add exceptions

diff --git a/simple_v_extension.mdwn b/simple_v_extension.mdwn
index 9111087d7668d9a9eaa073ef15f585d37db43a76..634d205e9b9a8c45a216383d3e0f4298f75a854e 100644 (file)
--- a/simple_v_extension.mdwn
+++ b/simple_v_extension.mdwn
@@ -694,6 +694,13 @@ translates effectively to:
 | RSUB8 rt, ra, rb   | Signed Halving sub        | |
 | URSUB8 rt, ra, rb  | Unsigned Halving sub      | |
 
+# Exceptions
+
+> What does an ADD of two different-sized vectors do in simple-V?
+
+* if the two source operands are not the same, throw an exception.
+* if the destination operand is also a vector, and the source is longer
+  than the destination, throw an exception.
 
 # Impementing V on top of Simple-V