diff --git a/doc/function/sort_list.txt b/doc/function/sort_list.txt
index c202ef12..426489c0 100644
--- a/doc/function/sort_list.txt
+++ b/doc/function/sort_list.txt
@@ -10,9 +10,12 @@ Optionally order by some other property.
 ! Parameter	Type			Description
 | @input@	[[type:list]] or [[type:set]]	List to sort.
 | @order_by@	[[type:function]] (optional)	Function to order by, for example when @order_by: {input.name}@ orders items by their name property.
+| @remove_duplicates@	[[type:boolean]]	DOC_MSE_VERSION: since 0.3.7
+			 			If @true@, keep only one copy of duplicate elements.
 
 --Examples--
 > sort_list([5,2,3,1,4])          ==  [1,2,3,4,5]
 > sort_list(["aaa","cccc","bb"])  ==  ["aaa","bb","cccc"]
-> sort_list(["aaa","cccc","bb"], order_by: {number_of_items(in:input)})
+> sort_list(["aaa","cccc","bb"], order_by: length)
 >                                 ==  ["bb","aaa","cccc"]
+> sort_list([1,2,1,2,2,3], remove_duplicates:true)  ==  [1,2,3]
diff --git a/doc/type/tagged_string.txt b/doc/type/tagged_string.txt
index 6111068d..c4c8008a 100644
--- a/doc/type/tagged_string.txt
+++ b/doc/type/tagged_string.txt
@@ -16,7 +16,7 @@ This is written as the character with code 1 in files.
 | @"<i>"@		The text inside the tag is italic.
 | @"<sym>"@		The text inside the tag is rendered as symbols, if a [[prop:style:symbol font]] is set for the text box.
 | @"<color:???>"@	The text inside the tag is rendered with the given [[type:color]].
-| @"<size:???>"@	The text inside the tag is scaled by the a factor, for example @"<size:2>text</size>"@ makes the text twice as large.
+| @"<size:???>"@	The text inside the tag is rendered with the given font size in points, for example @"<size:12>text</size>"@ makes the text 12 points. The text is scaled down proportianally when it does not fit in a text box and the @scale down to@ attribute allows it.
 | @"<line>"@		Line breaks inside this tag use the [[prop:style:line height line]], and they show a horizontal line.
 | @"<soft-line>"@	Line breaks inside this tag use the [[prop:style:soft line height]].
 | @"<atom>"@		An atomic piece of text. The cursor can never be inside it; it is selected as a whole.
diff --git a/src/script/functions/basic.cpp b/src/script/functions/basic.cpp
index eeb60608..ae86dac4 100644
--- a/src/script/functions/basic.cpp
+++ b/src/script/functions/basic.cpp
@@ -33,7 +33,26 @@ SCRIPT_FUNCTION(trace) {
 
 SCRIPT_FUNCTION(warning) {
 	SCRIPT_PARAM_C(String, input);
-	handle_warning(input, true);
+	SCRIPT_PARAM_DEFAULT_C(bool, condition, true);
+	if (condition) {
+		handle_warning(input, true);
+	}
+	return script_nil;
+}
+SCRIPT_FUNCTION(warning_if_neq) {
+	SCRIPT_PARAM_C(String, input);
+	SCRIPT_PARAM_N(ScriptValueP, SCRIPT_VAR__1, v1);
+	SCRIPT_PARAM_N(ScriptValueP, SCRIPT_VAR__2, v2);
+	if (!equal(v1,v2)) {
+		String s1 = _("?"), s2 = _("?");
+		try {
+			s1 = v1->toCode();
+		} catch (...) {}
+		try {
+			s2 = v2->toCode();
+		} catch (...) {}
+		handle_warning(input + s1 + _(" != ") + s2, true);
+	}
 	return script_nil;
 }
 
@@ -59,13 +78,17 @@ String format_input(const String& format, Context& ctx) {
 
 SCRIPT_FUNCTION(to_string) {
 	ScriptValueP format = ctx.getVariable(SCRIPT_VAR_format);
-	if (format && format->type() == SCRIPT_STRING) {
-		// format specifier. Be careful, the built in function 'format' has the same name
-		SCRIPT_RETURN(format_input(*format, ctx));
-	} else {
-		// simple conversion
-		SCRIPT_PARAM_C(String, input);
-		SCRIPT_RETURN(input);
+	try {
+		if (format && format->type() == SCRIPT_STRING) {
+			// format specifier. Be careful, the built in function 'format' has the same name
+			SCRIPT_RETURN(format_input(*format, ctx));
+		} else {
+			// simple conversion
+			SCRIPT_PARAM_C(String, input);
+			SCRIPT_RETURN(input);
+		}
+	} catch (const ScriptError& e) {
+		return new_intrusive1<ScriptDelayedError>(e);
 	}
 }
 
@@ -145,6 +168,11 @@ SCRIPT_FUNCTION(to_color) {
 	}
 }
 
+SCRIPT_FUNCTION(to_code) {
+	SCRIPT_PARAM_C(ScriptValueP, input);
+	SCRIPT_RETURN(input->toCode());
+}
+
 // ----------------------------------------------------------------------------- : Math
 
 SCRIPT_FUNCTION(abs) {
@@ -344,14 +372,20 @@ int position_in_vector(const ScriptValueP& of, const ScriptValueP& in, const Scr
 inline bool smart_less_first(const pair<String,ScriptValueP>& a, const pair<String,ScriptValueP>& b) {
 	return smart_less(a.first, b.first);
 }
+inline bool smart_equal_first(const pair<String,ScriptValueP>& a, const pair<String,ScriptValueP>& b) {
+	return smart_equal(a.first, b.first);
+}
 
 // sort a script list
-ScriptValueP sort_script(Context& ctx, const ScriptValueP& list, ScriptValue& order_by) {
+ScriptValueP sort_script(Context& ctx, const ScriptValueP& list, ScriptValue& order_by, bool remove_duplicates) {
 	ScriptType list_t = list->type();
 	if (list_t == SCRIPT_STRING) {
 		// sort a string
 		String s = list->toString();
 		sort(s.begin(), s.end());
+		if (remove_duplicates) {
+			s.erase( unique(s.begin(), s.end()), s.end() );
+		}
 		SCRIPT_RETURN(s);
 	} else {
 		// are we sorting a set?
@@ -364,6 +398,10 @@ ScriptValueP sort_script(Context& ctx, const ScriptValueP& list, ScriptValue& or
 			values.push_back(make_pair(order_by.eval(ctx)->toString(), v));
 		}
 		sort(values.begin(), values.end(), smart_less_first);
+		// unique
+		if (remove_duplicates) {
+			values.erase( unique(values.begin(), values.end(), smart_equal_first), values.end() );
+		}
 		// return collection
 		ScriptCustomCollectionP ret(new ScriptCustomCollection());
 		FOR_EACH(v, values) {
@@ -442,10 +480,12 @@ SCRIPT_FUNCTION(filter_list) {
 
 SCRIPT_FUNCTION(sort_list) {
 	SCRIPT_PARAM_C(ScriptValueP, input);
-	SCRIPT_PARAM_N(ScriptValueP, _("order by"), order_by);
-	return sort_script(ctx, input, *order_by);
+	SCRIPT_PARAM_DEFAULT_N(ScriptValueP, _("order by"), order_by, script_nil);
+	SCRIPT_PARAM_DEFAULT_N(bool, _("remove duplicates"), remove_duplicates, false);
+	return sort_script(ctx, input, *order_by, remove_duplicates);
 }
 
+
 SCRIPT_FUNCTION(random_shuffle) {
 	SCRIPT_PARAM_C(ScriptValueP, input);
 	// convert to CustomCollection
@@ -571,6 +611,7 @@ void init_script_basic_functions(Context& ctx) {
 	ctx.setVariable(_("to number"),            script_to_number);
 	ctx.setVariable(_("to boolean"),           script_to_boolean);
 	ctx.setVariable(_("to color"),             script_to_color);
+	ctx.setVariable(_("to code"),              script_to_code);
 	// math
 	ctx.setVariable(_("abs"),                  script_abs);
 	ctx.setVariable(_("random_real"),          script_random_real);
diff --git a/src/script/parser.cpp b/src/script/parser.cpp
index af19c339..d8b6a0cf 100644
--- a/src/script/parser.cpp
+++ b/src/script/parser.cpp
@@ -23,6 +23,7 @@ DECLARE_TYPEOF_COLLECTION(Variable);
 String read_utf8_line(wxInputStream& input, bool eat_bom = true, bool until_eof = false);
 
 extern ScriptValueP script_warning;
+extern ScriptValueP script_warning_if_neq;
 
 // ----------------------------------------------------------------------------- : Tokenizing : class
 
@@ -557,45 +558,30 @@ void parseExpr(TokenIterator& input, Script& script, Precedence minPrec) {
 				expectToken(input, _("("));
 				size_t start = input.peek().pos;
 				int line = input.getLineNumber();
+				size_t function_pos = script.getConstants().size();
+				script.addInstruction(I_PUSH_CONST, script_warning);
 				parseOper(input, script, PREC_ALL); // condition
 				size_t end = input.peek().pos;
 				String message = String::Format(_("Assertion failure on line %d:\n   expected: "), line) + input.getSourceCode(start,end);
 				expectToken(input, _(")"), &token);
 				if (script.getInstructions().back().instr == I_BINARY && script.getInstructions().back().instr2 == I_EQ) {
-					// compile "assert(x == y)" into "
+					// compile "assert(x == y)" into
+					//    warning_if_neq("condition", _1: x, _2: y)
 					message += _("\n   found: ");
-					script.getInstructions().pop_back();   // remove ==
-					script.addInstruction(I_DUP, 1);       // duplicate X
-					script.addInstruction(I_DUP, 1);       // duplicate Y
-					script.addInstruction(I_BINARY, I_EQ); //
-					unsigned jmpElse = script.addInstruction(I_JUMP_IF_NOT);	// jnz lbl_else
-					script.addInstruction(I_PUSH_CONST, script_nil);			// push nil
-					unsigned jmpEnd = script.addInstruction(I_JUMP);			// jump lbl_end
-					script.comeFrom(jmpElse);									// lbl_else:
-					script.addInstruction(I_PUSH_CONST, script_warning);		// push warning
-					script.addInstruction(I_PUSH_CONST, message);				//    push "condition"
-					script.addInstruction(I_DUP, 3);							//    duplicate X
-					script.addInstruction(I_BINARY, I_ADD);						//   add
-					script.addInstruction(I_PUSH_CONST, String(_(" != ")));		//   push " != "
-					script.addInstruction(I_BINARY, I_ADD);						//  add
-					script.addInstruction(I_DUP, 2);							//  duplicate Y
-					script.addInstruction(I_BINARY, I_ADD);						// add
-					script.addInstruction(I_CALL, 1);							// call
-					script.addInstruction(I_NOP,  SCRIPT_VAR_input);			// (input:)
-					script.comeFrom(jmpEnd);									// lbl_end:
-					script.addInstruction(I_BINARY, I_POP);						// pop Y_copy
-					script.addInstruction(I_BINARY, I_POP);						// pop X_copy
-				} else {
-					// compile into:  if condition then nil else warning("condition")
-					unsigned jmpElse = script.addInstruction(I_JUMP_IF_NOT);	// jnz lbl_else
-					script.addInstruction(I_PUSH_CONST, script_nil);			// push nil
-					unsigned jmpEnd = script.addInstruction(I_JUMP);			// jump lbl_end
-					script.comeFrom(jmpElse);									// lbl_else:
-					script.addInstruction(I_PUSH_CONST, script_warning);		// push warning
+					script.getConstants()[function_pos] = script_warning_if_neq;
+					script.getInstructions().pop_back();						// POP == instruction
 					script.addInstruction(I_PUSH_CONST, message);				// push "condition"
-					script.addInstruction(I_CALL, 1);							// call
+					script.addInstruction(I_CALL, 3);							// call
+					script.addInstruction(I_NOP,  SCRIPT_VAR__1);				// (_1:)
+					script.addInstruction(I_NOP,  SCRIPT_VAR__2);				// (_2:)
+					script.addInstruction(I_NOP,  SCRIPT_VAR_input);			// (input:)
+				} else {
+					// compile into:  warning("condition", condition: not condition)
+					script.addInstruction(I_UNARY, I_NOT);						// not
+					script.addInstruction(I_PUSH_CONST, message);				// push "condition"
+					script.addInstruction(I_CALL, 2);							// call
+					script.addInstruction(I_NOP,  SCRIPT_VAR_condition);		// (condition:)
 					script.addInstruction(I_NOP,  SCRIPT_VAR_input);			// (input:)
-					script.comeFrom(jmpEnd);									// lbl_end:
 				}
 			} else {
 				// variable
diff --git a/src/script/script.cpp b/src/script/script.cpp
index c22c49d1..4b17af3c 100644
--- a/src/script/script.cpp
+++ b/src/script/script.cpp
@@ -52,6 +52,8 @@ void init_script_variables() {
 	#define VarN(X,name) if (SCRIPT_VAR_##X != string_to_variable(name)) assert(false);
 	#define Var(X)       VarN(X,_(#X))
 	Var(input);
+	Var(_1);
+	Var(_2);
 	Var(in);
 	Var(match);
 	Var(replace);
@@ -73,6 +75,7 @@ void init_script_variables() {
 	Var(card);
 	Var(styling);
 	Var(value);
+	Var(condition);
 	assert(variables.size() == SCRIPT_VAR_CUSTOM_FIRST);
 }
 
diff --git a/src/script/script.hpp b/src/script/script.hpp
index 77ef22cf..1e6b092b 100644
--- a/src/script/script.hpp
+++ b/src/script/script.hpp
@@ -111,6 +111,8 @@ struct Instruction {
 // for faster lookup from code
 enum Variable
 {	SCRIPT_VAR_input
+,	SCRIPT_VAR__1
+,	SCRIPT_VAR__2
 ,	SCRIPT_VAR_in
 ,	SCRIPT_VAR_match
 ,	SCRIPT_VAR_replace
@@ -132,6 +134,7 @@ enum Variable
 ,	SCRIPT_VAR_card
 ,	SCRIPT_VAR_styling
 ,	SCRIPT_VAR_value
+,	SCRIPT_VAR_condition
 ,	SCRIPT_VAR_CUSTOM_FIRST // other variables start from here
 ,	SCRIPT_VAR_CUSTOM_LOTS = 0xFFFFFF // ensure that sizeof(Variable) is large enough
 };
diff --git a/src/script/to_value.hpp b/src/script/to_value.hpp
index f9275705..f7814eb6 100644
--- a/src/script/to_value.hpp
+++ b/src/script/to_value.hpp
@@ -95,6 +95,12 @@ ScriptValueP rangeIterator(int start, int end);
 
 // ----------------------------------------------------------------------------- : Collections
 
+class ScriptCollectionBase : public ScriptValue {
+  public:
+	virtual ScriptType type() const { return SCRIPT_COLLECTION; }
+	virtual String toCode() const;
+};
+
 // Iterator over a collection
 template <typename Collection>
 class ScriptCollectionIterator : public ScriptIterator {
@@ -114,10 +120,9 @@ class ScriptCollectionIterator : public ScriptIterator {
 
 /// Script value containing a collection
 template <typename Collection>
-class ScriptCollection : public ScriptValue {
+class ScriptCollection : public ScriptCollectionBase {
   public:
 	inline ScriptCollection(const Collection* v) : value(v) {}
-	virtual ScriptType type() const { return SCRIPT_COLLECTION; }
 	virtual String typeName() const { return _TYPE_1_("collection of", type_name(*value->begin())); }
 	virtual ScriptValueP getIndex(int index) const {
 		if (index >= 0 && index < (int)value->size()) {
@@ -190,9 +195,8 @@ class ScriptMap : public ScriptValue {
 // ----------------------------------------------------------------------------- : Collections : from script
 
 /// Script value containing a custom collection, returned from script functions
-class ScriptCustomCollection : public ScriptValue {
+class ScriptCustomCollection : public ScriptCollectionBase {
   public:
-	virtual ScriptType type() const { return SCRIPT_COLLECTION; }
 	virtual String typeName() const { return _TYPE_("collection"); }
 	virtual ScriptValueP getMember(const String& name) const;
 	virtual ScriptValueP getIndex(int index) const;
diff --git a/src/script/value.cpp b/src/script/value.cpp
index 49c61804..59268fbd 100644
--- a/src/script/value.cpp
+++ b/src/script/value.cpp
@@ -27,8 +27,9 @@ ScriptValueP ScriptValue::eval(Context&)                    const { return delay
 ScriptValueP ScriptValue::next()                                  { throw InternalError(_("Can't convert from ")+typeName()+_(" to iterator")); }
 ScriptValueP ScriptValue::makeIterator(const ScriptValueP&) const { return delayError(_ERROR_2_("can't convert", typeName(), _TYPE_("collection"))); }
 int          ScriptValue::itemCount()                       const { throw ScriptError(_ERROR_2_("can't convert", typeName(), _TYPE_("collection"))); }
+String       ScriptValue::toCode()                          const { return *this; }
 CompareWhat  ScriptValue::compareAs(String& compare_str, void const*& compare_ptr) const {
-	compare_str = toString();
+	compare_str = toCode();
 	return COMPARE_AS_STRING;
 }
 ScriptValueP ScriptValue::getMember(const String& name) const {
@@ -322,12 +323,36 @@ class ScriptNil : public ScriptValue {
 	virtual operator double() const { return 0.0; }
 	virtual operator int()    const { return 0; }
 	virtual operator bool()   const { return false; }
-	virtual ScriptValueP eval(Context&) const { return script_nil; } // nil() == nil
+	virtual ScriptValueP eval(Context& ctx) const {
+		// nil(input) == input
+		return ctx.getVariable(SCRIPT_VAR_input);
+	}
 };
 
 /// The preallocated nil value
 ScriptValueP script_nil(new ScriptNil);
 
+// ----------------------------------------------------------------------------- : Collection base
+
+String ScriptCollectionBase::toCode() const {
+	String ret = _("[");
+	bool first = true;
+	#ifdef USE_INTRUSIVE_PTR
+		// we can just turn this into a ScriptValueP
+		// TODO: remove thisP alltogether
+		ScriptValueP it = makeIterator(ScriptValueP(const_cast<ScriptValue*>((ScriptValue*)this)));
+	#else
+		#error "makeIterator needs a ScriptValueP :("
+	#endif
+	while (ScriptValueP v = it->next()) {
+		if (!first) ret += _(",");
+		first = false;
+		ret += v->toCode();
+	}
+	ret += _("]");
+	return ret;
+}
+
 // ----------------------------------------------------------------------------- : Custom collection
 
 // Iterator over a custom collection
diff --git a/src/script/value.hpp b/src/script/value.hpp
index d1420ff7..7908a279 100644
--- a/src/script/value.hpp
+++ b/src/script/value.hpp
@@ -67,6 +67,9 @@ class ScriptValue : public IntrusivePtrBaseWithDelete {
 	/// Convert this value to a color
 	virtual operator AColor() const;
 	
+	/// Script code to generate this value
+	virtual String toCode() const;
+	
 	/// Explicit overload to convert to a string
 	/** This is sometimes necessary, because wxString has an int constructor,
 	 *  which confuses gcc. */
diff --git a/src/util/string.cpp b/src/util/string.cpp
index bf1d6773..a85b559a 100644
--- a/src/util/string.cpp
+++ b/src/util/string.cpp
@@ -276,7 +276,7 @@ Char decompose_char2(Char c) {
 	}
 }
 
-bool smart_less(const String& sa, const String& sb) {
+int smart_compare(const String& sa, const String& sb) {
 	bool in_num = false; // are we inside a number?
 	bool lt = false;     // is sa less than sb?
 	bool eq = true;      // so far is everything equal?
@@ -295,12 +295,12 @@ bool smart_less(const String& sa, const String& sb) {
 			}
 		} else if (in_num && da) {
 			// comparing numbers, one is longer, therefore it is greater
-			return false;
+			return 1;
 		} else if (in_num && db) {
-			return true;
+			return -1;
 		} else if (in_num && !eq) {
 			// two numbers of the same length, but not equal
-			return lt;
+			return lt ? -1 : 1;
 		} else if (a != b) {
 			// not a number
 			eq = true; lt = false;
@@ -310,26 +310,26 @@ bool smart_less(const String& sa, const String& sb) {
 				// Decompose characters
 				Char la2 = decompose_char2(a), lb2 = decompose_char2(b);
 				// Compare
-				if (la < lb) return true;
-				if (la > lb) return false;
+				if (la < lb) return -1;
+				if (la > lb) return 1;
 				// Remaining from decomposition
 				if (la2 || lb2) {
 					if (la2) a = la2;
 					else {
-						if (++pa >= na) return false;
+						if (++pa >= na) return 1;
 						a = sa.GetChar(pa);
 					}
 					if (lb2) b = lb2;
 					else {
-						if (++pb >= nb) return true;
+						if (++pb >= nb) return -1;
 						b = sb.GetChar(pb);
 					}
 					goto next; // don't move to the next character in both strings
 				}
 			} else {
 				// control characters
-				if (a < b) return true;
-				else       return false;
+				if (a < b) return -1;
+				else       return 1;
 			}
 		}
 		in_num = da && db;
@@ -341,16 +341,23 @@ bool smart_less(const String& sa, const String& sb) {
 		if (na - pa < nb - pb) {
 			// number b continues?
 			Char b = sb.GetChar(pb);
-			if (isDigit(b) || eq) return true;  // b is longer
+			if (isDigit(b) || eq) return -1; // b is longer
 		} else if (na - pa > nb - pb) {
 			Char a = sa.GetChar(pa);
-			if (isDigit(a) || eq) return false; // a is longer
+			if (isDigit(a) || eq) return 1;  // a is longer
 		}
-		return lt; // compare numbers
+		return eq ? 0 : lt ? -1 : 1; // compare numbers
 	} else {
-		return na - pa < nb - pb; // outside number, shorter string comes first
+		return na - pa == nb - pb ? 0
+		     : na - pa <  nb - pb ? -1 : 1; // outside number, shorter string comes first
 	}
 }
+bool smart_less(const String& sa, const String& sb) {
+	return smart_compare(sa, sb) == -1;
+}
+bool smart_equal(const String& sa, const String& sb) {
+	return smart_compare(sa, sb) == 0;
+}
 
 bool starts_with(const String& str, const String& start) {
 	if (str.size() < start.size()) return false;
diff --git a/src/util/string.hpp b/src/util/string.hpp
index cd2fcf0c..1aec4cad 100644
--- a/src/util/string.hpp
+++ b/src/util/string.hpp
@@ -162,12 +162,18 @@ String remove_shortcut(const String&);
 
 // ----------------------------------------------------------------------------- : Comparing / finding
 
-/// Compare two strings, is the first less than the first?
+/// Compare two strings
 /** Uses a smart comparison algorithm that understands numbers. 
  *  The comparison is case insensitive.
  *  Doesn't handle leading zeros.
+ *
+ *  Returns -1 if a < b, 0 if they are equal, and 1 if a > b
  */
+int smart_compare(const String&, const String&);
+/// Compare two strings, is the first less than the first?
 bool smart_less(const String&, const String&);
+/// Compare two strings for equality
+bool smart_equal(const String&, const String&);
 
 /// Return whether str starts with start
 /** starts_with(a,b) == is_substr(a,0,b) */