Limit XOR & IFF to 2 arguments in schema

These connectives are not intuitive with more than 2 args. More reasoning: open-psa/mef#59 Issue #231
rakhimov · Jan 23, 2018 · 6c121bc · 6c121bc
1 parent bfffd20
commit 6c121bc
Showing 1 changed file with 4 additions and 6 deletions.
diff --git a/share/input.rng b/share/input.rng
@@ -624,14 +624,12 @@
         </oneOrMore>
       </element>
       <element name="xor">
-        <oneOrMore>
-          <ref name="argument"/>
-        </oneOrMore>
+        <ref name="argument"/>
+        <ref name="argument"/>
       </element>
       <element name="iff">
-        <oneOrMore>
-          <ref name="argument"/>
-        </oneOrMore>
+        <ref name="argument"/>
+        <ref name="argument"/>
       </element>
       <element name="nand">
         <oneOrMore>