From 86d77d779fdc21fd0af2f1482bdae57c5cc162c0 Mon Sep 17 00:00:00 2001
From: grammarware <vadim@grammarware.net>
Date: Wed, 9 May 2012 08:50:31 +0000
Subject: [PATCH] added xbgf:split, a reverse of xbgf:unite

git-svn-id: https://slps.svn.sourceforge.net/svnroot/slps@1195 ab42f6e0-554d-0410-b580-99e487e6eeb2
---
 shared/prolog/readXbgf.pro                    | 10 +++++
 shared/prolog/xbgf1.pro                       | 45 +++++++++++++++++++
 shared/xsd/xbgf.xsd                           | 16 +++++++
 .../transformation/xbgf/tests/split1.baseline | 24 ++++++++++
 topics/transformation/xbgf/tests/split1.bgf   | 24 ++++++++++
 topics/transformation/xbgf/tests/split1.xbgf  | 13 ++++++
 .../transformation/xbgf/tests/split2.baseline | 24 ++++++++++
 topics/transformation/xbgf/tests/split2.bgf   | 24 ++++++++++
 topics/transformation/xbgf/tests/split2.xbgf  | 13 ++++++
 .../transformation/xbgf/tests/split3.baseline | 24 ++++++++++
 topics/transformation/xbgf/tests/split3.bgf   | 24 ++++++++++
 topics/transformation/xbgf/tests/split3.xbgf  | 14 ++++++
 .../transformation/xbgf/tests/split4.baseline | 24 ++++++++++
 topics/transformation/xbgf/tests/split4.bgf   | 24 ++++++++++
 topics/transformation/xbgf/tests/split4.xbgf  | 14 ++++++
 .../xbgf/tests/unite_eq.baseline              | 17 ++++---
 topics/transformation/xbgf/tests/unite_eq.bgf | 25 ++++++-----
 .../transformation/xbgf/tests/unite_eq.xbgf   | 13 +++---
 .../xbgf/tests/unite_normal.baseline          | 38 ++++++++--------
 .../xbgf/tests/unite_normal.bgf               | 38 ++++++++--------
 .../xbgf/tests/unite_normal.xbgf              | 14 +++---
 21 files changed, 388 insertions(+), 74 deletions(-)
 create mode 100644 topics/transformation/xbgf/tests/split1.baseline
 create mode 100644 topics/transformation/xbgf/tests/split1.bgf
 create mode 100644 topics/transformation/xbgf/tests/split1.xbgf
 create mode 100644 topics/transformation/xbgf/tests/split2.baseline
 create mode 100644 topics/transformation/xbgf/tests/split2.bgf
 create mode 100644 topics/transformation/xbgf/tests/split2.xbgf
 create mode 100644 topics/transformation/xbgf/tests/split3.baseline
 create mode 100644 topics/transformation/xbgf/tests/split3.bgf
 create mode 100644 topics/transformation/xbgf/tests/split3.xbgf
 create mode 100644 topics/transformation/xbgf/tests/split4.baseline
 create mode 100644 topics/transformation/xbgf/tests/split4.bgf
 create mode 100644 topics/transformation/xbgf/tests/split4.xbgf

diff --git a/shared/prolog/readXbgf.pro b/shared/prolog/readXbgf.pro
index 0abfcea7..f2e0b83c 100644
--- a/shared/prolog/readXbgf.pro
+++ b/shared/prolog/readXbgf.pro
@@ -318,6 +318,16 @@ xml2xbgf(T,detour(P2))
     child(name(bgf:production),T,P1),
     xmlToP(P1,P2).
 
+xml2xbgf(T,split(N,Ps2,Ls2))
+ :-
+    self(name(xbgf:split),T),
+    child(name(nonterminal),T,Nonterminal),
+    children(name(bgf:production),T,Ps1),
+    children(name(label),T,Ls1),
+    content(Nonterminal,N),
+    maplist(xmlToP,Ps1,Ps2),
+    maplist(content,Ls1,Ls2).
+
 xml2xbgf(T,stripL(L))
  :-
     self(name(xbgf:strip),T),
diff --git a/shared/prolog/xbgf1.pro b/shared/prolog/xbgf1.pro
index 71d2f066..b39914c3 100644
--- a/shared/prolog/xbgf1.pro
+++ b/shared/prolog/xbgf1.pro
@@ -1294,6 +1294,51 @@ detour(P1,g(Rs,Ps1),g(Rs,Ps2))
       [N]),
 	append(Ps1,[P1],Ps2).
 
+%
+% p([l(split)], f, ','([n(n), n(n)]))
+%
+% Nonterminal splitting, a form of "de-unification"
+%
+% TODO: works only on labels, should eventually be implemented for all kinds of scopes/contexts
+%
+split(N1,Ps0,Ls1,g(Rs,Ps1),g(Rs,Ps2))
+ :-
+    allNs(g(Rs,Ps1),Ns1),
+    definedNs(g([],Ps0),[N0]),
+	require(
+       (member(N1,Ns1)),
+       'Source name ~q for splitting must not be fresh.',
+       [N1]),
+	require(
+       (\+ member(N0,Ns1)),
+       'Target name ~q for splitting must be fresh.',
+       [N0]),
+    changelhs(N0,N1,Ps0,Ps0p),
+    removeprods(Ps0p,g(Rs,Ps1),g(Rs,Ps3)),
+    import(Ps0,g(Rs,Ps3),g(Rs,Ps4)),
+    replaceLs(n(N1),n(N0),Ls1,g(Rs,Ps4),g(Rs,Ps2)).
+
+changelhs(_,_,[],[]).
+changelhs(N1,N2,[P1|Ps1],[P2|Ps2])
+ :- 
+    P1 = p(L,N3,X),
+    (
+      N1 == N3,
+	  P2 = p(L,N2,X)
+	;
+	  P2 = p(L,N3,X)
+	),
+    changelhs(N1,N2,Ps1,Ps2).
+
+removeprods([],G1,G1).
+removeprods([P0|Ps0],g(Rs,Ps1),g(Rs,Ps3)) :- removeV(P0,g(Rs,Ps1),g(Rs,Ps2)), removeprods(Ps0,g(Rs,Ps2),g(Rs,Ps3)).
+
+replaceLs(_,_,[],G1,G1).
+replaceLs(X1,X2,[L1|Ls],g(Rs,Ps1),g(Rs,Ps3))
+ :- 
+    replaceL(X1,X2,L1,g(Rs,Ps1),g(Rs,Ps2)),
+    replaceLs(X1,X2,Ls,g(Rs,Ps2),g(Rs,Ps3)).
+
 %
 % p([l(stripL)], f, n(l))
 % p([l(stripLs)], f, true)
diff --git a/shared/xsd/xbgf.xsd b/shared/xsd/xbgf.xsd
index ba2f17a8..c0f5aba1 100644
--- a/shared/xsd/xbgf.xsd
+++ b/shared/xsd/xbgf.xsd
@@ -167,6 +167,7 @@
       <xsd:element ref="xbgf:disappear"/>
       <xsd:element ref="xbgf:narrow"/>
       <xsd:element ref="xbgf:downgrade"/>
+      <xsd:element ref="xbgf:split"/>
     </xsd:choice>
   </xsd:group>
   <xsd:group name="concrete-revising-transformation">
@@ -1162,6 +1163,21 @@
     </xsd:complexType>
   </xsd:element>
 
+  <xsd:element name="split">
+    <xsd:annotation>
+      <xsd:documentation>
+        The reverse of <ldf:keyword>unite</ldf:keyword>.
+      </xsd:documentation>
+    </xsd:annotation>
+    <xsd:complexType>
+      <xsd:sequence>
+        <xsd:element name="nonterminal" type="bgf:nonterminal"/>
+        <xsd:element ref="bgf:production" maxOccurs="unbounded"/>
+        <xsd:group ref="xbgf:scope"  minOccurs="0"  maxOccurs="unbounded"/>
+      </xsd:sequence>
+    </xsd:complexType>
+  </xsd:element>
+
   <xsd:element name="equate">
     <xsd:annotation>
       <xsd:documentation>
diff --git a/topics/transformation/xbgf/tests/split1.baseline b/topics/transformation/xbgf/tests/split1.baseline
new file mode 100644
index 00000000..c6d8692a
--- /dev/null
+++ b/topics/transformation/xbgf/tests/split1.baseline
@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="utf-8"?>
+<bgf:grammar xmlns:bgf="http://planet-sl.org/bgf">
+	<bgf:production>
+		<label>A</label>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<terminal>a</terminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<label>B</label>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<terminal>b</terminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<label>D</label>
+		<nonterminal>bar</nonterminal>
+		<bgf:expression>
+			<terminal>d</terminal>
+		</bgf:expression>
+	</bgf:production>
+</bgf:grammar>
diff --git a/topics/transformation/xbgf/tests/split1.bgf b/topics/transformation/xbgf/tests/split1.bgf
new file mode 100644
index 00000000..1055d83c
--- /dev/null
+++ b/topics/transformation/xbgf/tests/split1.bgf
@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<bgf:grammar xmlns:bgf="http://planet-sl.org/bgf">
+	<bgf:production>
+		<label>A</label>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<terminal>a</terminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<label>B</label>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<terminal>b</terminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<label>D</label>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<terminal>d</terminal>
+		</bgf:expression>
+	</bgf:production>
+</bgf:grammar>
diff --git a/topics/transformation/xbgf/tests/split1.xbgf b/topics/transformation/xbgf/tests/split1.xbgf
new file mode 100644
index 00000000..654fc87d
--- /dev/null
+++ b/topics/transformation/xbgf/tests/split1.xbgf
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<xbgf:sequence xmlns:bgf="http://planet-sl.org/bgf" xmlns:xbgf="http://planet-sl.org/xbgf">
+	<xbgf:split>
+		<nonterminal>foo</nonterminal>
+		<bgf:production>
+			<label>D</label>
+			<nonterminal>bar</nonterminal>
+			<bgf:expression>
+				<terminal>d</terminal>
+			</bgf:expression>
+		</bgf:production>
+	</xbgf:split>
+</xbgf:sequence>
diff --git a/topics/transformation/xbgf/tests/split2.baseline b/topics/transformation/xbgf/tests/split2.baseline
new file mode 100644
index 00000000..4720b147
--- /dev/null
+++ b/topics/transformation/xbgf/tests/split2.baseline
@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="utf-8"?>
+<bgf:grammar xmlns:bgf="http://planet-sl.org/bgf">
+	<bgf:production>
+		<label>A</label>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<terminal>a</terminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<label>B</label>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<terminal>b</terminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<label>D</label>
+		<nonterminal>bar</nonterminal>
+		<bgf:expression>
+			<nonterminal>foo</nonterminal>
+		</bgf:expression>
+	</bgf:production>
+</bgf:grammar>
diff --git a/topics/transformation/xbgf/tests/split2.bgf b/topics/transformation/xbgf/tests/split2.bgf
new file mode 100644
index 00000000..74270c56
--- /dev/null
+++ b/topics/transformation/xbgf/tests/split2.bgf
@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<bgf:grammar xmlns:bgf="http://planet-sl.org/bgf">
+	<bgf:production>
+		<label>A</label>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<terminal>a</terminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<label>B</label>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<terminal>b</terminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<label>D</label>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<nonterminal>foo</nonterminal>
+		</bgf:expression>
+	</bgf:production>
+</bgf:grammar>
diff --git a/topics/transformation/xbgf/tests/split2.xbgf b/topics/transformation/xbgf/tests/split2.xbgf
new file mode 100644
index 00000000..7fb2c0c0
--- /dev/null
+++ b/topics/transformation/xbgf/tests/split2.xbgf
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<xbgf:sequence xmlns:bgf="http://planet-sl.org/bgf" xmlns:xbgf="http://planet-sl.org/xbgf">
+	<xbgf:split>
+		<nonterminal>foo</nonterminal>
+		<bgf:production>
+			<label>D</label>
+			<nonterminal>bar</nonterminal>
+			<bgf:expression>
+				<nonterminal>foo</nonterminal>
+			</bgf:expression>
+		</bgf:production>
+	</xbgf:split>
+</xbgf:sequence>
diff --git a/topics/transformation/xbgf/tests/split3.baseline b/topics/transformation/xbgf/tests/split3.baseline
new file mode 100644
index 00000000..c0c8d007
--- /dev/null
+++ b/topics/transformation/xbgf/tests/split3.baseline
@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="utf-8"?>
+<bgf:grammar xmlns:bgf="http://planet-sl.org/bgf">
+	<bgf:production>
+		<label>A</label>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<terminal>a</terminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<label>B</label>
+		<nonterminal>wez</nonterminal>
+		<bgf:expression>
+			<nonterminal>bar</nonterminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<label>D</label>
+		<nonterminal>bar</nonterminal>
+		<bgf:expression>
+			<nonterminal>foo</nonterminal>
+		</bgf:expression>
+	</bgf:production>
+</bgf:grammar>
diff --git a/topics/transformation/xbgf/tests/split3.bgf b/topics/transformation/xbgf/tests/split3.bgf
new file mode 100644
index 00000000..18ea3220
--- /dev/null
+++ b/topics/transformation/xbgf/tests/split3.bgf
@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<bgf:grammar xmlns:bgf="http://planet-sl.org/bgf">
+	<bgf:production>
+		<label>A</label>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<terminal>a</terminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<label>B</label>
+		<nonterminal>wez</nonterminal>
+		<bgf:expression>
+			<nonterminal>foo</nonterminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<label>D</label>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<nonterminal>foo</nonterminal>
+		</bgf:expression>
+	</bgf:production>
+</bgf:grammar>
diff --git a/topics/transformation/xbgf/tests/split3.xbgf b/topics/transformation/xbgf/tests/split3.xbgf
new file mode 100644
index 00000000..b44f23ae
--- /dev/null
+++ b/topics/transformation/xbgf/tests/split3.xbgf
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+<xbgf:sequence xmlns:bgf="http://planet-sl.org/bgf" xmlns:xbgf="http://planet-sl.org/xbgf">
+	<xbgf:split>
+		<nonterminal>foo</nonterminal>
+		<bgf:production>
+			<label>D</label>
+			<nonterminal>bar</nonterminal>
+			<bgf:expression>
+				<nonterminal>foo</nonterminal>
+			</bgf:expression>
+		</bgf:production>
+		<label>B</label>
+	</xbgf:split>
+</xbgf:sequence>
diff --git a/topics/transformation/xbgf/tests/split4.baseline b/topics/transformation/xbgf/tests/split4.baseline
new file mode 100644
index 00000000..cec0952f
--- /dev/null
+++ b/topics/transformation/xbgf/tests/split4.baseline
@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="utf-8"?>
+<bgf:grammar xmlns:bgf="http://planet-sl.org/bgf">
+	<bgf:production>
+		<label>A</label>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<terminal>a</terminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<label>B</label>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<nonterminal>bar</nonterminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<label>D</label>
+		<nonterminal>bar</nonterminal>
+		<bgf:expression>
+			<nonterminal>foo</nonterminal>
+		</bgf:expression>
+	</bgf:production>
+</bgf:grammar>
diff --git a/topics/transformation/xbgf/tests/split4.bgf b/topics/transformation/xbgf/tests/split4.bgf
new file mode 100644
index 00000000..e096fb87
--- /dev/null
+++ b/topics/transformation/xbgf/tests/split4.bgf
@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<bgf:grammar xmlns:bgf="http://planet-sl.org/bgf">
+	<bgf:production>
+		<label>A</label>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<terminal>a</terminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<label>B</label>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<nonterminal>foo</nonterminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<label>D</label>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<nonterminal>foo</nonterminal>
+		</bgf:expression>
+	</bgf:production>
+</bgf:grammar>
diff --git a/topics/transformation/xbgf/tests/split4.xbgf b/topics/transformation/xbgf/tests/split4.xbgf
new file mode 100644
index 00000000..b44f23ae
--- /dev/null
+++ b/topics/transformation/xbgf/tests/split4.xbgf
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+<xbgf:sequence xmlns:bgf="http://planet-sl.org/bgf" xmlns:xbgf="http://planet-sl.org/xbgf">
+	<xbgf:split>
+		<nonterminal>foo</nonterminal>
+		<bgf:production>
+			<label>D</label>
+			<nonterminal>bar</nonterminal>
+			<bgf:expression>
+				<nonterminal>foo</nonterminal>
+			</bgf:expression>
+		</bgf:production>
+		<label>B</label>
+	</xbgf:split>
+</xbgf:sequence>
diff --git a/topics/transformation/xbgf/tests/unite_eq.baseline b/topics/transformation/xbgf/tests/unite_eq.baseline
index 90169a4d..928f0927 100644
--- a/topics/transformation/xbgf/tests/unite_eq.baseline
+++ b/topics/transformation/xbgf/tests/unite_eq.baseline
@@ -1,10 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
-
-<xns1:grammar xmlns:xns1="http://planet-sl.org/bgf">
-  <xns1:production>
-    <nonterminal>a</nonterminal>
-    <xns1:expression>
-      <epsilon/>
-    </xns1:expression>
-  </xns1:production>
-</xns1:grammar>
\ No newline at end of file
+<bgf:grammar xmlns:bgf="http://planet-sl.org/bgf">
+	<bgf:production>
+		<nonterminal>a</nonterminal>
+		<bgf:expression>
+			<epsilon/>
+		</bgf:expression>
+	</bgf:production>
+</bgf:grammar>
diff --git a/topics/transformation/xbgf/tests/unite_eq.bgf b/topics/transformation/xbgf/tests/unite_eq.bgf
index 7d8750c0..bb7365c5 100644
--- a/topics/transformation/xbgf/tests/unite_eq.bgf
+++ b/topics/transformation/xbgf/tests/unite_eq.bgf
@@ -1,14 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
 <bgf:grammar xmlns:bgf="http://planet-sl.org/bgf">
-  <bgf:production>
-    <nonterminal>a</nonterminal>
-    <bgf:expression>
-      <epsilon/>
-    </bgf:expression>
-  </bgf:production>
-  <bgf:production>
-    <nonterminal>b</nonterminal>
-    <bgf:expression>
-      <epsilon/>
-    </bgf:expression>
-  </bgf:production>
+	<bgf:production>
+		<nonterminal>a</nonterminal>
+		<bgf:expression>
+			<epsilon/>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<nonterminal>b</nonterminal>
+		<bgf:expression>
+			<epsilon/>
+		</bgf:expression>
+	</bgf:production>
 </bgf:grammar>
diff --git a/topics/transformation/xbgf/tests/unite_eq.xbgf b/topics/transformation/xbgf/tests/unite_eq.xbgf
index 29062fdd..0cca42d1 100644
--- a/topics/transformation/xbgf/tests/unite_eq.xbgf
+++ b/topics/transformation/xbgf/tests/unite_eq.xbgf
@@ -1,8 +1,7 @@
-<xbgf:sequence
-  xmlns:bgf="http://planet-sl.org/bgf"
-  xmlns:xbgf="http://planet-sl.org/xbgf">
-  <xbgf:unite>
-    <add>b</add>
-    <to>a</to>
-  </xbgf:unite>
+<?xml version="1.0" encoding="UTF-8"?>
+<xbgf:sequence xmlns:bgf="http://planet-sl.org/bgf" xmlns:xbgf="http://planet-sl.org/xbgf">
+	<xbgf:unite>
+		<add>b</add>
+		<to>a</to>
+	</xbgf:unite>
 </xbgf:sequence>
diff --git a/topics/transformation/xbgf/tests/unite_normal.baseline b/topics/transformation/xbgf/tests/unite_normal.baseline
index c7470897..9c22b8b0 100644
--- a/topics/transformation/xbgf/tests/unite_normal.baseline
+++ b/topics/transformation/xbgf/tests/unite_normal.baseline
@@ -1,21 +1,21 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <bgf:grammar xmlns:bgf="http://planet-sl.org/bgf">
-  <bgf:production>
-    <nonterminal>foo</nonterminal>
-    <bgf:expression>
-      <terminal>a</terminal>
-    </bgf:expression>
-  </bgf:production>
-  <bgf:production>
-    <nonterminal>foo</nonterminal>
-    <bgf:expression>
-      <terminal>b</terminal>
-    </bgf:expression>
-  </bgf:production>
-  <bgf:production>
-    <nonterminal>foo</nonterminal>
-    <bgf:expression>
-      <terminal>d</terminal>
-    </bgf:expression>
-  </bgf:production>
-</bgf:grammar>
\ No newline at end of file
+	<bgf:production>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<terminal>a</terminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<terminal>b</terminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<terminal>d</terminal>
+		</bgf:expression>
+	</bgf:production>
+</bgf:grammar>
diff --git a/topics/transformation/xbgf/tests/unite_normal.bgf b/topics/transformation/xbgf/tests/unite_normal.bgf
index d81ee594..8bfe0335 100644
--- a/topics/transformation/xbgf/tests/unite_normal.bgf
+++ b/topics/transformation/xbgf/tests/unite_normal.bgf
@@ -1,21 +1,21 @@
 <?xml version="1.0" encoding="utf-8"?>
 <bgf:grammar xmlns:bgf="http://planet-sl.org/bgf">
-  <bgf:production>
-    <nonterminal>foo</nonterminal>
-    <bgf:expression>
-      <terminal>a</terminal>
-    </bgf:expression>
-  </bgf:production>
-  <bgf:production>
-    <nonterminal>foo</nonterminal>
-    <bgf:expression>
-      <terminal>b</terminal>
-    </bgf:expression>
-  </bgf:production>
-  <bgf:production>
-    <nonterminal>bar</nonterminal>
-    <bgf:expression>
-      <terminal>d</terminal>
-    </bgf:expression>
-  </bgf:production>
-</bgf:grammar>
+	<bgf:production>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<terminal>a</terminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<nonterminal>foo</nonterminal>
+		<bgf:expression>
+			<terminal>b</terminal>
+		</bgf:expression>
+	</bgf:production>
+	<bgf:production>
+		<nonterminal>bar</nonterminal>
+		<bgf:expression>
+			<terminal>d</terminal>
+		</bgf:expression>
+	</bgf:production>
+</bgf:grammar>
diff --git a/topics/transformation/xbgf/tests/unite_normal.xbgf b/topics/transformation/xbgf/tests/unite_normal.xbgf
index 192779ef..6d9961d8 100644
--- a/topics/transformation/xbgf/tests/unite_normal.xbgf
+++ b/topics/transformation/xbgf/tests/unite_normal.xbgf
@@ -1,9 +1,7 @@
-<?xml version="1.0" encoding="utf-8"?>
-<xbgf:sequence
-  xmlns:bgf="http://planet-sl.org/bgf"
-  xmlns:xbgf="http://planet-sl.org/xbgf">
-  <xbgf:unite>
-    <add>bar</add>
-    <to>foo</to>
-  </xbgf:unite>
+<?xml version="1.0" encoding="utf-8"?>
+<xbgf:sequence xmlns:bgf="http://planet-sl.org/bgf" xmlns:xbgf="http://planet-sl.org/xbgf">
+	<xbgf:unite>
+		<add>bar</add>
+		<to>foo</to>
+	</xbgf:unite>
 </xbgf:sequence>