Index: src/Parser/parser.yy
===================================================================
--- src/Parser/parser.yy	(revision 1076d05688c3384e8cffb420e43cc293bc3d3d7c)
+++ src/Parser/parser.yy	(revision 0a6d8204aa07464088764b1d42a540ea42e521ad)
@@ -10,6 +10,6 @@
 // Created On       : Sat Sep  1 20:22:55 2001
 // Last Modified By : Peter A. Buhr
-// Last Modified On : Fri Mar  6 17:26:45 2020
-// Update Count     : 4474
+// Last Modified On : Mon Apr 27 12:25:42 2020
+// Update Count     : 4483
 //
 
@@ -966,7 +966,11 @@
 
 tuple_expression_list:
-	assignment_expression_opt
-	| tuple_expression_list ',' assignment_expression_opt
+	assignment_expression
+	| '@'												// CFA
+		{ SemanticError( yylloc, "Eliding tuple element with '@' is currently unimplemented." ); $$ = nullptr; }
+	| tuple_expression_list ',' assignment_expression
 		{ $$ = (ExpressionNode *)($1->set_last( $3 )); }
+	| tuple_expression_list ',' '@'
+		{ SemanticError( yylloc, "Eliding tuple element with '@' is currently unimplemented." ); $$ = nullptr; }
 	;