diff --git a/lib/src/api/SymbolicRon.gf b/lib/src/api/SymbolicRon.gf
index 748025880..0f93fe910 100644
--- a/lib/src/api/SymbolicRon.gf
+++ b/lib/src/api/SymbolicRon.gf
@@ -1,5 +1,5 @@
 --# -path=.:present:mathematical:prelude
 
-resource SymbolicRon = {} -- Symbolic with 
---  (Symbol = SymbolRon),
---  (Grammar = GrammarRon) ;
+resource SymbolicRon = Symbolic with 
+  (Symbol = SymbolRon),
+  (Grammar = GrammarRon) ;