diff --git a/data-store/src/main/antlr/org/lucares/pdb/datastore/lang/PdbLang.g4 b/data-store/src/main/antlr/org/lucares/pdb/datastore/lang/PdbLang.g4
index d00d796..8cd66d6 100644
--- a/data-store/src/main/antlr/org/lucares/pdb/datastore/lang/PdbLang.g4
+++ b/data-store/src/main/antlr/org/lucares/pdb/datastore/lang/PdbLang.g4
@@ -35,7 +35,7 @@ equal : EQUAL ;
 
 AND        : 'and' ;
 OR         : 'or' ;
-NOT        : '!';
+NOT        : 'not' | '!';
 EQUAL      : '=' ;
 IN         : 'in' ;
 LPAREN     : '(' ;
diff --git a/data-store/src/test/java/org/lucares/pdb/datastore/internal/ProposerTest.java b/data-store/src/test/java/org/lucares/pdb/datastore/internal/ProposerTest.java
index 9acf431..3eb61cd 100644
--- a/data-store/src/test/java/org/lucares/pdb/datastore/internal/ProposerTest.java
+++ b/data-store/src/test/java/org/lucares/pdb/datastore/internal/ProposerTest.java
@@ -200,39 +200,62 @@ public class ProposerTest {
 	}
 
 	public void testProposalOnEmptyKeyPrefix() throws Exception {
-		assertProposals("name=* and ", ResultMode.FULL_VALUES, 11, //
-				new Proposal("name", "name=* and name=* ", true, "name=* and name=", 16), //
-				new Proposal("bird", "name=* and bird=* ", true, "name=* and bird=", 16), //
-				new Proposal("dog", "name=* and dog=* ", true, "name=* and dog=", 15), //
+		assertProposals("name=* and |", ResultMode.FULL_VALUES, //
+				proposal("name", "name=* and name=* ", "name=* and name=|"), //
+				proposal("bird", "name=* and bird=* ", "name=* and bird=|"), //
+				proposal("dog", "name=* and dog=* ", "name=* and dog=|"), //
 				// TODO it is wrong to return those two, because there are no values with name
 				// and type|address, but I'll leave this for now, because this is a different
 				// issue
-				new Proposal("method", "name=* and method=* ", true, "name=* and method=", 18), //
-				new Proposal("source", "name=* and source=* ", true, "name=* and source=", 18)//
+				proposal("method", "name=* and method=* ", "name=* and method=|"), //
+				proposal("source", "name=* and source=* ", "name=* and source=|")//
 		);
 	}
 
 	public void testProposalWithWildcards() throws Exception {
-		assertProposals("name=*im", ResultMode.FULL_VALUES, 8, //
-				new Proposal("Tim", "name=Tim", true, "name=Tim", 8), //
-				new Proposal("Timothy", "name=Timothy", true, "name=Timothy", 12)//
-		);
 
+		assertProposals("name=*im|", ResultMode.FULL_VALUES, //
+				proposal("Tim", "name=Tim", "name=Tim|"), //
+				proposal("Timothy", "name=Timothy", "name=Timothy|")//
+		);
 	}
 
 	public void testProposalWithAndExpression() throws Exception {
-		assertProposals("name=*im and bird=eagle", ResultMode.FULL_VALUES, 8, //
-				new Proposal("Tim", "name=Tim and bird=eagle", true, "name=Tim and bird=eagle", 8), //
-				new Proposal("Timothy", "name=Timothy and bird=eagle", true, "name=Timothy and bird=eagle", 12)//
+		assertProposals("name=*im| and bird=eagle", ResultMode.FULL_VALUES, //
+				proposal("Tim", "name=Tim and bird=eagle", "name=Tim| and bird=eagle"), //
+				proposal("Timothy", "name=Timothy and bird=eagle", "name=Timothy| and bird=eagle")//
 		);
 
-		assertProposals("name=*im and bird=eagle,pigeon", ResultMode.FULL_VALUES, 8, //
-				new Proposal("Tim", "name=Tim and bird=eagle,pigeon", true, "name=Tim and bird=eagle,pigeon", 8), //
-				new Proposal("Timothy", "name=Timothy and bird=eagle,pigeon", true,
-						"name=Timothy and bird=eagle,pigeon", 12)//
+		assertProposals("name=*im| and bird=eagle,pigeon", ResultMode.FULL_VALUES, //
+				proposal("Tim", "name=Tim and bird=eagle,pigeon", "name=Tim| and bird=eagle,pigeon"), //
+				proposal("Timothy", "name=Timothy and bird=eagle,pigeon", "name=Timothy| and bird=eagle,pigeon")//
 		);
 	}
 
+	public void testProposalWithAndNotExpression() throws Exception {
+		assertProposals("name=Tim and ! dog=labrador and bird=|", ResultMode.FULL_VALUES, //
+				proposal("eagle", "name=Tim and ! dog=labrador and bird=eagle",
+						"name=Tim and ! dog=labrador and bird=eagle|") //
+		);
+		assertProposals("name=Tim and not dog=labrador and bird=|", ResultMode.FULL_VALUES, //
+				proposal("eagle", "name=Tim and not dog=labrador and bird=eagle",
+						"name=Tim and not dog=labrador and bird=eagle|") //
+		);
+	}
+
+	private Proposal proposal(final String proposedTag, final String proposedQuery, final String newQuery) {
+		final String newQueryWithoutCaretMarker = newQuery.replace("|", "");
+		final int newCaretPosition = newQuery.indexOf('|');
+		return new Proposal(proposedTag, proposedQuery, true, newQueryWithoutCaretMarker, newCaretPosition);
+	}
+
+	private void assertProposals(final String query, final ResultMode resultMode, final Proposal... expected)
+			throws InterruptedException {
+		final int caretIndex = query.indexOf("|");
+		final String q = query.replace("|", "");
+		assertProposals(q, resultMode, caretIndex, expected);
+	}
+
 	private void assertProposals(final String query, final ResultMode resultMode, final int caretIndex,
 			final Proposal... expected) throws InterruptedException {