diff -r e67760c1b851 -r 7ffdbc24b27f src/HOLCF/ex/Stream.thy --- a/src/HOLCF/ex/Stream.thy Mon May 24 11:29:49 2010 -0700 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,965 +0,0 @@ -(* Title: HOLCF/ex/Stream.thy - Author: Franz Regensburger, David von Oheimb, Borislav Gajanovic -*) - -header {* General Stream domain *} - -theory Stream -imports HOLCF Nat_Infinity -begin - -domain 'a stream = scons (ft::'a) (lazy rt::"'a stream") (infixr "&&" 65) - -definition - smap :: "('a \ 'b) \ 'a stream \ 'b stream" where - "smap = fix\(\ h f s. case s of x && xs \ f\x && h\f\xs)" - -definition - sfilter :: "('a \ tr) \ 'a stream \ 'a stream" where - "sfilter = fix\(\ h p s. case s of x && xs \ - If p\x then x && h\p\xs else h\p\xs fi)" - -definition - slen :: "'a stream \ inat" ("#_" [1000] 1000) where - "#s = (if stream_finite s then Fin (LEAST n. stream_take n\s = s) else \)" - - -(* concatenation *) - -definition - i_rt :: "nat => 'a stream => 'a stream" where (* chops the first i elements *) - "i_rt = (%i s. iterate i$rt$s)" - -definition - i_th :: "nat => 'a stream => 'a" where (* the i-th element *) - "i_th = (%i s. ft$(i_rt i s))" - -definition - sconc :: "'a stream => 'a stream => 'a stream" (infixr "ooo" 65) where - "s1 ooo s2 = (case #s1 of - Fin n \ (SOME s. (stream_take n$s=s1) & (i_rt n s = s2)) - | \ \ s1)" - -primrec constr_sconc' :: "nat => 'a stream => 'a stream => 'a stream" -where - constr_sconc'_0: "constr_sconc' 0 s1 s2 = s2" -| constr_sconc'_Suc: "constr_sconc' (Suc n) s1 s2 = ft$s1 && - constr_sconc' n (rt$s1) s2" - -definition - constr_sconc :: "'a stream => 'a stream => 'a stream" where (* constructive *) - "constr_sconc s1 s2 = (case #s1 of - Fin n \ constr_sconc' n s1 s2 - | \ \ s1)" - - -(* ----------------------------------------------------------------------- *) -(* theorems about scons *) -(* ----------------------------------------------------------------------- *) - - -section "scons" - -lemma scons_eq_UU: "(a && s = UU) = (a = UU)" -by simp - -lemma scons_not_empty: "[| a && x = UU; a ~= UU |] ==> R" -by simp - -lemma stream_exhaust_eq: "(x ~= UU) = (EX a y. a ~= UU & x = a && y)" -by (cases x, auto) - -lemma stream_neq_UU: "x~=UU ==> EX a a_s. x=a&&a_s & a~=UU" -by (simp add: stream_exhaust_eq,auto) - -lemma stream_prefix: - "[| a && s << t; a ~= UU |] ==> EX b tt. t = b && tt & b ~= UU & s << tt" -by (cases t, auto) - -lemma stream_prefix': - "b ~= UU ==> x << b && z = - (x = UU | (EX a y. x = a && y & a ~= UU & a << b & y << z))" -by (cases x, auto) - - -(* -lemma stream_prefix1: "[| x< x&&xs << y&&ys" -by (insert stream_prefix' [of y "x&&xs" ys],force) -*) - -lemma stream_flat_prefix: - "[| x && xs << y && ys; (x::'a::flat) ~= UU|] ==> x = y & xs << ys" -apply (case_tac "y=UU",auto) -by (drule ax_flat,simp) - - - - -(* ----------------------------------------------------------------------- *) -(* theorems about stream_when *) -(* ----------------------------------------------------------------------- *) - -section "stream_when" - - -lemma stream_when_strictf: "stream_when$UU$s=UU" -by (cases s, auto) - - - -(* ----------------------------------------------------------------------- *) -(* theorems about ft and rt *) -(* ----------------------------------------------------------------------- *) - - -section "ft & rt" - - -lemma ft_defin: "s~=UU ==> ft$s~=UU" -by simp - -lemma rt_strict_rev: "rt$s~=UU ==> s~=UU" -by auto - -lemma surjectiv_scons: "(ft$s)&&(rt$s)=s" -by (cases s, auto) - -lemma monofun_rt_mult: "x << s ==> iterate i$rt$x << iterate i$rt$s" -by (rule monofun_cfun_arg) - - - -(* ----------------------------------------------------------------------- *) -(* theorems about stream_take *) -(* ----------------------------------------------------------------------- *) - - -section "stream_take" - - -lemma stream_reach2: "(LUB i. stream_take i$s) = s" -by (rule stream.reach) - -lemma chain_stream_take: "chain (%i. stream_take i$s)" -by simp - -lemma stream_take_prefix [simp]: "stream_take n$s << s" -apply (insert stream_reach2 [of s]) -apply (erule subst) back -apply (rule is_ub_thelub) -by (simp only: chain_stream_take) - -lemma stream_take_more [rule_format]: - "ALL x. stream_take n$x = x --> stream_take (Suc n)$x = x" -apply (induct_tac n,auto) -apply (case_tac "x=UU",auto) -by (drule stream_exhaust_eq [THEN iffD1],auto) - -lemma stream_take_lemma3 [rule_format]: - "ALL x xs. x~=UU --> stream_take n$(x && xs) = x && xs --> stream_take n$xs=xs" -apply (induct_tac n,clarsimp) -(*apply (drule sym, erule scons_not_empty, simp)*) -apply (clarify, rule stream_take_more) -apply (erule_tac x="x" in allE) -by (erule_tac x="xs" in allE,simp) - -lemma stream_take_lemma4: - "ALL x xs. stream_take n$xs=xs --> stream_take (Suc n)$(x && xs) = x && xs" -by auto - -lemma stream_take_idempotent [rule_format, simp]: - "ALL s. stream_take n$(stream_take n$s) = stream_take n$s" -apply (induct_tac n, auto) -apply (case_tac "s=UU", auto) -by (drule stream_exhaust_eq [THEN iffD1], auto) - -lemma stream_take_take_Suc [rule_format, simp]: - "ALL s. stream_take n$(stream_take (Suc n)$s) = - stream_take n$s" -apply (induct_tac n, auto) -apply (case_tac "s=UU", auto) -by (drule stream_exhaust_eq [THEN iffD1], auto) - -lemma mono_stream_take_pred: - "stream_take (Suc n)$s1 << stream_take (Suc n)$s2 ==> - stream_take n$s1 << stream_take n$s2" -by (insert monofun_cfun_arg [of "stream_take (Suc n)$s1" - "stream_take (Suc n)$s2" "stream_take n"], auto) -(* -lemma mono_stream_take_pred: - "stream_take (Suc n)$s1 << stream_take (Suc n)$s2 ==> - stream_take n$s1 << stream_take n$s2" -by (drule mono_stream_take [of _ _ n],simp) -*) - -lemma stream_take_lemma10 [rule_format]: - "ALL k<=n. stream_take n$s1 << stream_take n$s2 - --> stream_take k$s1 << stream_take k$s2" -apply (induct_tac n,simp,clarsimp) -apply (case_tac "k=Suc n",blast) -apply (erule_tac x="k" in allE) -by (drule mono_stream_take_pred,simp) - -lemma stream_take_le_mono : "k<=n ==> stream_take k$s1 << stream_take n$s1" -apply (insert chain_stream_take [of s1]) -by (drule chain_mono,auto) - -lemma mono_stream_take: "s1 << s2 ==> stream_take n$s1 << stream_take n$s2" -by (simp add: monofun_cfun_arg) - -(* -lemma stream_take_prefix [simp]: "stream_take n$s << s" -apply (subgoal_tac "s=(LUB n. stream_take n$s)") - apply (erule ssubst, rule is_ub_thelub) - apply (simp only: chain_stream_take) -by (simp only: stream_reach2) -*) - -lemma stream_take_take_less:"stream_take k$(stream_take n$s) << stream_take k$s" -by (rule monofun_cfun_arg,auto) - - -(* ------------------------------------------------------------------------- *) -(* special induction rules *) -(* ------------------------------------------------------------------------- *) - - -section "induction" - -lemma stream_finite_ind: - "[| stream_finite x; P UU; !!a s. [| a ~= UU; P s |] ==> P (a && s) |] ==> P x" -apply (simp add: stream.finite_def,auto) -apply (erule subst) -by (drule stream.finite_induct [of P _ x], auto) - -lemma stream_finite_ind2: -"[| P UU; !! x. x ~= UU ==> P (x && UU); !! y z s. [| y ~= UU; z ~= UU; P s |] ==> P (y && z && s )|] ==> - !s. P (stream_take n$s)" -apply (rule nat_less_induct [of _ n],auto) -apply (case_tac n, auto) -apply (case_tac nat, auto) -apply (case_tac "s=UU",clarsimp) -apply (drule stream_exhaust_eq [THEN iffD1],clarsimp) -apply (case_tac "s=UU",clarsimp) -apply (drule stream_exhaust_eq [THEN iffD1],clarsimp) -apply (case_tac "y=UU",clarsimp) -by (drule stream_exhaust_eq [THEN iffD1],clarsimp) - -lemma stream_ind2: -"[| adm P; P UU; !!a. a ~= UU ==> P (a && UU); !!a b s. [| a ~= UU; b ~= UU; P s |] ==> P (a && b && s) |] ==> P x" -apply (insert stream.reach [of x],erule subst) -apply (erule admD, rule chain_stream_take) -apply (insert stream_finite_ind2 [of P]) -by simp - - - -(* ----------------------------------------------------------------------- *) -(* simplify use of coinduction *) -(* ----------------------------------------------------------------------- *) - - -section "coinduction" - -lemma stream_coind_lemma2: "!s1 s2. R s1 s2 --> ft$s1 = ft$s2 & R (rt$s1) (rt$s2) ==> stream_bisim R" - apply (simp add: stream.bisim_def,clarsimp) - apply (drule spec, drule spec, drule (1) mp) - apply (case_tac "x", simp) - apply (case_tac "x'", simp) -by auto - - - -(* ----------------------------------------------------------------------- *) -(* theorems about stream_finite *) -(* ----------------------------------------------------------------------- *) - - -section "stream_finite" - -lemma stream_finite_UU [simp]: "stream_finite UU" -by (simp add: stream.finite_def) - -lemma stream_finite_UU_rev: "~ stream_finite s ==> s ~= UU" -by (auto simp add: stream.finite_def) - -lemma stream_finite_lemma1: "stream_finite xs ==> stream_finite (x && xs)" -apply (simp add: stream.finite_def,auto) -apply (rule_tac x="Suc n" in exI) -by (simp add: stream_take_lemma4) - -lemma stream_finite_lemma2: "[| x ~= UU; stream_finite (x && xs) |] ==> stream_finite xs" -apply (simp add: stream.finite_def, auto) -apply (rule_tac x="n" in exI) -by (erule stream_take_lemma3,simp) - -lemma stream_finite_rt_eq: "stream_finite (rt$s) = stream_finite s" -apply (cases s, auto) -apply (rule stream_finite_lemma1, simp) -by (rule stream_finite_lemma2,simp) - -lemma stream_finite_less: "stream_finite s ==> !t. t< stream_finite t" -apply (erule stream_finite_ind [of s], auto) -apply (case_tac "t=UU", auto) -apply (drule stream_exhaust_eq [THEN iffD1],auto) -apply (erule_tac x="y" in allE, simp) -by (rule stream_finite_lemma1, simp) - -lemma stream_take_finite [simp]: "stream_finite (stream_take n$s)" -apply (simp add: stream.finite_def) -by (rule_tac x="n" in exI,simp) - -lemma adm_not_stream_finite: "adm (%x. ~ stream_finite x)" -apply (rule adm_upward) -apply (erule contrapos_nn) -apply (erule (1) stream_finite_less [rule_format]) -done - - - -(* ----------------------------------------------------------------------- *) -(* theorems about stream length *) -(* ----------------------------------------------------------------------- *) - - -section "slen" - -lemma slen_empty [simp]: "#\ = 0" -by (simp add: slen_def stream.finite_def zero_inat_def Least_equality) - -lemma slen_scons [simp]: "x ~= \ ==> #(x&&xs) = iSuc (#xs)" -apply (case_tac "stream_finite (x && xs)") -apply (simp add: slen_def, auto) -apply (simp add: stream.finite_def, auto simp add: iSuc_Fin) -apply (rule Least_Suc2, auto) -(*apply (drule sym)*) -(*apply (drule sym scons_eq_UU [THEN iffD1],simp)*) -apply (erule stream_finite_lemma2, simp) -apply (simp add: slen_def, auto) -by (drule stream_finite_lemma1,auto) - -lemma slen_less_1_eq: "(#x < Fin (Suc 0)) = (x = \)" -by (cases x, auto simp add: Fin_0 iSuc_Fin[THEN sym]) - -lemma slen_empty_eq: "(#x = 0) = (x = \)" -by (cases x, auto) - -lemma slen_scons_eq: "(Fin (Suc n) < #x) = (? a y. x = a && y & a ~= \ & Fin n < #y)" -apply (auto, case_tac "x=UU",auto) -apply (drule stream_exhaust_eq [THEN iffD1], auto) -apply (case_tac "#y") apply simp_all -apply (case_tac "#y") apply simp_all -done - -lemma slen_iSuc: "#x = iSuc n --> (? a y. x = a&&y & a ~= \ & #y = n)" -by (cases x, auto) - -lemma slen_stream_take_finite [simp]: "#(stream_take n$s) ~= \" -by (simp add: slen_def) - -lemma slen_scons_eq_rev: "(#x < Fin (Suc (Suc n))) = (!a y. x ~= a && y | a = \ | #y < Fin (Suc n))" - apply (cases x, auto) - apply (simp add: zero_inat_def) - apply (case_tac "#stream") apply (simp_all add: iSuc_Fin) - apply (case_tac "#stream") apply (simp_all add: iSuc_Fin) -done - -lemma slen_take_lemma4 [rule_format]: - "!s. stream_take n$s ~= s --> #(stream_take n$s) = Fin n" -apply (induct n, auto simp add: Fin_0) -apply (case_tac "s=UU", simp) -by (drule stream_exhaust_eq [THEN iffD1], auto simp add: iSuc_Fin) - -(* -lemma stream_take_idempotent [simp]: - "stream_take n$(stream_take n$s) = stream_take n$s" -apply (case_tac "stream_take n$s = s") -apply (auto,insert slen_take_lemma4 [of n s]); -by (auto,insert slen_take_lemma1 [of "stream_take n$s" n],simp) - -lemma stream_take_take_Suc [simp]: "stream_take n$(stream_take (Suc n)$s) = - stream_take n$s" -apply (simp add: po_eq_conv,auto) - apply (simp add: stream_take_take_less) -apply (subgoal_tac "stream_take n$s = stream_take n$(stream_take n$s)") - apply (erule ssubst) - apply (rule_tac monofun_cfun_arg) - apply (insert chain_stream_take [of s]) -by (simp add: chain_def,simp) -*) - -lemma slen_take_eq: "ALL x. (Fin n < #x) = (stream_take n\x ~= x)" -apply (induct_tac n, auto) -apply (simp add: Fin_0, clarsimp) -apply (drule not_sym) -apply (drule slen_empty_eq [THEN iffD1], simp) -apply (case_tac "x=UU", simp) -apply (drule stream_exhaust_eq [THEN iffD1], clarsimp) -apply (erule_tac x="y" in allE, auto) -apply (simp_all add: not_less iSuc_Fin) -apply (case_tac "#y") apply simp_all -apply (case_tac "x=UU", simp) -apply (drule stream_exhaust_eq [THEN iffD1], clarsimp) -apply (erule_tac x="y" in allE, simp) -apply (case_tac "#y") by simp_all - -lemma slen_take_eq_rev: "(#x <= Fin n) = (stream_take n\x = x)" -by (simp add: linorder_not_less [symmetric] slen_take_eq) - -lemma slen_take_lemma1: "#x = Fin n ==> stream_take n\x = x" -by (rule slen_take_eq_rev [THEN iffD1], auto) - -lemma slen_rt_mono: "#s2 <= #s1 ==> #(rt$s2) <= #(rt$s1)" -apply (cases s1) - by (cases s2, simp+)+ - -lemma slen_take_lemma5: "#(stream_take n$s) <= Fin n" -apply (case_tac "stream_take n$s = s") - apply (simp add: slen_take_eq_rev) -by (simp add: slen_take_lemma4) - -lemma slen_take_lemma2: "!x. ~stream_finite x --> #(stream_take i\x) = Fin i" -apply (simp add: stream.finite_def, auto) -by (simp add: slen_take_lemma4) - -lemma slen_infinite: "stream_finite x = (#x ~= Infty)" -by (simp add: slen_def) - -lemma slen_mono_lemma: "stream_finite s ==> ALL t. s << t --> #s <= #t" -apply (erule stream_finite_ind [of s], auto) -apply (case_tac "t=UU", auto) -apply (drule stream_exhaust_eq [THEN iffD1], auto) -done - -lemma slen_mono: "s << t ==> #s <= #t" -apply (case_tac "stream_finite t") -apply (frule stream_finite_less) -apply (erule_tac x="s" in allE, simp) -apply (drule slen_mono_lemma, auto) -by (simp add: slen_def) - -lemma iterate_lemma: "F$(iterate n$F$x) = iterate n$F$(F$x)" -by (insert iterate_Suc2 [of n F x], auto) - -lemma slen_rt_mult [rule_format]: "!x. Fin (i + j) <= #x --> Fin j <= #(iterate i$rt$x)" -apply (induct i, auto) -apply (case_tac "x=UU", auto simp add: zero_inat_def) -apply (drule stream_exhaust_eq [THEN iffD1], auto) -apply (erule_tac x="y" in allE, auto) -apply (simp add: not_le) apply (case_tac "#y") apply (simp_all add: iSuc_Fin) -by (simp add: iterate_lemma) - -lemma slen_take_lemma3 [rule_format]: - "!(x::'a::flat stream) y. Fin n <= #x --> x << y --> stream_take n\x = stream_take n\y" -apply (induct_tac n, auto) -apply (case_tac "x=UU", auto) -apply (simp add: zero_inat_def) -apply (simp add: Suc_ile_eq) -apply (case_tac "y=UU", clarsimp) -apply (drule stream_exhaust_eq [THEN iffD1], clarsimp)+ -apply (erule_tac x="ya" in allE, simp) -by (drule ax_flat, simp) - -lemma slen_strict_mono_lemma: - "stream_finite t ==> !s. #(s::'a::flat stream) = #t & s << t --> s = t" -apply (erule stream_finite_ind, auto) -apply (case_tac "sa=UU", auto) -apply (drule stream_exhaust_eq [THEN iffD1], clarsimp) -by (drule ax_flat, simp) - -lemma slen_strict_mono: "[|stream_finite t; s ~= t; s << (t::'a::flat stream) |] ==> #s < #t" -by (auto simp add: slen_mono less_le dest: slen_strict_mono_lemma) - -lemma stream_take_Suc_neq: "stream_take (Suc n)$s ~=s ==> - stream_take n$s ~= stream_take (Suc n)$s" -apply auto -apply (subgoal_tac "stream_take n$s ~=s") - apply (insert slen_take_lemma4 [of n s],auto) -apply (cases s, simp) -by (simp add: slen_take_lemma4 iSuc_Fin) - -(* ----------------------------------------------------------------------- *) -(* theorems about smap *) -(* ----------------------------------------------------------------------- *) - - -section "smap" - -lemma smap_unfold: "smap = (\ f t. case t of x&&xs \ f$x && smap$f$xs)" -by (insert smap_def [where 'a='a and 'b='b, THEN eq_reflection, THEN fix_eq2], auto) - -lemma smap_empty [simp]: "smap\f\\ = \" -by (subst smap_unfold, simp) - -lemma smap_scons [simp]: "x~=\ ==> smap\f\(x&&xs) = (f\x)&&(smap\f\xs)" -by (subst smap_unfold, force) - - - -(* ----------------------------------------------------------------------- *) -(* theorems about sfilter *) -(* ----------------------------------------------------------------------- *) - -section "sfilter" - -lemma sfilter_unfold: - "sfilter = (\ p s. case s of x && xs \ - If p\x then x && sfilter\p\xs else sfilter\p\xs fi)" -by (insert sfilter_def [where 'a='a, THEN eq_reflection, THEN fix_eq2], auto) - -lemma strict_sfilter: "sfilter\\ = \" -apply (rule ext_cfun) -apply (subst sfilter_unfold, auto) -apply (case_tac "x=UU", auto) -by (drule stream_exhaust_eq [THEN iffD1], auto) - -lemma sfilter_empty [simp]: "sfilter\f\\ = \" -by (subst sfilter_unfold, force) - -lemma sfilter_scons [simp]: - "x ~= \ ==> sfilter\f\(x && xs) = - If f\x then x && sfilter\f\xs else sfilter\f\xs fi" -by (subst sfilter_unfold, force) - - -(* ----------------------------------------------------------------------- *) - section "i_rt" -(* ----------------------------------------------------------------------- *) - -lemma i_rt_UU [simp]: "i_rt n UU = UU" - by (induct n) (simp_all add: i_rt_def) - -lemma i_rt_0 [simp]: "i_rt 0 s = s" -by (simp add: i_rt_def) - -lemma i_rt_Suc [simp]: "a ~= UU ==> i_rt (Suc n) (a&&s) = i_rt n s" -by (simp add: i_rt_def iterate_Suc2 del: iterate_Suc) - -lemma i_rt_Suc_forw: "i_rt (Suc n) s = i_rt n (rt$s)" -by (simp only: i_rt_def iterate_Suc2) - -lemma i_rt_Suc_back:"i_rt (Suc n) s = rt$(i_rt n s)" -by (simp only: i_rt_def,auto) - -lemma i_rt_mono: "x << s ==> i_rt n x << i_rt n s" -by (simp add: i_rt_def monofun_rt_mult) - -lemma i_rt_ij_lemma: "Fin (i + j) <= #x ==> Fin j <= #(i_rt i x)" -by (simp add: i_rt_def slen_rt_mult) - -lemma slen_i_rt_mono: "#s2 <= #s1 ==> #(i_rt n s2) <= #(i_rt n s1)" -apply (induct_tac n,auto) -apply (simp add: i_rt_Suc_back) -by (drule slen_rt_mono,simp) - -lemma i_rt_take_lemma1 [rule_format]: "ALL s. i_rt n (stream_take n$s) = UU" -apply (induct_tac n) - apply (simp add: i_rt_Suc_back,auto) -apply (case_tac "s=UU",auto) -by (drule stream_exhaust_eq [THEN iffD1],auto) - -lemma i_rt_slen: "(i_rt n s = UU) = (stream_take n$s = s)" -apply auto - apply (insert i_rt_ij_lemma [of n "Suc 0" s]) - apply (subgoal_tac "#(i_rt n s)=0") - apply (case_tac "stream_take n$s = s",simp+) - apply (insert slen_take_eq [rule_format,of n s],simp) - apply (cases "#s") apply (simp_all add: zero_inat_def) - apply (simp add: slen_take_eq) - apply (cases "#s") - using i_rt_take_lemma1 [of n s] - apply (simp_all add: zero_inat_def) - done - -lemma i_rt_lemma_slen: "#s=Fin n ==> i_rt n s = UU" -by (simp add: i_rt_slen slen_take_lemma1) - -lemma stream_finite_i_rt [simp]: "stream_finite (i_rt n s) = stream_finite s" -apply (induct_tac n, auto) - apply (cases s, auto simp del: i_rt_Suc) -by (simp add: i_rt_Suc_back stream_finite_rt_eq)+ - -lemma take_i_rt_len_lemma: "ALL sl x j t. Fin sl = #x & n <= sl & - #(stream_take n$x) = Fin t & #(i_rt n x)= Fin j - --> Fin (j + t) = #x" -apply (induct n, auto) - apply (simp add: zero_inat_def) -apply (case_tac "x=UU",auto) - apply (simp add: zero_inat_def) -apply (drule stream_exhaust_eq [THEN iffD1],clarsimp) -apply (subgoal_tac "EX k. Fin k = #y",clarify) - apply (erule_tac x="k" in allE) - apply (erule_tac x="y" in allE,auto) - apply (erule_tac x="THE p. Suc p = t" in allE,auto) - apply (simp add: iSuc_def split: inat.splits) - apply (simp add: iSuc_def split: inat.splits) - apply (simp only: the_equality) - apply (simp add: iSuc_def split: inat.splits) - apply force -apply (simp add: iSuc_def split: inat.splits) -done - -lemma take_i_rt_len: -"[| Fin sl = #x; n <= sl; #(stream_take n$x) = Fin t; #(i_rt n x) = Fin j |] ==> - Fin (j + t) = #x" -by (blast intro: take_i_rt_len_lemma [rule_format]) - - -(* ----------------------------------------------------------------------- *) - section "i_th" -(* ----------------------------------------------------------------------- *) - -lemma i_th_i_rt_step: -"[| i_th n s1 << i_th n s2; i_rt (Suc n) s1 << i_rt (Suc n) s2 |] ==> - i_rt n s1 << i_rt n s2" -apply (simp add: i_th_def i_rt_Suc_back) -apply (cases "i_rt n s1", simp) -apply (cases "i_rt n s2", auto) -done - -lemma i_th_stream_take_Suc [rule_format]: - "ALL s. i_th n (stream_take (Suc n)$s) = i_th n s" -apply (induct_tac n,auto) - apply (simp add: i_th_def) - apply (case_tac "s=UU",auto) - apply (drule stream_exhaust_eq [THEN iffD1],auto) -apply (case_tac "s=UU",simp add: i_th_def) -apply (drule stream_exhaust_eq [THEN iffD1],auto) -by (simp add: i_th_def i_rt_Suc_forw) - -lemma i_th_last: "i_th n s && UU = i_rt n (stream_take (Suc n)$s)" -apply (insert surjectiv_scons [of "i_rt n (stream_take (Suc n)$s)"]) -apply (rule i_th_stream_take_Suc [THEN subst]) -apply (simp add: i_th_def i_rt_Suc_back [symmetric]) -by (simp add: i_rt_take_lemma1) - -lemma i_th_last_eq: -"i_th n s1 = i_th n s2 ==> i_rt n (stream_take (Suc n)$s1) = i_rt n (stream_take (Suc n)$s2)" -apply (insert i_th_last [of n s1]) -apply (insert i_th_last [of n s2]) -by auto - -lemma i_th_prefix_lemma: -"[| k <= n; stream_take (Suc n)$s1 << stream_take (Suc n)$s2 |] ==> - i_th k s1 << i_th k s2" -apply (insert i_th_stream_take_Suc [of k s1, THEN sym]) -apply (insert i_th_stream_take_Suc [of k s2, THEN sym],auto) -apply (simp add: i_th_def) -apply (rule monofun_cfun, auto) -apply (rule i_rt_mono) -by (blast intro: stream_take_lemma10) - -lemma take_i_rt_prefix_lemma1: - "stream_take (Suc n)$s1 << stream_take (Suc n)$s2 ==> - i_rt (Suc n) s1 << i_rt (Suc n) s2 ==> - i_rt n s1 << i_rt n s2 & stream_take n$s1 << stream_take n$s2" -apply auto - apply (insert i_th_prefix_lemma [of n n s1 s2]) - apply (rule i_th_i_rt_step,auto) -by (drule mono_stream_take_pred,simp) - -lemma take_i_rt_prefix_lemma: -"[| stream_take n$s1 << stream_take n$s2; i_rt n s1 << i_rt n s2 |] ==> s1 << s2" -apply (case_tac "n=0",simp) -apply (auto) -apply (subgoal_tac "stream_take 0$s1 << stream_take 0$s2 & - i_rt 0 s1 << i_rt 0 s2") - defer 1 - apply (rule zero_induct,blast) - apply (blast dest: take_i_rt_prefix_lemma1) -by simp - -lemma streams_prefix_lemma: "(s1 << s2) = - (stream_take n$s1 << stream_take n$s2 & i_rt n s1 << i_rt n s2)" -apply auto - apply (simp add: monofun_cfun_arg) - apply (simp add: i_rt_mono) -by (erule take_i_rt_prefix_lemma,simp) - -lemma streams_prefix_lemma1: - "[| stream_take n$s1 = stream_take n$s2; i_rt n s1 = i_rt n s2 |] ==> s1 = s2" -apply (simp add: po_eq_conv,auto) - apply (insert streams_prefix_lemma) - by blast+ - - -(* ----------------------------------------------------------------------- *) - section "sconc" -(* ----------------------------------------------------------------------- *) - -lemma UU_sconc [simp]: " UU ooo s = s " -by (simp add: sconc_def zero_inat_def) - -lemma scons_neq_UU: "a~=UU ==> a && s ~=UU" -by auto - -lemma singleton_sconc [rule_format, simp]: "x~=UU --> (x && UU) ooo y = x && y" -apply (simp add: sconc_def zero_inat_def iSuc_def split: inat.splits, auto) -apply (rule someI2_ex,auto) - apply (rule_tac x="x && y" in exI,auto) -apply (simp add: i_rt_Suc_forw) -apply (case_tac "xa=UU",simp) -by (drule stream_exhaust_eq [THEN iffD1],auto) - -lemma ex_sconc [rule_format]: - "ALL k y. #x = Fin k --> (EX w. stream_take k$w = x & i_rt k w = y)" -apply (case_tac "#x") - apply (rule stream_finite_ind [of x],auto) - apply (simp add: stream.finite_def) - apply (drule slen_take_lemma1,blast) - apply (simp_all add: zero_inat_def iSuc_def split: inat.splits) -apply (erule_tac x="y" in allE,auto) -by (rule_tac x="a && w" in exI,auto) - -lemma rt_sconc1: "Fin n = #x ==> i_rt n (x ooo y) = y" -apply (simp add: sconc_def split: inat.splits, arith?,auto) -apply (rule someI2_ex,auto) -by (drule ex_sconc,simp) - -lemma sconc_inj2: "\Fin n = #x; x ooo y = x ooo z\ \ y = z" -apply (frule_tac y=y in rt_sconc1) -by (auto elim: rt_sconc1) - -lemma sconc_UU [simp]:"s ooo UU = s" -apply (case_tac "#s") - apply (simp add: sconc_def) - apply (rule someI2_ex) - apply (rule_tac x="s" in exI) - apply auto - apply (drule slen_take_lemma1,auto) - apply (simp add: i_rt_lemma_slen) - apply (drule slen_take_lemma1,auto) - apply (simp add: i_rt_slen) -by (simp add: sconc_def) - -lemma stream_take_sconc [simp]: "Fin n = #x ==> stream_take n$(x ooo y) = x" -apply (simp add: sconc_def) -apply (cases "#x") -apply auto -apply (rule someI2_ex, auto) -by (drule ex_sconc,simp) - -lemma scons_sconc [rule_format,simp]: "a~=UU --> (a && x) ooo y = a && x ooo y" -apply (cases "#x",auto) - apply (simp add: sconc_def iSuc_Fin) - apply (rule someI2_ex) - apply (drule ex_sconc, simp) - apply (rule someI2_ex, auto) - apply (simp add: i_rt_Suc_forw) - apply (rule_tac x="a && x" in exI, auto) - apply (case_tac "xa=UU",auto) - apply (drule stream_exhaust_eq [THEN iffD1],auto) - apply (drule streams_prefix_lemma1,simp+) -by (simp add: sconc_def) - -lemma ft_sconc: "x ~= UU ==> ft$(x ooo y) = ft$x" -by (cases x, auto) - -lemma sconc_assoc: "(x ooo y) ooo z = x ooo y ooo z" -apply (case_tac "#x") - apply (rule stream_finite_ind [of x],auto simp del: scons_sconc) - apply (simp add: stream.finite_def del: scons_sconc) - apply (drule slen_take_lemma1,auto simp del: scons_sconc) - apply (case_tac "a = UU", auto) -by (simp add: sconc_def) - - -(* ----------------------------------------------------------------------- *) - -lemma cont_sconc_lemma1: "stream_finite x \ cont (\y. x ooo y)" -by (erule stream_finite_ind, simp_all) - -lemma cont_sconc_lemma2: "\ stream_finite x \ cont (\y. x ooo y)" -by (simp add: sconc_def slen_def) - -lemma cont_sconc: "cont (\y. x ooo y)" -apply (cases "stream_finite x") -apply (erule cont_sconc_lemma1) -apply (erule cont_sconc_lemma2) -done - -lemma sconc_mono: "y << y' ==> x ooo y << x ooo y'" -by (rule cont_sconc [THEN cont2mono, THEN monofunE]) - -lemma sconc_mono1 [simp]: "x << x ooo y" -by (rule sconc_mono [of UU, simplified]) - -(* ----------------------------------------------------------------------- *) - -lemma empty_sconc [simp]: "(x ooo y = UU) = (x = UU & y = UU)" -apply (case_tac "#x",auto) - apply (insert sconc_mono1 [of x y]) - by auto - -(* ----------------------------------------------------------------------- *) - -lemma rt_sconc [rule_format, simp]: "s~=UU --> rt$(s ooo x) = rt$s ooo x" -by (cases s, auto) - -lemma i_th_sconc_lemma [rule_format]: - "ALL x y. Fin n < #x --> i_th n (x ooo y) = i_th n x" -apply (induct_tac n, auto) -apply (simp add: Fin_0 i_th_def) -apply (simp add: slen_empty_eq ft_sconc) -apply (simp add: i_th_def) -apply (case_tac "x=UU",auto) -apply (drule stream_exhaust_eq [THEN iffD1], auto) -apply (erule_tac x="ya" in allE) -apply (case_tac "#ya") by simp_all - - - -(* ----------------------------------------------------------------------- *) - -lemma sconc_lemma [rule_format, simp]: "ALL s. stream_take n$s ooo i_rt n s = s" -apply (induct_tac n,auto) -apply (case_tac "s=UU",auto) -by (drule stream_exhaust_eq [THEN iffD1],auto) - -(* ----------------------------------------------------------------------- *) - subsection "pointwise equality" -(* ----------------------------------------------------------------------- *) - -lemma ex_last_stream_take_scons: "stream_take (Suc n)$s = - stream_take n$s ooo i_rt n (stream_take (Suc n)$s)" -by (insert sconc_lemma [of n "stream_take (Suc n)$s"],simp) - -lemma i_th_stream_take_eq: -"!!n. ALL n. i_th n s1 = i_th n s2 ==> stream_take n$s1 = stream_take n$s2" -apply (induct_tac n,auto) -apply (subgoal_tac "stream_take (Suc na)$s1 = - stream_take na$s1 ooo i_rt na (stream_take (Suc na)$s1)") - apply (subgoal_tac "i_rt na (stream_take (Suc na)$s1) = - i_rt na (stream_take (Suc na)$s2)") - apply (subgoal_tac "stream_take (Suc na)$s2 = - stream_take na$s2 ooo i_rt na (stream_take (Suc na)$s2)") - apply (insert ex_last_stream_take_scons,simp) - apply blast - apply (erule_tac x="na" in allE) - apply (insert i_th_last_eq [of _ s1 s2]) -by blast+ - -lemma pointwise_eq_lemma[rule_format]: "ALL n. i_th n s1 = i_th n s2 ==> s1 = s2" -by (insert i_th_stream_take_eq [THEN stream.take_lemma],blast) - -(* ----------------------------------------------------------------------- *) - subsection "finiteness" -(* ----------------------------------------------------------------------- *) - -lemma slen_sconc_finite1: - "[| #(x ooo y) = Infty; Fin n = #x |] ==> #y = Infty" -apply (case_tac "#y ~= Infty",auto) -apply (drule_tac y=y in rt_sconc1) -apply (insert stream_finite_i_rt [of n "x ooo y"]) -by (simp add: slen_infinite) - -lemma slen_sconc_infinite1: "#x=Infty ==> #(x ooo y) = Infty" -by (simp add: sconc_def) - -lemma slen_sconc_infinite2: "#y=Infty ==> #(x ooo y) = Infty" -apply (case_tac "#x") - apply (simp add: sconc_def) - apply (rule someI2_ex) - apply (drule ex_sconc,auto) - apply (erule contrapos_pp) - apply (insert stream_finite_i_rt) - apply (fastsimp simp add: slen_infinite,auto) -by (simp add: sconc_def) - -lemma sconc_finite: "(#x~=Infty & #y~=Infty) = (#(x ooo y)~=Infty)" -apply auto - apply (metis not_Infty_eq slen_sconc_finite1) - apply (metis not_Infty_eq slen_sconc_infinite1) -apply (metis not_Infty_eq slen_sconc_infinite2) -done - -(* ----------------------------------------------------------------------- *) - -lemma slen_sconc_mono3: "[| Fin n = #x; Fin k = #(x ooo y) |] ==> n <= k" -apply (insert slen_mono [of "x" "x ooo y"]) -apply (cases "#x") apply simp_all -apply (cases "#(x ooo y)") apply simp_all -done - -(* ----------------------------------------------------------------------- *) - subsection "finite slen" -(* ----------------------------------------------------------------------- *) - -lemma slen_sconc: "[| Fin n = #x; Fin m = #y |] ==> #(x ooo y) = Fin (n + m)" -apply (case_tac "#(x ooo y)") - apply (frule_tac y=y in rt_sconc1) - apply (insert take_i_rt_len [of "THE j. Fin j = #(x ooo y)" "x ooo y" n n m],simp) - apply (insert slen_sconc_mono3 [of n x _ y],simp) -by (insert sconc_finite [of x y],auto) - -(* ----------------------------------------------------------------------- *) - subsection "flat prefix" -(* ----------------------------------------------------------------------- *) - -lemma sconc_prefix: "(s1::'a::flat stream) << s2 ==> EX t. s1 ooo t = s2" -apply (case_tac "#s1") - apply (subgoal_tac "stream_take nat$s1 = stream_take nat$s2") - apply (rule_tac x="i_rt nat s2" in exI) - apply (simp add: sconc_def) - apply (rule someI2_ex) - apply (drule ex_sconc) - apply (simp,clarsimp,drule streams_prefix_lemma1) - apply (simp+,rule slen_take_lemma3 [of _ s1 s2]) - apply (simp+,rule_tac x="UU" in exI) -apply (insert slen_take_lemma3 [of _ s1 s2]) -by (rule stream.take_lemma,simp) - -(* ----------------------------------------------------------------------- *) - subsection "continuity" -(* ----------------------------------------------------------------------- *) - -lemma chain_sconc: "chain S ==> chain (%i. (x ooo S i))" -by (simp add: chain_def,auto simp add: sconc_mono) - -lemma chain_scons: "chain S ==> chain (%i. a && S i)" -apply (simp add: chain_def,auto) -by (rule monofun_cfun_arg,simp) - -lemma contlub_scons_lemma: "chain S ==> (LUB i. a && S i) = a && (LUB i. S i)" -by (rule cont2contlubE [OF cont_Rep_CFun2, symmetric]) - -lemma finite_lub_sconc: "chain Y ==> (stream_finite x) ==> - (LUB i. x ooo Y i) = (x ooo (LUB i. Y i))" -apply (rule stream_finite_ind [of x]) - apply (auto) -apply (subgoal_tac "(LUB i. a && (s ooo Y i)) = a && (LUB i. s ooo Y i)") - by (force,blast dest: contlub_scons_lemma chain_sconc) - -lemma contlub_sconc_lemma: - "chain Y ==> (LUB i. x ooo Y i) = (x ooo (LUB i. Y i))" -apply (case_tac "#x=Infty") - apply (simp add: sconc_def) -apply (drule finite_lub_sconc,auto simp add: slen_infinite) -done - -lemma monofun_sconc: "monofun (%y. x ooo y)" -by (simp add: monofun_def sconc_mono) - - -(* ----------------------------------------------------------------------- *) - section "constr_sconc" -(* ----------------------------------------------------------------------- *) - -lemma constr_sconc_UUs [simp]: "constr_sconc UU s = s" -by (simp add: constr_sconc_def zero_inat_def) - -lemma "x ooo y = constr_sconc x y" -apply (case_tac "#x") - apply (rule stream_finite_ind [of x],auto simp del: scons_sconc) - defer 1 - apply (simp add: constr_sconc_def del: scons_sconc) - apply (case_tac "#s") - apply (simp add: iSuc_Fin) - apply (case_tac "a=UU",auto simp del: scons_sconc) - apply (simp) - apply (simp add: sconc_def) - apply (simp add: constr_sconc_def) -apply (simp add: stream.finite_def) -by (drule slen_take_lemma1,auto) - -end