add while loop syntax fix

nefelitav · nefelitav · commit ce0f7340e84f · 2024-06-16T17:01:52.000+02:00
diff --git a/src/expressions.rst b/src/expressions.rst
@@ -3870,7 +3870,7 @@ While Loops
        $$while$$ IterationExpression LoopBody
 
    IterationExpression ::=
-       Expression
+       SubjectExpression
 
 .. rubric:: Legality Rules
 
