemma steps_or:
+ "(start(or L R), q) : steps (or L R) w = 
+ ( (w = [] & q = start(or L R)) | 
+   (? p.  q = True  # p & (start L,p) : steps L w | 
+          q = False # p & (start R,p) : steps R w) )"
+apply (case_tac "w")
+ apply (simp)
+ apply (blast)
+apply (simp)
+apply (blast)
+done
+
+lemma start_or_not_final[iff]:
+ "!!L R. ~ fin (or L R) (start(or L R))"
+by (simp add:or_def)
+
+lemma accepts_or:
+ "accepts (or L R) w = (accepts L w | accepts R w)"
+apply (simp add:accepts_def steps_or)
+ apply auto
+done
+
+
+(******************************************************)
+(*                      conc                          *)
+(******************************************************)
+
+(** True/False in fin **)
+
+lemma in_conc_True[iff]:
+ "!!L R. fin (conc L R) (True#p) = False"
+by (simp add:conc_def)
+
+lemma fin_conc_False[iff]:
+ "!!L R. fin (conc L R) (False#p) = fin R p"
+by (simp add:conc_def)
+
+(** True/False in step **)
+
+lemma True_step_conc[iff]:
+ "!!L R. (True#p,q) : step (conc L R) a = 
+       ((? r. q=True#r & (p,r): step L a) | 
+        (fin L p & a=None & q=False#start R))"
+by (simp add:conc_def step_def) (blast)
+
+lemma False_step_conc[iff]:
+ "!!L R. (False#p,q) : step (conc L R) a = 
+       (? r. q = False#r & (p,r) : step R a)"
+by (simp add:conc_def step_def) (blast)
+
+(** False in epsclosure **)
+
+lemma lemma1b:
+ "(tp,tq) : (eps(conc L R))^* ==> 
+  (!!p. tp = False#p ==> ? q. (p,q) : (eps R)^* & tq = False#q)"
+apply (induct rule: rtrancl_induct)
+ apply (blast)
+apply (blast intro: rtrancl_into_rtrancl)
+done
+
+lemma lemma2b:
+ "(p,q) : (eps R)^* ==> (False#p, False#q) : (eps(conc L R))^*"
+apply (induct rule: rtrancl_induct)
+ apply (blast)
+apply (blast intro: rtrancl_into_rtrancl)
+done
+
+lemma False_epsclosure_conc[iff]:
+ "((False # p, q) : (eps (conc L R))^*) = 
+ (? r. q = False # r & (p, r) : (eps R)^*)"
+apply (rule iffI)
+ apply (blast dest: lemma1b)
+apply (blast dest: lemma2b)
+done
+
+(** False in steps **)
+
+lemma False_steps_conc[iff]:
+ "!!p. (False#p,q): steps (conc L R) w = (? r. q=False#r & (p,r): steps R w)"
+apply (induct "w")
+ apply (simp)
+apply (simp)
+apply (fast)  (*MUCH faster than blast*)
+done
+
+(** True in epsclosure **)
+
+lemma True_True_eps_concI:
+ "(p,q): (eps L)^* ==> (True#p,True#q) : (eps(conc L R))^*"
+apply (induct rule: rtrancl_induct)
+ apply (blast)
+apply (blast intro: rtrancl_into_rtrancl)
+done
+
+lemma True_True_steps_concI:
+ "!!p. (p,q) : steps L w ==> (True#p,True#q) : steps (conc L R) w"
+apply (induct "w")
+ apply (simp add: True_True_eps_concI)
+apply (simp)
+apply (blast intro: True_True_eps_concI)
+done
+
+lemma lemma1a:
+ "(tp,tq) : (eps(conc L R))^* ==> 
+ (!!p. tp = True#p ==> 
+  (? q. tq = True#q & (p,q) : (eps L)^*) | 
+  (? q r. tq = False#q & (p,r):(eps L)^* & fin L r & (start R,q) : (eps R)^*))"
+apply (induct rule: rtrancl_induct)
+ apply (blast)
+apply (blast intro: rtrancl_into_rtrancl)
+done
+
+lemma lemma2a:
+ "(p, q) : (eps L)^* ==> (True#p, True#q) : (eps(conc L R))^*"
+apply (induct rule: rtrancl_induct)
+ apply (blast)
+apply (blast intro: rtrancl_into_rtrancl)
+done
+
+lemma lem:
+ "!!L R. (p,q) : step R None ==> (False#p, False#q) : step (conc L R) None"
+by(simp add: conc_def step_def)
+
+lemma lemma2b:
+ "(p,q) : (eps R)^* ==> (False#p, False#q) : (eps(conc L R))^*"
+apply (induct rule: rtrancl_induct)
+ apply (blast)
+apply (drule lem)
+apply (blast intro: rtrancl_into_rtrancl)
+done
+
+lemma True_False_eps_concI:
+ "!!L R. fin L p ==> (True#p, False#start R) : eps(conc L R)"
+by(simp add: conc_def step_def)
+
+lemma True_epsclosure_conc[iff]:
+ "((True#p,q) : (eps(conc L R))^*) = 
+ ((? r. (p,r) : (eps L)^* & q = True#r) | 
+  (? r. (p,r) : (eps L)^* & fin L r & 
+        (? s. (start R, s) : (eps R)^* & q = False#s)))"
+apply (rule iffI)
+ apply (blast dest: lemma1a)
+apply (erule disjE)
+ apply (blast intro: lemma2a)
+apply (clarify)
+apply (rule rtrancl_trans)
+apply (erule lemma2a)
+apply (rule converse_rtrancl_into_rtrancl)
+apply (erule True_False_eps_concI)
+apply (erule lemma2b)
+done
+
+(** True in steps **)
+
+lemma True_steps_concD[rule_format]:
+ "!p. (True#p,q) : steps (conc L R) w --> 
+     ((? r. (p,r) : steps L w & q = True#r)  | 
+      (? u v. w = u@v & (? r. (p,r) : steps L u & fin L r & 
+              (? s. (start R,s) : steps R v & q = False#s))))"
+apply (induct "w")
+ apply (simp)
+apply (simp)
+apply (clarify del: disjCI)
+ apply (erule disjE)
+ apply (clarify del: disjCI)
+ apply (erule disjE)
+  apply (clarify del: disjCI)
+  apply (erule allE, erule impE, assumption)
+  apply (erule disjE)
+   apply (blast)
+  apply (rule disjI2)
+  apply (clarify)
+  apply (simp)
+  apply (rule_tac x = "a#u" in exI)
+  apply (simp)
+  apply (blast)
+ apply (blast)
+apply (rule disjI2)
+apply (clarify)
+apply (simp)
+apply (rule_tac x = "[]" in exI)
+apply (simp)
+apply (blast)
+done
+
+lemma True_steps_conc:
+ "(True#p,q) : steps (conc L R) w = 
+ ((? r. (p,r) : steps L w & q = True#r)  | 
+  (? u v. w = u@v & (? r. (p,r) : steps L u & fin L r & 
+          (? s. (start R,s) : steps R v & q = False#s))))"
+by (blast dest: True_steps_concD
+    intro: True_True_steps_concI in_steps_epsclosure)
+
+(** starting from the start **)
+
+lemma start_conc:
+  "!!L R. start(conc L R) = True#start L"
+by (simp add: conc_def)
+
+lemma final_conc:
+ "!!L R. fin(conc L R) p = (? s. p = False#s & fin R s)"
+by (simp add:conc_def split: list.split)
+
+lemma accepts_conc:
+ "accepts (conc L R) w = (? u v. w = u@v & accepts L u & accepts R v)"
+apply (simp add: accepts_def True_steps_conc final_conc start_conc)
+apply (blast)
+done
+
+(******************************************************)
+(*                       star                         *)
+(******************************************************)
+
+lemma True_in_eps_star[iff]:
+ "!!A. (True#p,q) : eps(star A) = 
+     ( (? r. q = True#r & (p,r) : eps A) | (fin A p & q = True#start A) )"
+by (simp add:star_def step_def) (blast)
+
+lemma True_True_step_starI:
+  "!!A. (p,q) : step A a ==> (True#p, True#q) : step (star A) a"
+by (simp add:star_def step_def)
+
+lemma True_True_eps_starI:
+  "(p,r) : (eps A)^* ==> (True#p, True#r) : (eps(star A))^*"
+apply (induct rule: rtrancl_induct)
+ apply (blast)
+apply (blast intro: True_True_step_starI rtrancl_into_rtrancl)
+done
+
+lemma True_start_eps_starI:
+ "!!A. fin A p ==> (True#p,True#start A) : eps(star A)"
+by (simp add:star_def step_def)
+
+lemma lem:
+ "(tp,s) : (eps(star A))^* ==> (! p. tp = True#p --> 
+ (? r. ((p,r) : (eps A)^* | 
+        (? q. (p,q) : (eps A)^* & fin A q & (start A,r) : (eps A)^*)) & 
+       s = True#r))"
+apply (induct rule: rtrancl_induct)
+ apply (simp)
+apply (clarify)
+apply (simp)
+apply (blast intro: rtrancl_into_rtrancl)
+done
+
+lemma True_eps_star[iff]:
+ "((True#p,s) : (eps(star A))^*) = 
+ (? r. ((p,r) : (eps A)^* | 
+        (? q. (p,q) : (eps A)^* & fin A q & (start A,r) : (eps A)^*)) & 
+       s = True#r)"
+apply (rule iffI)
+ apply (drule lem)
+ apply (blast)
+(* Why can't blast do the rest? *)
+apply (clarify)
+apply (erule disjE)
+apply (erule True_True_eps_starI)
+apply (clarify)
+apply (rule rtrancl_trans)
+apply (erule True_True_eps_starI)
+apply (rule rtrancl_trans)
+apply (rule r_into_rtrancl)
+apply (erule True_start_eps_starI)
+apply (erule True_True_eps_starI)
+done
+
+(** True in step Some **)
+
+lemma True_step_star[iff]:
+ "!!A. (True#p,r): step (star A) (Some a) = 
+     (? q. (p,q): step A (Some a) & r=True#q)"
+by (simp add:star_def step_def) (blast)
+
+
+(** True in steps **)
+
+(* reverse list induction! Complicates matters for conc? *)
+lemma True_start_steps_starD[rule_format]:
+ "!rr. (True#start A,rr) : steps (star A) w --> 
+ (? us v. w = concat us @ v & 
+             (!u:set us. accepts A u) & 
+             (? r. (start A,r) : steps A v & rr = True#r))"
+apply (induct w rule: rev_induct)
+ apply (simp)
+ apply (clarify)
+ apply (rule_tac x = "[]" in exI)
+ apply (erule disjE)
+  apply (simp)
+ apply (clarify)
+ apply (simp)
+apply (simp add: O_assoc epsclosure_steps)
+apply (clarify)
+apply (erule allE, erule impE, assumption)
+apply (clarify)
+apply (erule disjE)
+ apply (rule_tac x = "us" in exI)
+ apply (rule_tac x = "v@[x]" in exI)
+ apply (simp add: O_assoc epsclosure_steps)
+ apply (blast)
+apply (clarify)
+apply (rule_tac x = "us@[v@[x]]" in exI)
+apply (rule_tac x = "[]" in exI)
+apply (simp add: accepts_def)
+apply (blast)
+done
+
+lemma True_True_steps_starI:
+  "!!p. (p,q) : steps A w ==> (True#p,True#q) : steps (star A) w"
+apply (induct "w")
+ apply (simp)
+apply (simp)
+apply (blast intro: True_True_eps_starI True_True_step_starI)
+done
+
+lemma steps_star_cycle:
+ "(!u : set us. accepts A u) ==> 
+ (True#start A,True#start A) : steps (star A) (concat us)"
+apply (induct "us")
+ apply (simp add:accepts_def)
+apply (simp add:accepts_def)
+by(blast intro: True_True_steps_starI True_start_eps_starI in_epsclosure_steps)
+
+(* Better stated directly with start(star A)? Loop in star A back to start(star A)?*)
+lemma True_start_steps_star:
+ "(True#start A,rr) : steps (star A) w = 
+ (? us v. w = concat us @ v & 
+             (!u:set us. accepts A u) & 
+             (? r. (start A,r) : steps A v & rr = True#r))"
+apply (rule iffI)
+ apply (erule True_start_steps_starD)
+apply (clarify)
+apply (blast intro: steps_star_cycle True_True_steps_starI)
+done
+
+(** the start state **)
+
+lemma start_step_star[iff]:
+  "!!A. (start(star A),r) : step (star A) a = (a=None & r = True#start A)"
+by (simp add:star_def step_def)
+
+lemmas epsclosure_start_step_star =
+  in_unfold_rtrancl2[where p = "start(star A)", standard]
+
+lemma start_steps_star:
+ "(start(star A),r) : steps (star A) w = 
+ ((w=[] & r= start(star A)) | (True#start A,r) : steps (star A) w)"
+apply (rule iffI)
+ apply (case_tac "w")
+  apply (simp add: epsclosure_start_step_star)
+ apply (simp)
+ apply (clarify)
+ apply (simp add: epsclosure_start_step_star)
+ apply (blast)
+apply (erule disjE)
+ apply (simp)
+apply (blast intro: in_steps_epsclosure)
+done
+
+lemma fin_star_True[iff]: "!!A. fin (star A) (True#p) = fin A p"
+by (simp add:star_def)
+
+lemma fin_star_start[iff]: "!!A. fin (star A) (start(star A))"
+by (simp add:star_def)
+
+(* too complex! Simpler if loop back to start(star A)? *)
+lemma accepts_star:
+ "accepts (star A) w = 
+ (? us. (!u : set(us). accepts A u) & (w = concat us) )"
+apply(unfold accepts_def)
+apply (simp add: start_steps_star True_start_steps_star)
+apply (rule iffI)
+ apply (clarify)
+ apply (erule disjE)
+  apply (clarify)
+  apply (simp)
+  apply (rule_tac x = "[]" in exI)
+  apply (simp)
+ apply (clarify)
+ apply (rule_tac x = "us@[v]" in exI)
+ apply (simp add: accepts_def)
+ apply (blast)
+apply (clarify)
+apply (rule_tac xs = "us" in rev_exhaust)
+ apply (simp)
+ apply (blast)
+apply (clarify)
+apply (simp add: accepts_def)
+apply (blast)
+done
+
+
+(***** Correctness of r2n *****)
+
+lemma accepts_rexp2nae:
+ "!!w. accepts (rexp2nae r) w = (w : lang r)"
+apply (induct "r")
+    apply (simp add: accepts_def)
+   apply (simp add: accepts_atom)
+  apply (simp add: accepts_or)
+ apply (simp add: accepts_conc RegSet.conc_def)
+apply (simp add: accepts_star in_star)
+done
+
 end