Index: src/Parser/parser.yy
===================================================================
--- src/Parser/parser.yy	(revision e16eb4600c0da5cd33a501208772f6ae22d465fd)
+++ src/Parser/parser.yy	(revision 05c941a228c76fb58519369eb2f9219b18873e6b)
@@ -10,6 +10,6 @@
 // Created On       : Sat Sep  1 20:22:55 2001
 // Last Modified By : Peter A. Buhr
-// Last Modified On : Sat Oct  2 08:27:21 2021
-// Update Count     : 5080
+// Last Modified On : Fri Oct  8 06:57:16 2021
+// Update Count     : 5086
 //
 
@@ -1091,7 +1091,7 @@
 	comma_expression_opt ';'
 		{ $$ = new StatementNode( build_expr( $1 ) ); }
-	| MUTEX '@' comma_expression ';'
-		// { $$ = new StatementNode( build_mutex( nullptr, new StatementNode( build_expr( $3 ) ) ) ); }
-		{ SemanticError( yylloc, "Mutex expression is currently unimplemented." ); $$ = nullptr; }
+	| MUTEX '(' ')' comma_expression ';'
+		{ $$ = new StatementNode( build_mutex( nullptr, new StatementNode( build_expr( $4 ) ) ) ); }
+		// { SemanticError( yylloc, "Mutex expression is currently unimplemented." ); $$ = nullptr; }
 	;