1 (* Title: HOL/SetInterval.thy
3 Author: Tobias Nipkow and Clemens Ballarin
4 Additions by Jeremy Avigad in March 2004
5 Copyright 2000 TU Muenchen
7 lessThan, greaterThan, atLeast, atMost and two-sided intervals
10 header {* Set intervals *}
17 lessThan :: "('a::ord) => 'a set" ("(1{..<_})")
20 atMost :: "('a::ord) => 'a set" ("(1{.._})")
23 greaterThan :: "('a::ord) => 'a set" ("(1{_<..})")
26 atLeast :: "('a::ord) => 'a set" ("(1{_..})")
29 greaterThanLessThan :: "['a::ord, 'a] => 'a set" ("(1{_<..<_})")
30 "{l<..<u} == {l<..} Int {..<u}"
32 atLeastLessThan :: "['a::ord, 'a] => 'a set" ("(1{_..<_})")
33 "{l..<u} == {l..} Int {..<u}"
35 greaterThanAtMost :: "['a::ord, 'a] => 'a set" ("(1{_<.._})")
36 "{l<..u} == {l<..} Int {..u}"
38 atLeastAtMost :: "['a::ord, 'a] => 'a set" ("(1{_.._})")
39 "{l..u} == {l..} Int {..u}"
41 text{* A note of warning when using @{term"{..<n}"} on type @{typ
42 nat}: it is equivalent to @{term"{0::nat..<n}"} but some lemmas involving
43 @{term"{m..<n}"} may not exist in @{term"{..<n}"}-form as well. *}
46 "@UNION_le" :: "nat => nat => 'b set => 'b set" ("(3UN _<=_./ _)" 10)
47 "@UNION_less" :: "nat => nat => 'b set => 'b set" ("(3UN _<_./ _)" 10)
48 "@INTER_le" :: "nat => nat => 'b set => 'b set" ("(3INT _<=_./ _)" 10)
49 "@INTER_less" :: "nat => nat => 'b set => 'b set" ("(3INT _<_./ _)" 10)
52 "@UNION_le" :: "nat => nat => 'b set => 'b set" ("(3\<Union> _\<le>_./ _)" 10)
53 "@UNION_less" :: "nat => nat => 'b set => 'b set" ("(3\<Union> _<_./ _)" 10)
54 "@INTER_le" :: "nat => nat => 'b set => 'b set" ("(3\<Inter> _\<le>_./ _)" 10)
55 "@INTER_less" :: "nat => nat => 'b set => 'b set" ("(3\<Inter> _<_./ _)" 10)
58 "@UNION_le" :: "nat \<Rightarrow> nat => 'b set => 'b set" ("(3\<Union>(00\<^bsub>_ \<le> _\<^esub>)/ _)" 10)
59 "@UNION_less" :: "nat \<Rightarrow> nat => 'b set => 'b set" ("(3\<Union>(00\<^bsub>_ < _\<^esub>)/ _)" 10)
60 "@INTER_le" :: "nat \<Rightarrow> nat => 'b set => 'b set" ("(3\<Inter>(00\<^bsub>_ \<le> _\<^esub>)/ _)" 10)
61 "@INTER_less" :: "nat \<Rightarrow> nat => 'b set => 'b set" ("(3\<Inter>(00\<^bsub>_ < _\<^esub>)/ _)" 10)
64 "UN i<=n. A" == "UN i:{..n}. A"
65 "UN i<n. A" == "UN i:{..<n}. A"
66 "INT i<=n. A" == "INT i:{..n}. A"
67 "INT i<n. A" == "INT i:{..<n}. A"
70 subsection {* Various equivalences *}
72 lemma lessThan_iff [iff]: "(i: lessThan k) = (i<k)"
73 by (simp add: lessThan_def)
75 lemma Compl_lessThan [simp]:
76 "!!k:: 'a::linorder. -lessThan k = atLeast k"
77 apply (auto simp add: lessThan_def atLeast_def)
80 lemma single_Diff_lessThan [simp]: "!!k:: 'a::order. {k} - lessThan k = {k}"
83 lemma greaterThan_iff [iff]: "(i: greaterThan k) = (k<i)"
84 by (simp add: greaterThan_def)
86 lemma Compl_greaterThan [simp]:
87 "!!k:: 'a::linorder. -greaterThan k = atMost k"
88 apply (simp add: greaterThan_def atMost_def le_def, auto)
91 lemma Compl_atMost [simp]: "!!k:: 'a::linorder. -atMost k = greaterThan k"
92 apply (subst Compl_greaterThan [symmetric])
93 apply (rule double_complement)
96 lemma atLeast_iff [iff]: "(i: atLeast k) = (k<=i)"
97 by (simp add: atLeast_def)
99 lemma Compl_atLeast [simp]:
100 "!!k:: 'a::linorder. -atLeast k = lessThan k"
101 apply (simp add: lessThan_def atLeast_def le_def, auto)
104 lemma atMost_iff [iff]: "(i: atMost k) = (i<=k)"
105 by (simp add: atMost_def)
107 lemma atMost_Int_atLeast: "!!n:: 'a::order. atMost n Int atLeast n = {n}"
108 by (blast intro: order_antisym)
111 subsection {* Logical Equivalences for Set Inclusion and Equality *}
113 lemma atLeast_subset_iff [iff]:
114 "(atLeast x \<subseteq> atLeast y) = (y \<le> (x::'a::order))"
115 by (blast intro: order_trans)
117 lemma atLeast_eq_iff [iff]:
118 "(atLeast x = atLeast y) = (x = (y::'a::linorder))"
119 by (blast intro: order_antisym order_trans)
121 lemma greaterThan_subset_iff [iff]:
122 "(greaterThan x \<subseteq> greaterThan y) = (y \<le> (x::'a::linorder))"
123 apply (auto simp add: greaterThan_def)
124 apply (subst linorder_not_less [symmetric], blast)
127 lemma greaterThan_eq_iff [iff]:
128 "(greaterThan x = greaterThan y) = (x = (y::'a::linorder))"
130 apply (erule equalityE)
131 apply (simp_all add: greaterThan_subset_iff)
134 lemma atMost_subset_iff [iff]: "(atMost x \<subseteq> atMost y) = (x \<le> (y::'a::order))"
135 by (blast intro: order_trans)
137 lemma atMost_eq_iff [iff]: "(atMost x = atMost y) = (x = (y::'a::linorder))"
138 by (blast intro: order_antisym order_trans)
140 lemma lessThan_subset_iff [iff]:
141 "(lessThan x \<subseteq> lessThan y) = (x \<le> (y::'a::linorder))"
142 apply (auto simp add: lessThan_def)
143 apply (subst linorder_not_less [symmetric], blast)
146 lemma lessThan_eq_iff [iff]:
147 "(lessThan x = lessThan y) = (x = (y::'a::linorder))"
149 apply (erule equalityE)
150 apply (simp_all add: lessThan_subset_iff)
154 subsection {*Two-sided intervals*}
156 lemma greaterThanLessThan_iff [simp,noatp]:
157 "(i : {l<..<u}) = (l < i & i < u)"
158 by (simp add: greaterThanLessThan_def)
160 lemma atLeastLessThan_iff [simp,noatp]:
161 "(i : {l..<u}) = (l <= i & i < u)"
162 by (simp add: atLeastLessThan_def)
164 lemma greaterThanAtMost_iff [simp,noatp]:
165 "(i : {l<..u}) = (l < i & i <= u)"
166 by (simp add: greaterThanAtMost_def)
168 lemma atLeastAtMost_iff [simp,noatp]:
169 "(i : {l..u}) = (l <= i & i <= u)"
170 by (simp add: atLeastAtMost_def)
172 text {* The above four lemmas could be declared as iffs.
173 If we do so, a call to blast in Hyperreal/Star.ML, lemma @{text STAR_Int}
174 seems to take forever (more than one hour). *}
176 subsubsection{* Emptyness and singletons *}
178 lemma atLeastAtMost_empty [simp]: "n < m ==> {m::'a::order..n} = {}";
179 by (auto simp add: atLeastAtMost_def atMost_def atLeast_def);
181 lemma atLeastLessThan_empty[simp]: "n \<le> m ==> {m..<n::'a::order} = {}"
182 by (auto simp add: atLeastLessThan_def)
184 lemma greaterThanAtMost_empty[simp]:"l \<le> k ==> {k<..(l::'a::order)} = {}"
185 by(auto simp:greaterThanAtMost_def greaterThan_def atMost_def)
187 lemma greaterThanLessThan_empty[simp]:"l \<le> k ==> {k<..(l::'a::order)} = {}"
188 by(auto simp:greaterThanLessThan_def greaterThan_def lessThan_def)
190 lemma atLeastAtMost_singleton [simp]: "{a::'a::order..a} = {a}";
191 by (auto simp add: atLeastAtMost_def atMost_def atLeast_def);
193 subsection {* Intervals of natural numbers *}
195 subsubsection {* The Constant @{term lessThan} *}
197 lemma lessThan_0 [simp]: "lessThan (0::nat) = {}"
198 by (simp add: lessThan_def)
200 lemma lessThan_Suc: "lessThan (Suc k) = insert k (lessThan k)"
201 by (simp add: lessThan_def less_Suc_eq, blast)
203 lemma lessThan_Suc_atMost: "lessThan (Suc k) = atMost k"
204 by (simp add: lessThan_def atMost_def less_Suc_eq_le)
206 lemma UN_lessThan_UNIV: "(UN m::nat. lessThan m) = UNIV"
209 subsubsection {* The Constant @{term greaterThan} *}
211 lemma greaterThan_0 [simp]: "greaterThan 0 = range Suc"
212 apply (simp add: greaterThan_def)
213 apply (blast dest: gr0_conv_Suc [THEN iffD1])
216 lemma greaterThan_Suc: "greaterThan (Suc k) = greaterThan k - {Suc k}"
217 apply (simp add: greaterThan_def)
218 apply (auto elim: linorder_neqE)
221 lemma INT_greaterThan_UNIV: "(INT m::nat. greaterThan m) = {}"
224 subsubsection {* The Constant @{term atLeast} *}
226 lemma atLeast_0 [simp]: "atLeast (0::nat) = UNIV"
227 by (unfold atLeast_def UNIV_def, simp)
229 lemma atLeast_Suc: "atLeast (Suc k) = atLeast k - {k}"
230 apply (simp add: atLeast_def)
231 apply (simp add: Suc_le_eq)
232 apply (simp add: order_le_less, blast)
235 lemma atLeast_Suc_greaterThan: "atLeast (Suc k) = greaterThan k"
236 by (auto simp add: greaterThan_def atLeast_def less_Suc_eq_le)
238 lemma UN_atLeast_UNIV: "(UN m::nat. atLeast m) = UNIV"
241 subsubsection {* The Constant @{term atMost} *}
243 lemma atMost_0 [simp]: "atMost (0::nat) = {0}"
244 by (simp add: atMost_def)
246 lemma atMost_Suc: "atMost (Suc k) = insert (Suc k) (atMost k)"
247 apply (simp add: atMost_def)
248 apply (simp add: less_Suc_eq order_le_less, blast)
251 lemma UN_atMost_UNIV: "(UN m::nat. atMost m) = UNIV"
254 subsubsection {* The Constant @{term atLeastLessThan} *}
256 text{*The orientation of the following rule is tricky. The lhs is
257 defined in terms of the rhs. Hence the chosen orientation makes sense
258 in this theory --- the reverse orientation complicates proofs (eg
259 nontermination). But outside, when the definition of the lhs is rarely
260 used, the opposite orientation seems preferable because it reduces a
261 specific concept to a more general one. *}
262 lemma atLeast0LessThan: "{0::nat..<n} = {..<n}"
263 by(simp add:lessThan_def atLeastLessThan_def)
265 declare atLeast0LessThan[symmetric, code unfold]
267 lemma atLeastLessThan0: "{m..<0::nat} = {}"
268 by (simp add: atLeastLessThan_def)
270 subsubsection {* Intervals of nats with @{term Suc} *}
272 text{*Not a simprule because the RHS is too messy.*}
273 lemma atLeastLessThanSuc:
274 "{m..<Suc n} = (if m \<le> n then insert n {m..<n} else {})"
275 by (auto simp add: atLeastLessThan_def)
277 lemma atLeastLessThan_singleton [simp]: "{m..<Suc m} = {m}"
278 by (auto simp add: atLeastLessThan_def)
280 lemma atLeast_sum_LessThan [simp]: "{m + k..<k::nat} = {}"
281 by (induct k, simp_all add: atLeastLessThanSuc)
283 lemma atLeastSucLessThan [simp]: "{Suc n..<n} = {}"
284 by (auto simp add: atLeastLessThan_def)
286 lemma atLeastLessThanSuc_atLeastAtMost: "{l..<Suc u} = {l..u}"
287 by (simp add: lessThan_Suc_atMost atLeastAtMost_def atLeastLessThan_def)
289 lemma atLeastSucAtMost_greaterThanAtMost: "{Suc l..u} = {l<..u}"
290 by (simp add: atLeast_Suc_greaterThan atLeastAtMost_def
291 greaterThanAtMost_def)
293 lemma atLeastSucLessThan_greaterThanLessThan: "{Suc l..<u} = {l<..<u}"
294 by (simp add: atLeast_Suc_greaterThan atLeastLessThan_def
295 greaterThanLessThan_def)
297 lemma atLeastAtMostSuc_conv: "m \<le> Suc n \<Longrightarrow> {m..Suc n} = insert (Suc n) {m..n}"
298 by (auto simp add: atLeastAtMost_def)
300 subsubsection {* Image *}
302 lemma image_add_atLeastAtMost:
303 "(%n::nat. n+k) ` {i..j} = {i+k..j+k}" (is "?A = ?B")
305 show "?A \<subseteq> ?B" by auto
307 show "?B \<subseteq> ?A"
309 fix n assume a: "n : ?B"
310 hence "n - k : {i..j}" by auto
311 moreover have "n = (n - k) + k" using a by auto
312 ultimately show "n : ?A" by blast
316 lemma image_add_atLeastLessThan:
317 "(%n::nat. n+k) ` {i..<j} = {i+k..<j+k}" (is "?A = ?B")
319 show "?A \<subseteq> ?B" by auto
321 show "?B \<subseteq> ?A"
323 fix n assume a: "n : ?B"
324 hence "n - k : {i..<j}" by auto
325 moreover have "n = (n - k) + k" using a by auto
326 ultimately show "n : ?A" by blast
330 corollary image_Suc_atLeastAtMost[simp]:
331 "Suc ` {i..j} = {Suc i..Suc j}"
332 using image_add_atLeastAtMost[where k=1] by simp
334 corollary image_Suc_atLeastLessThan[simp]:
335 "Suc ` {i..<j} = {Suc i..<Suc j}"
336 using image_add_atLeastLessThan[where k=1] by simp
338 lemma image_add_int_atLeastLessThan:
339 "(%x. x + (l::int)) ` {0..<u-l} = {l..<u}"
340 apply (auto simp add: image_def)
341 apply (rule_tac x = "x - l" in bexI)
346 subsubsection {* Finiteness *}
348 lemma finite_lessThan [iff]: fixes k :: nat shows "finite {..<k}"
349 by (induct k) (simp_all add: lessThan_Suc)
351 lemma finite_atMost [iff]: fixes k :: nat shows "finite {..k}"
352 by (induct k) (simp_all add: atMost_Suc)
354 lemma finite_greaterThanLessThan [iff]:
355 fixes l :: nat shows "finite {l<..<u}"
356 by (simp add: greaterThanLessThan_def)
358 lemma finite_atLeastLessThan [iff]:
359 fixes l :: nat shows "finite {l..<u}"
360 by (simp add: atLeastLessThan_def)
362 lemma finite_greaterThanAtMost [iff]:
363 fixes l :: nat shows "finite {l<..u}"
364 by (simp add: greaterThanAtMost_def)
366 lemma finite_atLeastAtMost [iff]:
367 fixes l :: nat shows "finite {l..u}"
368 by (simp add: atLeastAtMost_def)
370 lemma bounded_nat_set_is_finite:
371 "(ALL i:N. i < (n::nat)) ==> finite N"
372 -- {* A bounded set of natural numbers is finite. *}
373 apply (rule finite_subset)
374 apply (rule_tac [2] finite_lessThan, auto)
377 subsubsection {* Cardinality *}
379 lemma card_lessThan [simp]: "card {..<u} = u"
380 by (induct u, simp_all add: lessThan_Suc)
382 lemma card_atMost [simp]: "card {..u} = Suc u"
383 by (simp add: lessThan_Suc_atMost [THEN sym])
385 lemma card_atLeastLessThan [simp]: "card {l..<u} = u - l"
386 apply (subgoal_tac "card {l..<u} = card {..<u-l}")
387 apply (erule ssubst, rule card_lessThan)
388 apply (subgoal_tac "(%x. x + l) ` {..<u-l} = {l..<u}")
390 apply (rule card_image)
391 apply (simp add: inj_on_def)
392 apply (auto simp add: image_def atLeastLessThan_def lessThan_def)
393 apply (rule_tac x = "x - l" in exI)
397 lemma card_atLeastAtMost [simp]: "card {l..u} = Suc u - l"
398 by (subst atLeastLessThanSuc_atLeastAtMost [THEN sym], simp)
400 lemma card_greaterThanAtMost [simp]: "card {l<..u} = u - l"
401 by (subst atLeastSucAtMost_greaterThanAtMost [THEN sym], simp)
403 lemma card_greaterThanLessThan [simp]: "card {l<..<u} = u - Suc l"
404 by (subst atLeastSucLessThan_greaterThanLessThan [THEN sym], simp)
406 subsection {* Intervals of integers *}
408 lemma atLeastLessThanPlusOne_atLeastAtMost_int: "{l..<u+1} = {l..(u::int)}"
409 by (auto simp add: atLeastAtMost_def atLeastLessThan_def)
411 lemma atLeastPlusOneAtMost_greaterThanAtMost_int: "{l+1..u} = {l<..(u::int)}"
412 by (auto simp add: atLeastAtMost_def greaterThanAtMost_def)
414 lemma atLeastPlusOneLessThan_greaterThanLessThan_int:
415 "{l+1..<u} = {l<..<u::int}"
416 by (auto simp add: atLeastLessThan_def greaterThanLessThan_def)
418 subsubsection {* Finiteness *}
420 lemma image_atLeastZeroLessThan_int: "0 \<le> u ==>
421 {(0::int)..<u} = int ` {..<nat u}"
422 apply (unfold image_def lessThan_def)
424 apply (rule_tac x = "nat x" in exI)
425 apply (auto simp add: zless_nat_conj zless_nat_eq_int_zless [THEN sym])
428 lemma finite_atLeastZeroLessThan_int: "finite {(0::int)..<u}"
429 apply (case_tac "0 \<le> u")
430 apply (subst image_atLeastZeroLessThan_int, assumption)
431 apply (rule finite_imageI)
435 lemma finite_atLeastLessThan_int [iff]: "finite {l..<u::int}"
436 apply (subgoal_tac "(%x. x + l) ` {0..<u-l} = {l..<u}")
438 apply (rule finite_imageI)
439 apply (rule finite_atLeastZeroLessThan_int)
440 apply (rule image_add_int_atLeastLessThan)
443 lemma finite_atLeastAtMost_int [iff]: "finite {l..(u::int)}"
444 by (subst atLeastLessThanPlusOne_atLeastAtMost_int [THEN sym], simp)
446 lemma finite_greaterThanAtMost_int [iff]: "finite {l<..(u::int)}"
447 by (subst atLeastPlusOneAtMost_greaterThanAtMost_int [THEN sym], simp)
449 lemma finite_greaterThanLessThan_int [iff]: "finite {l<..<u::int}"
450 by (subst atLeastPlusOneLessThan_greaterThanLessThan_int [THEN sym], simp)
452 subsubsection {* Cardinality *}
454 lemma card_atLeastZeroLessThan_int: "card {(0::int)..<u} = nat u"
455 apply (case_tac "0 \<le> u")
456 apply (subst image_atLeastZeroLessThan_int, assumption)
457 apply (subst card_image)
458 apply (auto simp add: inj_on_def)
461 lemma card_atLeastLessThan_int [simp]: "card {l..<u} = nat (u - l)"
462 apply (subgoal_tac "card {l..<u} = card {0..<u-l}")
463 apply (erule ssubst, rule card_atLeastZeroLessThan_int)
464 apply (subgoal_tac "(%x. x + l) ` {0..<u-l} = {l..<u}")
466 apply (rule card_image)
467 apply (simp add: inj_on_def)
468 apply (rule image_add_int_atLeastLessThan)
471 lemma card_atLeastAtMost_int [simp]: "card {l..u} = nat (u - l + 1)"
472 apply (subst atLeastLessThanPlusOne_atLeastAtMost_int [THEN sym])
473 apply (auto simp add: compare_rls)
476 lemma card_greaterThanAtMost_int [simp]: "card {l<..u} = nat (u - l)"
477 by (subst atLeastPlusOneAtMost_greaterThanAtMost_int [THEN sym], simp)
479 lemma card_greaterThanLessThan_int [simp]: "card {l<..<u} = nat (u - (l + 1))"
480 by (subst atLeastPlusOneLessThan_greaterThanLessThan_int [THEN sym], simp)
483 subsection {*Lemmas useful with the summation operator setsum*}
485 text {* For examples, see Algebra/poly/UnivPoly2.thy *}
487 subsubsection {* Disjoint Unions *}
489 text {* Singletons and open intervals *}
491 lemma ivl_disj_un_singleton:
492 "{l::'a::linorder} Un {l<..} = {l..}"
493 "{..<u} Un {u::'a::linorder} = {..u}"
494 "(l::'a::linorder) < u ==> {l} Un {l<..<u} = {l..<u}"
495 "(l::'a::linorder) < u ==> {l<..<u} Un {u} = {l<..u}"
496 "(l::'a::linorder) <= u ==> {l} Un {l<..u} = {l..u}"
497 "(l::'a::linorder) <= u ==> {l..<u} Un {u} = {l..u}"
500 text {* One- and two-sided intervals *}
502 lemma ivl_disj_un_one:
503 "(l::'a::linorder) < u ==> {..l} Un {l<..<u} = {..<u}"
504 "(l::'a::linorder) <= u ==> {..<l} Un {l..<u} = {..<u}"
505 "(l::'a::linorder) <= u ==> {..l} Un {l<..u} = {..u}"
506 "(l::'a::linorder) <= u ==> {..<l} Un {l..u} = {..u}"
507 "(l::'a::linorder) <= u ==> {l<..u} Un {u<..} = {l<..}"
508 "(l::'a::linorder) < u ==> {l<..<u} Un {u..} = {l<..}"
509 "(l::'a::linorder) <= u ==> {l..u} Un {u<..} = {l..}"
510 "(l::'a::linorder) <= u ==> {l..<u} Un {u..} = {l..}"
513 text {* Two- and two-sided intervals *}
515 lemma ivl_disj_un_two:
516 "[| (l::'a::linorder) < m; m <= u |] ==> {l<..<m} Un {m..<u} = {l<..<u}"
517 "[| (l::'a::linorder) <= m; m < u |] ==> {l<..m} Un {m<..<u} = {l<..<u}"
518 "[| (l::'a::linorder) <= m; m <= u |] ==> {l..<m} Un {m..<u} = {l..<u}"
519 "[| (l::'a::linorder) <= m; m < u |] ==> {l..m} Un {m<..<u} = {l..<u}"
520 "[| (l::'a::linorder) < m; m <= u |] ==> {l<..<m} Un {m..u} = {l<..u}"
521 "[| (l::'a::linorder) <= m; m <= u |] ==> {l<..m} Un {m<..u} = {l<..u}"
522 "[| (l::'a::linorder) <= m; m <= u |] ==> {l..<m} Un {m..u} = {l..u}"
523 "[| (l::'a::linorder) <= m; m <= u |] ==> {l..m} Un {m<..u} = {l..u}"
526 lemmas ivl_disj_un = ivl_disj_un_singleton ivl_disj_un_one ivl_disj_un_two
528 subsubsection {* Disjoint Intersections *}
530 text {* Singletons and open intervals *}
532 lemma ivl_disj_int_singleton:
533 "{l::'a::order} Int {l<..} = {}"
534 "{..<u} Int {u} = {}"
535 "{l} Int {l<..<u} = {}"
536 "{l<..<u} Int {u} = {}"
537 "{l} Int {l<..u} = {}"
538 "{l..<u} Int {u} = {}"
541 text {* One- and two-sided intervals *}
543 lemma ivl_disj_int_one:
544 "{..l::'a::order} Int {l<..<u} = {}"
545 "{..<l} Int {l..<u} = {}"
546 "{..l} Int {l<..u} = {}"
547 "{..<l} Int {l..u} = {}"
548 "{l<..u} Int {u<..} = {}"
549 "{l<..<u} Int {u..} = {}"
550 "{l..u} Int {u<..} = {}"
551 "{l..<u} Int {u..} = {}"
554 text {* Two- and two-sided intervals *}
556 lemma ivl_disj_int_two:
557 "{l::'a::order<..<m} Int {m..<u} = {}"
558 "{l<..m} Int {m<..<u} = {}"
559 "{l..<m} Int {m..<u} = {}"
560 "{l..m} Int {m<..<u} = {}"
561 "{l<..<m} Int {m..u} = {}"
562 "{l<..m} Int {m<..u} = {}"
563 "{l..<m} Int {m..u} = {}"
564 "{l..m} Int {m<..u} = {}"
567 lemmas ivl_disj_int = ivl_disj_int_singleton ivl_disj_int_one ivl_disj_int_two
569 subsubsection {* Some Differences *}
571 lemma ivl_diff[simp]:
572 "i \<le> n \<Longrightarrow> {i..<m} - {i..<n} = {n..<(m::'a::linorder)}"
576 subsubsection {* Some Subset Conditions *}
578 lemma ivl_subset [simp,noatp]:
579 "({i..<j} \<subseteq> {m..<n}) = (j \<le> i | m \<le> i & j \<le> (n::'a::linorder))"
580 apply(auto simp:linorder_not_le)
582 apply(insert linorder_le_less_linear[of i n])
583 apply(clarsimp simp:linorder_not_le)
588 subsection {* Summation indexed over intervals *}
591 "_from_to_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(SUM _ = _.._./ _)" [0,0,0,10] 10)
592 "_from_upto_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(SUM _ = _..<_./ _)" [0,0,0,10] 10)
593 "_upt_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(SUM _<_./ _)" [0,0,10] 10)
594 "_upto_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(SUM _<=_./ _)" [0,0,10] 10)
596 "_from_to_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Sum>_ = _.._./ _)" [0,0,0,10] 10)
597 "_from_upto_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Sum>_ = _..<_./ _)" [0,0,0,10] 10)
598 "_upt_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Sum>_<_./ _)" [0,0,10] 10)
599 "_upto_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Sum>_\<le>_./ _)" [0,0,10] 10)
601 "_from_to_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Sum>_ = _.._./ _)" [0,0,0,10] 10)
602 "_from_upto_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Sum>_ = _..<_./ _)" [0,0,0,10] 10)
603 "_upt_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Sum>_<_./ _)" [0,0,10] 10)
604 "_upto_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b" ("(3\<Sum>_\<le>_./ _)" [0,0,10] 10)
605 syntax (latex_sum output)
606 "_from_to_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b"
607 ("(3\<^raw:$\sum_{>_ = _\<^raw:}^{>_\<^raw:}$> _)" [0,0,0,10] 10)
608 "_from_upto_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b"
609 ("(3\<^raw:$\sum_{>_ = _\<^raw:}^{<>_\<^raw:}$> _)" [0,0,0,10] 10)
610 "_upt_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b"
611 ("(3\<^raw:$\sum_{>_ < _\<^raw:}$> _)" [0,0,10] 10)
612 "_upto_setsum" :: "idt \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> 'b"
613 ("(3\<^raw:$\sum_{>_ \<le> _\<^raw:}$> _)" [0,0,10] 10)
616 "\<Sum>x=a..b. t" == "setsum (%x. t) {a..b}"
617 "\<Sum>x=a..<b. t" == "setsum (%x. t) {a..<b}"
618 "\<Sum>i\<le>n. t" == "setsum (\<lambda>i. t) {..n}"
619 "\<Sum>i<n. t" == "setsum (\<lambda>i. t) {..<n}"
621 text{* The above introduces some pretty alternative syntaxes for
622 summation over intervals:
626 @{term[source]"\<Sum>x\<in>{a..b}. e"} & @{term"\<Sum>x=a..b. e"} & @{term[mode=latex_sum]"\<Sum>x=a..b. e"}\\
627 @{term[source]"\<Sum>x\<in>{a..<b}. e"} & @{term"\<Sum>x=a..<b. e"} & @{term[mode=latex_sum]"\<Sum>x=a..<b. e"}\\
628 @{term[source]"\<Sum>x\<in>{..b}. e"} & @{term"\<Sum>x\<le>b. e"} & @{term[mode=latex_sum]"\<Sum>x\<le>b. e"}\\
629 @{term[source]"\<Sum>x\<in>{..<b}. e"} & @{term"\<Sum>x<b. e"} & @{term[mode=latex_sum]"\<Sum>x<b. e"}
632 The left column shows the term before introduction of the new syntax,
633 the middle column shows the new (default) syntax, and the right column
634 shows a special syntax. The latter is only meaningful for latex output
635 and has to be activated explicitly by setting the print mode to
636 @{text latex_sum} (e.g.\ via @{text "mode = latex_sum"} in
637 antiquotations). It is not the default \LaTeX\ output because it only
638 works well with italic-style formulae, not tt-style.
640 Note that for uniformity on @{typ nat} it is better to use
641 @{term"\<Sum>x::nat=0..<n. e"} rather than @{text"\<Sum>x<n. e"}: @{text setsum} may
642 not provide all lemmas available for @{term"{m..<n}"} also in the
643 special form for @{term"{..<n}"}. *}
645 text{* This congruence rule should be used for sums over intervals as
646 the standard theorem @{text[source]setsum_cong} does not work well
647 with the simplifier who adds the unsimplified premise @{term"x:B"} to
650 lemma setsum_ivl_cong:
651 "\<lbrakk>a = c; b = d; !!x. \<lbrakk> c \<le> x; x < d \<rbrakk> \<Longrightarrow> f x = g x \<rbrakk> \<Longrightarrow>
652 setsum f {a..<b} = setsum g {c..<d}"
653 by(rule setsum_cong, simp_all)
655 (* FIXME why are the following simp rules but the corresponding eqns
656 on intervals are not? *)
658 lemma setsum_atMost_Suc[simp]: "(\<Sum>i \<le> Suc n. f i) = (\<Sum>i \<le> n. f i) + f(Suc n)"
659 by (simp add:atMost_Suc add_ac)
661 lemma setsum_lessThan_Suc[simp]: "(\<Sum>i < Suc n. f i) = (\<Sum>i < n. f i) + f n"
662 by (simp add:lessThan_Suc add_ac)
664 lemma setsum_cl_ivl_Suc[simp]:
665 "setsum f {m..Suc n} = (if Suc n < m then 0 else setsum f {m..n} + f(Suc n))"
666 by (auto simp:add_ac atLeastAtMostSuc_conv)
668 lemma setsum_op_ivl_Suc[simp]:
669 "setsum f {m..<Suc n} = (if n < m then 0 else setsum f {m..<n} + f(n))"
670 by (auto simp:add_ac atLeastLessThanSuc)
672 lemma setsum_cl_ivl_add_one_nat: "(n::nat) <= m + 1 ==>
673 (\<Sum>i=n..m+1. f i) = (\<Sum>i=n..m. f i) + f(m + 1)"
674 by (auto simp:add_ac atLeastAtMostSuc_conv)
676 lemma setsum_add_nat_ivl: "\<lbrakk> m \<le> n; n \<le> p \<rbrakk> \<Longrightarrow>
677 setsum f {m..<n} + setsum f {n..<p} = setsum f {m..<p::nat}"
678 by (simp add:setsum_Un_disjoint[symmetric] ivl_disj_int ivl_disj_un)
680 lemma setsum_diff_nat_ivl:
681 fixes f :: "nat \<Rightarrow> 'a::ab_group_add"
682 shows "\<lbrakk> m \<le> n; n \<le> p \<rbrakk> \<Longrightarrow>
683 setsum f {m..<p} - setsum f {m..<n} = setsum f {n..<p}"
684 using setsum_add_nat_ivl [of m n p f,symmetric]
685 apply (simp add: add_ac)
688 subsection{* Shifting bounds *}
690 lemma setsum_shift_bounds_nat_ivl:
691 "setsum f {m+k..<n+k} = setsum (%i. f(i + k)){m..<n::nat}"
692 by (induct "n", auto simp:atLeastLessThanSuc)
694 lemma setsum_shift_bounds_cl_nat_ivl:
695 "setsum f {m+k..n+k} = setsum (%i. f(i + k)){m..n::nat}"
696 apply (insert setsum_reindex[OF inj_on_add_nat, where h=f and B = "{m..n}"])
697 apply (simp add:image_add_atLeastAtMost o_def)
700 corollary setsum_shift_bounds_cl_Suc_ivl:
701 "setsum f {Suc m..Suc n} = setsum (%i. f(Suc i)){m..n}"
702 by (simp add:setsum_shift_bounds_cl_nat_ivl[where k=1,simplified])
704 corollary setsum_shift_bounds_Suc_ivl:
705 "setsum f {Suc m..<Suc n} = setsum (%i. f(Suc i)){m..<n}"
706 by (simp add:setsum_shift_bounds_nat_ivl[where k=1,simplified])
711 shows "(\<Sum>x\<in>{m..n}. P x) = P m + (\<Sum>x\<in>{m<..n}. P x)" (is "?lhs = ?rhs")
714 have "{m..n} = {m} \<union> {m<..n}"
715 by (auto intro: ivl_disj_un_singleton)
716 hence "?lhs = (\<Sum>x\<in>{m} \<union> {m<..n}. P x)"
717 by (simp add: atLeast0LessThan)
718 also have "\<dots> = ?rhs" by simp
719 finally show ?thesis .
722 lemma setsum_head_upt:
725 shows "(\<Sum>x<m. P x) = P 0 + (\<Sum>x\<in>{1..<m}. P x)"
727 have "(\<Sum>x<m. P x) = (\<Sum>x\<in>{0..<m}. P x)"
728 by (simp add: atLeast0LessThan)
731 have "\<dots> = (\<Sum>x\<in>{0..m - 1}. P x)"
732 by (cases m) (auto simp add: atLeastLessThanSuc_atLeastAtMost)
734 have "\<dots> = P 0 + (\<Sum>x\<in>{0<..m - 1}. P x)"
735 by (simp add: setsum_head)
738 have "{0<..m - 1} = {1..<m}"
739 by (cases m) (auto simp add: atLeastLessThanSuc_atLeastAtMost)
740 finally show ?thesis .
743 subsection {* The formula for geometric sums *}
746 "x ~= 1 ==> (\<Sum>i=0..<n. x ^ i) =
747 (x ^ n - 1) / (x - 1::'a::{field, recpower})"
748 by (induct "n") (simp_all add:field_simps power_Suc)
750 subsection {* The formula for arithmetic sums *}
753 "((1::'a::comm_semiring_1) + 1)*(\<Sum>i\<in>{1..n}. of_nat i) =
754 of_nat n*((of_nat n)+1)"
760 then show ?case by (simp add: ring_simps)
763 theorem arith_series_general:
764 "((1::'a::comm_semiring_1) + 1) * (\<Sum>i\<in>{..<n}. a + of_nat i * d) =
765 of_nat n * (a + (a + of_nat(n - 1)*d))"
768 let ?I = "\<lambda>i. of_nat i" and ?n = "of_nat n"
770 "(\<Sum>i\<in>{..<n}. a+?I i*d) =
771 ((\<Sum>i\<in>{..<n}. a) + (\<Sum>i\<in>{..<n}. ?I i*d))"
772 by (rule setsum_addf)
773 also from ngt1 have "\<dots> = ?n*a + (\<Sum>i\<in>{..<n}. ?I i*d)" by simp
774 also from ngt1 have "\<dots> = (?n*a + d*(\<Sum>i\<in>{1..<n}. ?I i))"
775 by (simp add: setsum_right_distrib setsum_head_upt mult_ac)
776 also have "(1+1)*\<dots> = (1+1)*?n*a + d*(1+1)*(\<Sum>i\<in>{1..<n}. ?I i)"
777 by (simp add: left_distrib right_distrib)
778 also from ngt1 have "{1..<n} = {1..n - 1}"
779 by (cases n) (auto simp: atLeastLessThanSuc_atLeastAtMost)
781 have "(1+1)*?n*a + d*(1+1)*(\<Sum>i\<in>{1..n - 1}. ?I i) = ((1+1)*?n*a + d*?I (n - 1)*?I n)"
782 by (simp only: mult_ac gauss_sum [of "n - 1"])
783 (simp add: mult_ac trans [OF add_commute of_nat_Suc [symmetric]])
784 finally show ?thesis by (simp add: mult_ac add_ac right_distrib)
786 assume "\<not>(n > 1)"
787 hence "n = 1 \<or> n = 0" by auto
788 thus ?thesis by (auto simp: mult_ac right_distrib)
791 lemma arith_series_nat:
792 "Suc (Suc 0) * (\<Sum>i\<in>{..<n}. a+i*d) = n * (a + (a+(n - 1)*d))"
795 "((1::nat) + 1) * (\<Sum>i\<in>{..<n::nat}. a + of_nat(i)*d) =
796 of_nat(n) * (a + (a + of_nat(n - 1)*d))"
797 by (rule arith_series_general)
798 thus ?thesis by (auto simp add: of_nat_id)
801 lemma arith_series_int:
802 "(2::int) * (\<Sum>i\<in>{..<n}. a + of_nat i * d) =
803 of_nat n * (a + (a + of_nat(n - 1)*d))"
806 "((1::int) + 1) * (\<Sum>i\<in>{..<n}. a + of_nat i * d) =
807 of_nat(n) * (a + (a + of_nat(n - 1)*d))"
808 by (rule arith_series_general)
812 lemma sum_diff_distrib:
813 fixes P::"nat\<Rightarrow>nat"
815 "\<forall>x. Q x \<le> P x \<Longrightarrow>
816 (\<Sum>x<n. P x) - (\<Sum>x<n. Q x) = (\<Sum>x<n. P x - Q x)"
818 case 0 show ?case by simp
822 let ?lhs = "(\<Sum>x<n. P x) - (\<Sum>x<n. Q x)"
823 let ?rhs = "\<Sum>x<n. P x - Q x"
825 from Suc have "?lhs = ?rhs" by simp
827 from Suc have "?lhs + P n - Q n = ?rhs + (P n - Q n)" by simp
830 "(\<Sum>x<n. P x) + P n - ((\<Sum>x<n. Q x) + Q n) = ?rhs + (P n - Q n)"
831 by (subst diff_diff_left[symmetric],
832 subst diff_add_assoc2)
833 (auto simp: diff_add_assoc2 intro: setsum_mono)
841 val Compl_atLeast = thm "Compl_atLeast";
842 val Compl_atMost = thm "Compl_atMost";
843 val Compl_greaterThan = thm "Compl_greaterThan";
844 val Compl_lessThan = thm "Compl_lessThan";
845 val INT_greaterThan_UNIV = thm "INT_greaterThan_UNIV";
846 val UN_atLeast_UNIV = thm "UN_atLeast_UNIV";
847 val UN_atMost_UNIV = thm "UN_atMost_UNIV";
848 val UN_lessThan_UNIV = thm "UN_lessThan_UNIV";
849 val atLeastAtMost_def = thm "atLeastAtMost_def";
850 val atLeastAtMost_iff = thm "atLeastAtMost_iff";
851 val atLeastLessThan_def = thm "atLeastLessThan_def";
852 val atLeastLessThan_iff = thm "atLeastLessThan_iff";
853 val atLeast_0 = thm "atLeast_0";
854 val atLeast_Suc = thm "atLeast_Suc";
855 val atLeast_def = thm "atLeast_def";
856 val atLeast_iff = thm "atLeast_iff";
857 val atMost_0 = thm "atMost_0";
858 val atMost_Int_atLeast = thm "atMost_Int_atLeast";
859 val atMost_Suc = thm "atMost_Suc";
860 val atMost_def = thm "atMost_def";
861 val atMost_iff = thm "atMost_iff";
862 val greaterThanAtMost_def = thm "greaterThanAtMost_def";
863 val greaterThanAtMost_iff = thm "greaterThanAtMost_iff";
864 val greaterThanLessThan_def = thm "greaterThanLessThan_def";
865 val greaterThanLessThan_iff = thm "greaterThanLessThan_iff";
866 val greaterThan_0 = thm "greaterThan_0";
867 val greaterThan_Suc = thm "greaterThan_Suc";
868 val greaterThan_def = thm "greaterThan_def";
869 val greaterThan_iff = thm "greaterThan_iff";
870 val ivl_disj_int = thms "ivl_disj_int";
871 val ivl_disj_int_one = thms "ivl_disj_int_one";
872 val ivl_disj_int_singleton = thms "ivl_disj_int_singleton";
873 val ivl_disj_int_two = thms "ivl_disj_int_two";
874 val ivl_disj_un = thms "ivl_disj_un";
875 val ivl_disj_un_one = thms "ivl_disj_un_one";
876 val ivl_disj_un_singleton = thms "ivl_disj_un_singleton";
877 val ivl_disj_un_two = thms "ivl_disj_un_two";
878 val lessThan_0 = thm "lessThan_0";
879 val lessThan_Suc = thm "lessThan_Suc";
880 val lessThan_Suc_atMost = thm "lessThan_Suc_atMost";
881 val lessThan_def = thm "lessThan_def";
882 val lessThan_iff = thm "lessThan_iff";
883 val single_Diff_lessThan = thm "single_Diff_lessThan";
885 val bounded_nat_set_is_finite = thm "bounded_nat_set_is_finite";
886 val finite_atMost = thm "finite_atMost";
887 val finite_lessThan = thm "finite_lessThan";