src/HOL/Binomial.thy
changeset 62481 b5d8e57826df
parent 62378 85ed00c1fe7c
child 63040 eb4ddd18d635
--- a/src/HOL/Binomial.thy	Tue Mar 01 10:32:55 2016 +0100
+++ b/src/HOL/Binomial.thy	Tue Mar 01 10:36:19 2016 +0100
@@ -697,9 +697,8 @@
   then show ?thesis by simp
 next
   case False
-  from this setprod_constant[of "{0 .. n - 1}" "- (1:: 'a)"]
-  have eq: "(- (1::'a)) ^ n = setprod (\<lambda>i. - 1) {0 .. n - 1}"
-    by auto
+  then have eq: "(- 1) ^ n = (\<Prod>i = 0..n - 1. - 1)"
+    by (auto simp add: setprod_constant)
   from False show ?thesis
     by (simp add: pochhammer_def gbinomial_def field_simps
       eq setprod.distrib[symmetric])