src/HOL/Library/Word.thy
changeset 23477 f4b83f03cac9
parent 23431 25ca91279a9b
child 23821 2acd9d79d855
equal deleted inserted replaced
23476:839db6346cc8 23477:f4b83f03cac9
   441           by (induct "length xs",simp_all)
   441           by (induct "length xs",simp_all)
   442         hence "bitval x * 2 ^ (length xs + length l2) + bv_to_nat xs * 2 ^ length l2 =
   442         hence "bitval x * 2 ^ (length xs + length l2) + bv_to_nat xs * 2 ^ length l2 =
   443           bitval x * 2 ^ length xs * 2 ^ length l2 + bv_to_nat xs * 2 ^ length l2"
   443           bitval x * 2 ^ length xs * 2 ^ length l2 + bv_to_nat xs * 2 ^ length l2"
   444           by simp
   444           by simp
   445         also have "... = (bitval x * 2 ^ length xs + bv_to_nat xs) * 2 ^ length l2"
   445         also have "... = (bitval x * 2 ^ length xs + bv_to_nat xs) * 2 ^ length l2"
   446           by (simp add: ring_distrib)
   446           by (simp add: ring_distribs)
   447         finally show ?thesis .
   447         finally show ?thesis .
   448       qed
   448       qed
   449     qed
   449     qed
   450   qed
   450   qed
   451   thus ?thesis ..
   451   thus ?thesis ..