diff --git a/topics/extraction/sdf2bgf/Main.asf b/topics/extraction/sdf2bgf/Main.asf
index e2a8ea4d..a25a4e01 100644
--- a/topics/extraction/sdf2bgf/Main.asf
+++ b/topics/extraction/sdf2bgf/Main.asf
@@ -37,6 +37,25 @@ trafoSymbols() =
   <epsilon/>
 </bgf:expression>
 
+[transform-a-labelled-production]
+&C1 := sort2chardata(&N1),
+&E2 := trafoSymbols(&Ss1),
+&C0 := guessLabel(&Acs1)
+=====================
+trafoProd ( &Ss1 -> &N1 {&Acs1} ) =
+<bgf:production>
+  &C0
+  <nonterminal>&C1</nonterminal>
+  &E2
+</bgf:production>
+
+[transform-empty-definition-of-nonterminal]
+trafoSymbols() = 
+<bgf:expression>
+  <epsilon/>
+</bgf:expression>
+
+
 [transform-definition-that-is-not-a-sequence]
 trafoSymbols(&S1) = trafoSymbol(&S1)
 
@@ -99,3 +118,18 @@ trafoSymbol(&S1?) =
   <bgf:expression>
     <optional>&E1</optional>
   </bgf:expression>
+
+[cons-to-label-only-cons]
+guessLabel(cons(&I1)) = <label>idcon2chardata(&I1)</label>
+
+[cons-to-label-cons-etc]
+guessLabel(cons(&I1),&Acs2) = <label>idcon2chardata(&I1)</label>
+
+[cons-to-label-empty]
+guessLabel() = 
+
+[default-cons-to-label-no-cons]
+guessLabel(&A1) = 
+
+[default-cons-to-label-head-is-not-cons]
+guessLabel(&A1,&Acs2) = guessLabel(&Acs2)
diff --git a/topics/extraction/sdf2bgf/Main.sdf b/topics/extraction/sdf2bgf/Main.sdf
index 0c4265dd..92fb5f03 100644
--- a/topics/extraction/sdf2bgf/Main.sdf
+++ b/topics/extraction/sdf2bgf/Main.sdf
@@ -26,22 +26,25 @@ module Main
 	trafoSymbol(Symbol) -> Element
 	trafoSymbols(Symbols) -> Element
 	mapTrafoSymbol(Symbols) -> Content*
+	guessLabel({Attribute ","}*) -> Content?
 
     variables
-	"&A" [0-9]+ -> Attribute
+	"&A"  [0-9]+ -> Attribute
 	"&A*" [0-9]+ -> Attribute*
 	"&As" [0-9]+ -> Attributes
-	"&C" [0-9]+ -> Content
+	"&Acs"[0-9]+ -> {Attribute ","}*
+	"&C"  [0-9]+ -> Content
 	"&C*" [0-9]+ -> Content*
-	"&E" [0-9]+ -> Element
-	%% "&E*" [0-9]+ -> Element* %% Useless because of lack of covariance
-	"&G" [0-9]+ -> Grammar
-	"&M" [0-9]+ -> Module
-	"&N" [0-9]+ -> Sort
-	"&P" [0-9]+ -> Production
+	"&E"  [0-9]+ -> Element
+%%	"&E*" [0-9]+ -> Element* %% Useless because of lack of covariance
+	"&G"  [0-9]+ -> Grammar
+	"&M"  [0-9]+ -> Module
+	"&N"  [0-9]+ -> Sort
+	"&P"  [0-9]+ -> Production
 	"&P*" [0-9]+ -> Production*
 	"&Ps" [0-9]+ -> Productions
-	"&S" [0-9]+ -> Symbol
+	"&S"  [0-9]+ -> Symbol
 	"&S*" [0-9]+ -> Symbol*
 	"&Ss" [0-9]+ -> Symbols
-	"&Z" [0-9]+ -> StrCon
+	"&Z"  [0-9]+ -> StrCon
+	"&I"  [0-9]+ -> IdCon
diff --git a/topics/extraction/sdf2bgf/Tokens.asf b/topics/extraction/sdf2bgf/Tokens.asf
index a0d5026a..0f25a782 100644
--- a/topics/extraction/sdf2bgf/Tokens.asf
+++ b/topics/extraction/sdf2bgf/Tokens.asf
@@ -21,3 +21,14 @@ strchar(&Chr1) := &StrChar1,
 chardata(&Char1 &Chars1) := strcon2chardata(strcon(\" &StrChar+2 \"))
 ===========================================================
 strcon2chardata(strcon(\" &StrChar1 &StrChar+2 \")) = chardata(&Chr1 &Char1 &Chars1)
+
+[idcon-of-length-1]
+idcon2chardata(idcon(&IdHead1)) = chardata(&IdHead1)
+
+[idcon-of-length-2]
+idcon2chardata(idcon(&IdHead1 &Middle1)) = chardata(&IdHead1 &Middle1)
+
+[idcon-of-length-greater-than-2]
+chardata(&Char1 &Chars1) := idcon2chardata(idcon(&IdHead1 &Middles1))
+===============================================================
+idcon2chardata(idcon(&IdHead1 &Middle1 &Middles1)) = chardata(&Char1 &Middle1 &Chars1)
diff --git a/topics/extraction/sdf2bgf/Tokens.sdf b/topics/extraction/sdf2bgf/Tokens.sdf
index be43d91e..009f8bf3 100644
--- a/topics/extraction/sdf2bgf/Tokens.sdf
+++ b/topics/extraction/sdf2bgf/Tokens.sdf
@@ -4,18 +4,18 @@ imports
 	languages/sdf2/syntax/Sorts
 	languages/xml/syntax/XML
 	basic/StrCon
+	basic/IdentifierCon
 
 exports
-
-    sorts CharData
-
-    context-free syntax
-	sort2chardata(Sort) -> CharData
-	strcon2chardata(StrCon) -> CharData
+	sorts
+		CharData
+	context-free syntax
+		sort2chardata(Sort)	-> CharData
+		strcon2chardata(StrCon)	-> CharData
+		idcon2chardata(IdCon)	-> CharData
 
 hiddens
-
-    lexical syntax
+	lexical syntax
     	%% Let's remind ourselves of the relevant lexical syntax.
                   %%
                   %%   1. languages/sdf2/syntax/Sorts
@@ -35,13 +35,14 @@ hiddens
                   %%     ~[\0-\31\n\t\"\\] -> StrChar {cons("normal")}
                   %%     [\"] chars:StrChar* [\"] -> StrCon  {cons("default")}
 
-    lexical variables
-	"&Head" [0-9]* -> [A-Z]		%% Part of Sort
-	"&Middle" [0-9]* -> [A-Za-z0-9\-]	%% Part of Sort
-	"&Middles" [0-9]* -> [A-Za-z0-9\-]*	%% Part of Sort
-	"&Last" [0-9]* -> [A-Za-z0-9]		%% Part of Sort
-                  "&Char" [0-9]* -> ~[\<\&]		%% Part of CharData
-                  "&Chars" [0-9]* -> ~[\<\&]*		%% Part of CharData
-	"&StrChar" [0-9]* -> StrChar		%% Part of StrCon
-	"&StrChar+" [0-9]* -> StrChar+	%% Part of StrCon
-	"&Chr" [0-9]* -> ~[\0-\31\n\t\"\\\<\&]
+	lexical variables
+		"&Head" [0-9]* -> [A-Z]		%% Part of Sort
+		"&IdHead" [0-9]* -> [A-Za-z]	%% Part of IdCon
+		"&Middle" [0-9]* -> [A-Za-z0-9\-]	%% Part of Sort
+		"&Middles" [0-9]* -> [A-Za-z0-9\-]*	%% Part of Sort
+		"&Last" [0-9]* -> [A-Za-z0-9]		%% Part of Sort
+		"&Char" [0-9]* -> ~[\<\&]		%% Part of CharData
+		"&Chars" [0-9]* -> ~[\<\&]*		%% Part of CharData
+		"&StrChar" [0-9]* -> StrChar		%% Part of StrCon
+		"&StrChar+" [0-9]* -> StrChar+	%% Part of StrCon
+		"&Chr" [0-9]* -> ~[\0-\31\n\t\"\\\<\&]