--- a/src/HOL/Hyperreal/MacLaurin.thy Tue May 11 14:00:02 2004 +0200
+++ b/src/HOL/Hyperreal/MacLaurin.thy Tue May 11 20:11:08 2004 +0200
@@ -4,4 +4,46 @@
Description : MacLaurin series
*)
-MacLaurin = Log
+theory MacLaurin = Log
+files ("MacLaurin_lemmas.ML"):
+
+use "MacLaurin_lemmas.ML"
+
+lemma Maclaurin_sin_bound:
+ "abs(sin x - sumr 0 n (%m. (if even m then 0 else ((- 1) ^ ((m - (Suc 0)) div 2)) / real (fact m)) *
+ x ^ m)) <= inverse(real (fact n)) * abs(x) ^ n"
+proof -
+ have "!! x (y::real). x <= 1 \<Longrightarrow> 0 <= y \<Longrightarrow> x * y \<le> 1 * y"
+ by (rule_tac mult_right_mono,simp_all)
+ note est = this[simplified]
+ show ?thesis
+ apply (cut_tac f=sin and n=n and x=x and
+ diff = "%n x. if n mod 4 = 0 then sin(x) else if n mod 4 = 1 then cos(x) else if n mod 4 = 2 then -sin(x) else -cos(x)"
+ in Maclaurin_all_le_objl)
+ apply (tactic{* (Step_tac 1) *})
+ apply (simp)
+ apply (subst mod_Suc_eq_Suc_mod)
+ apply (tactic{* cut_inst_tac [("m1","m")] (CLAIM "0 < (4::nat)" RS mod_less_divisor RS lemma_exhaust_less_4) 1*})
+ apply (tactic{* Step_tac 1 *})
+ apply (simp)+
+ apply (rule DERIV_minus, simp+)
+ apply (rule lemma_DERIV_subst, rule DERIV_minus, rule DERIV_cos, simp)
+ apply (tactic{* dtac ssubst 1 THEN assume_tac 2 *})
+ apply (tactic {* rtac (ARITH_PROVE "[|x = y; abs u <= (v::real) |] ==> abs ((x + u) - y) <= v") 1 *})
+ apply (rule sumr_fun_eq)
+ apply (tactic{* Step_tac 1 *})
+ apply (tactic{*rtac (CLAIM "x = y ==> x * z = y * (z::real)") 1*})
+ apply (subst even_even_mod_4_iff)
+ apply (tactic{* cut_inst_tac [("m1","r")] (CLAIM "0 < (4::nat)" RS mod_less_divisor RS lemma_exhaust_less_4) 1 *})
+ apply (tactic{* Step_tac 1 *})
+ apply (simp)
+ apply (simp_all add:even_num_iff)
+ apply (drule lemma_even_mod_4_div_2[simplified])
+ apply(simp add: numeral_2_eq_2 real_divide_def)
+ apply (drule lemma_odd_mod_4_div_2 );
+ apply (simp add: numeral_2_eq_2 real_divide_def)
+ apply (auto intro: real_mult_le_lemma mult_right_mono simp add: est mult_pos_le mult_ac real_divide_def abs_mult abs_inverse power_abs[symmetric])
+ done
+qed
+
+end
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