--- a/src/HOL/ex/Lagrange.thy Sun Jan 18 13:58:17 2009 +0100
+++ b/src/HOL/ex/Lagrange.thy Wed Jan 28 16:29:16 2009 +0100
@@ -35,7 +35,7 @@
sq (x1*y2 + x2*y1 + x3*y4 - x4*y3) +
sq (x1*y3 - x2*y4 + x3*y1 + x4*y2) +
sq (x1*y4 + x2*y3 - x3*y2 + x4*y1)"
-by (simp add: sq_def ring_simps)
+by (simp add: sq_def algebra_simps)
text {* A challenge by John Harrison. Takes about 12s on a 1.6GHz machine. *}
@@ -51,6 +51,6 @@
sq (p1*u2 + q1*t2 - r1*w2 + s1*v2 - t1*q2 + u1*p2 - v1*s2 + w1*r2) +
sq (p1*v2 + q1*w2 + r1*t2 - s1*u2 - t1*r2 + u1*s2 + v1*p2 - w1*q2) +
sq (p1*w2 - q1*v2 + r1*u2 + s1*t2 - t1*s2 - u1*r2 + v1*q2 + w1*p2)"
-by (simp add: sq_def ring_simps)
+by (simp add: sq_def algebra_simps)
end