diff --git a/src/mathed/InsetMath.h b/src/mathed/InsetMath.h
index f60602c5fe..6b178a7a2d 100644
--- a/src/mathed/InsetMath.h
+++ b/src/mathed/InsetMath.h
@@ -31,7 +31,8 @@ enum HullType {
 	hullXXAlignAt,
 	hullFlAlign,
 	hullMultline,
-	hullGather
+	hullGather,
+	hullRegexp
 };
 
 HullType hullType(docstring const & name);
diff --git a/src/mathed/InsetMathGrid.cpp b/src/mathed/InsetMathGrid.cpp
index f3058c54c1..e14f70be2b 100644
--- a/src/mathed/InsetMathGrid.cpp
+++ b/src/mathed/InsetMathGrid.cpp
@@ -980,20 +980,27 @@ void InsetMathGrid::mathmlize(MathStream & os) const
 
 
 void InsetMathGrid::write(WriteStream & os) const
+{
+	write(os, 0, 0, nrows(), ncols());
+}
+
+void InsetMathGrid::write(WriteStream & os,
+			  row_type beg_row, col_type beg_col,
+			  row_type end_row, col_type end_col) const
 {
 	MathEnsurer ensurer(os, false);
 	docstring eol;
-	for (row_type row = 0; row < nrows(); ++row) {
+	for (row_type row = beg_row; row < end_row; ++row) {
 		os << verboseHLine(rowinfo_[row].lines_);
 		// don't write & and empty cells at end of line
 		col_type lastcol = 0;
 		bool emptyline = true;
-		for (col_type col = 0; col < ncols(); ++col)
+		for (col_type col = beg_col; col < end_col; ++col)
 			if (!cell(index(row, col)).empty()) {
 				lastcol = col + 1;
 				emptyline = false;
 			}
-		for (col_type col = 0; col < lastcol; ++col) {
+		for (col_type col = beg_col; col < end_col; ++col) {
 			os << cell(index(row, col));
 			if (os.pendingBrace())
 				ModeSpecifier specifier(os, TEXT_MODE);
@@ -1003,9 +1010,10 @@ void InsetMathGrid::write(WriteStream & os) const
 		os << eol;
 		// append newline only if line wasn't completely empty
 		// and this was not the last line in the grid
-		if (!emptyline && row + 1 < nrows())
+		if (!emptyline && row + 1 < end_row)
 			os << "\n";
 	}
+	// @TODO use end_row instead of nrows() ?
 	docstring const s = verboseHLine(rowinfo_[nrows()].lines_);
 	if (!s.empty()) {
 		if (eol.empty()) {
diff --git a/src/mathed/InsetMathGrid.h b/src/mathed/InsetMathGrid.h
index 437654c864..f085f99f1a 100644
--- a/src/mathed/InsetMathGrid.h
+++ b/src/mathed/InsetMathGrid.h
@@ -210,6 +210,10 @@ public:
 	///
 	void write(WriteStream & os) const;
 	///
+	void write(WriteStream & os,
+		   row_type beg_row, col_type beg_col,
+		   row_type end_row, col_type end_col) const;
+	///
 	void normalize(NormalStream &) const;
 	///
 	//void maple(MapleStream &) const;
diff --git a/src/mathed/InsetMathHull.cpp b/src/mathed/InsetMathHull.cpp
index 8496734ca8..99bb45fc0a 100644
--- a/src/mathed/InsetMathHull.cpp
+++ b/src/mathed/InsetMathHull.cpp
@@ -118,7 +118,8 @@ HullType hullType(docstring const & s)
 	if (s == "multline")  return hullMultline;
 	if (s == "gather")    return hullGather;
 	if (s == "flalign")   return hullFlAlign;
-	lyxerr << "unknown hull type '" << to_utf8(s) << "'" << endl;
+	if (s == "regexp")    return hullRegexp;
+  	lyxerr << "unknown hull type '" << to_utf8(s) << "'" << endl;
 	return HullType(-1);
 }
 
@@ -137,7 +138,8 @@ docstring hullName(HullType type)
 		case hullMultline:   return from_ascii("multline");
 		case hullGather:     return from_ascii("gather");
 		case hullFlAlign:    return from_ascii("flalign");
-		default:
+		case hullRegexp:     return from_ascii("regexp");
+ 		default:
 			lyxerr << "unknown hull type '" << type << "'" << endl;
 			return from_ascii("none");
 	}
@@ -556,10 +558,10 @@ bool InsetMathHull::ams() const
 
 Inset::DisplayType InsetMathHull::display() const
 {
-	return (type_ != hullSimple && type_ != hullNone) ? AlignCenter : Inline;
+	return (type_ != hullSimple && type_ != hullNone
+		&& type_ != hullRegexp) ? AlignCenter : Inline;
 }
 
-
 bool InsetMathHull::numberedType() const
 {
 	if (type_ == hullNone)
@@ -568,6 +570,8 @@ bool InsetMathHull::numberedType() const
 		return false;
 	if (type_ == hullXXAlignAt)
 		return false;
+	if (type_ == hullRegexp)
+		return false;
 	for (row_type row = 0; row < nrows(); ++row)
 		if (!nonum_[row])
 			return true;
@@ -631,6 +635,10 @@ void InsetMathHull::header_write(WriteStream & os) const
 		  << '{' << static_cast<unsigned int>((ncols() + 1)/2) << "}\n";
 		break;
 
+	case hullRegexp:
+		os << "\\regexp{";
+		break;
+
 	default:
 		os << "\\begin{unknown" << star(n) << '}';
 		break;
@@ -672,6 +680,10 @@ void InsetMathHull::footer_write(WriteStream & os) const
 		os << "\\end{" << hullName(type_) << "}\n";
 		break;
 
+	case hullRegexp:
+		os << "}";
+		break;
+
 	default:
 		os << "\\end{unknown" << star(n) << '}';
 		break;
diff --git a/src/mathed/InsetMathHull.h b/src/mathed/InsetMathHull.h
index 2b3d305bcc..9f850b240e 100644
--- a/src/mathed/InsetMathHull.h
+++ b/src/mathed/InsetMathHull.h
@@ -111,6 +111,10 @@ public:
 	///
 	void write(std::ostream & os) const;
 	///
+	void header_write(WriteStream &) const;
+	///
+	void footer_write(WriteStream &) const;
+	///
 	void read(Lexer & lex);
 	///
 	bool readQuiet(Lexer & lex);
@@ -157,10 +161,6 @@ private:
 	///
 	void validate1(LaTeXFeatures & features);
 	///
-	void header_write(WriteStream &) const;
-	///
-	void footer_write(WriteStream &) const;
-	///
 	docstring nicelabel(row_type row) const;
 	///
 	void doExtern(Cursor & cur, FuncRequest & func);
diff --git a/src/mathed/InsetMathNest.cpp b/src/mathed/InsetMathNest.cpp
index 9e1b63496b..7df9cf92a8 100644
--- a/src/mathed/InsetMathNest.cpp
+++ b/src/mathed/InsetMathNest.cpp
@@ -964,6 +964,23 @@ void InsetMathNest::doDispatch(Cursor & cur, FuncRequest & cmd)
 		break;
 	}
 
+	case LFUN_REGEXP_MODE: {
+		InsetMathHull * i = dynamic_cast<InsetMathHull *>(cur.inset().asInsetMath());
+		if (i && i->getType() == hullRegexp) {
+			cur.message(_("Already in regexp mode"));
+			break;
+		}
+		cur.macroModeClose();
+		docstring const save_selection = grabAndEraseSelection(cur);
+		selClearOrDel(cur);
+		cur.plainInsert(MathAtom(new InsetMathHull(hullRegexp)));
+		cur.posBackward();
+		cur.pushBackward(*cur.nextInset());
+		cur.niceInsert(save_selection);
+		cur.message(_("Regexp editor mode"));
+		break;
+	}
+
 	case LFUN_MATH_SIZE: {
 		FuncRequest fr = FuncRequest(LFUN_MATH_INSERT, cmd.argument());
 		doDispatch(cur, fr);
diff --git a/src/mathed/MathFactory.cpp b/src/mathed/MathFactory.cpp
index 1eea247a3c..d12ac0aa56 100644
--- a/src/mathed/MathFactory.cpp
+++ b/src/mathed/MathFactory.cpp
@@ -41,6 +41,7 @@
 #include "InsetMathTabular.h"
 #include "InsetMathUnderset.h"
 #include "InsetMathUnknown.h"
+#include "InsetMathHull.h"
 #include "InsetMathXArrow.h"
 #include "InsetMathXYMatrix.h"
 #include "MacroTable.h"
@@ -462,6 +463,9 @@ MathAtom createInsetMath(docstring const & s)
 	if (isSpecialChar(s))
 		return MathAtom(new InsetMathSpecialChar(s));
 
+	if (s == "regexp")
+		return MathAtom(new InsetMathHull(hullRegexp));
+
 	return MathAtom(new MathMacro(s));
 }