changeset 36096 | abc6a2ea4b88 |
parent 35028 | 108662d50512 |
child 36349 | 39be26d1bc28 |
--- a/src/HOL/Series.thy Fri Apr 02 13:33:48 2010 +0200 +++ b/src/HOL/Series.thy Wed Apr 07 19:17:10 2010 +0200 @@ -381,7 +381,7 @@ shows "norm x < 1 \<Longrightarrow> summable (\<lambda>n. x ^ n)" by (rule geometric_sums [THEN sums_summable]) -lemma half: "0 < 1 / (2::'a::{number_ring,division_by_zero,ordered_field})" +lemma half: "0 < 1 / (2::'a::{number_ring,division_by_zero,linordered_field})" by arith lemma power_half_series: "(\<lambda>n. (1/2::real)^Suc n) sums 1"