diff --git a/lemon/Makefile.am b/lemon/Makefile.am
--- a/lemon/Makefile.am
+++ b/lemon/Makefile.am
@@ -7,34 +7,34 @@
 lib_LTLIBRARIES += lemon/libemon.la
 
 lemon_libemon_la_SOURCES = \
-        lemon/arg_parser.cc \
-        lemon/base.cc \
-        lemon/color.cc \
-        lemon/random.cc
+	lemon/arg_parser.cc \
+	lemon/base.cc \
+	lemon/color.cc \
+	lemon/random.cc
 
 #lemon_libemon_la_CXXFLAGS = $(GLPK_CFLAGS) $(CPLEX_CFLAGS) $(SOPLEX_CXXFLAGS) $(AM_CXXFLAGS)
 #lemon_libemon_la_LDFLAGS = $(GLPK_LIBS) $(CPLEX_LIBS) $(SOPLEX_LIBS)
 
 lemon_HEADERS += \
 	lemon/adaptors.h \
-        lemon/arg_parser.h \
+	lemon/arg_parser.h \
 	lemon/assert.h \
-        lemon/bfs.h \
-        lemon/bin_heap.h \
-        lemon/circulation.h \
-        lemon/color.h \
+	lemon/bfs.h \
+	lemon/bin_heap.h \
+	lemon/circulation.h \
+	lemon/color.h \
 	lemon/concept_check.h \
-        lemon/counter.h \
+	lemon/counter.h \
 	lemon/core.h \
-        lemon/dfs.h \
-        lemon/dijkstra.h \
-        lemon/dim2.h \
-        lemon/dimacs.h \
+	lemon/dfs.h \
+	lemon/dijkstra.h \
+	lemon/dim2.h \
+	lemon/dimacs.h \
 	lemon/elevator.h \
 	lemon/error.h \
 	lemon/full_graph.h \
-        lemon/graph_to_eps.h \
-        lemon/grid_graph.h \
+	lemon/graph_to_eps.h \
+	lemon/grid_graph.h \
 	lemon/hypercube_graph.h \
 	lemon/kruskal.h \
 	lemon/hao_orlin.h \
@@ -47,20 +47,20 @@
 	lemon/nauty_reader.h \
 	lemon/path.h \
 	lemon/preflow.h \
-        lemon/random.h \
+	lemon/random.h \
 	lemon/smart_graph.h \
 	lemon/suurballe.h \
-        lemon/time_measure.h \
-        lemon/tolerance.h \
+	lemon/time_measure.h \
+	lemon/tolerance.h \
 	lemon/unionfind.h
 
 bits_HEADERS += \
 	lemon/bits/alteration_notifier.h \
 	lemon/bits/array_map.h \
 	lemon/bits/base_extender.h \
-        lemon/bits/bezier.h \
+	lemon/bits/bezier.h \
 	lemon/bits/default_map.h \
-        lemon/bits/enable_if.h \
+	lemon/bits/enable_if.h \
 	lemon/bits/graph_adaptor_extender.h \
 	lemon/bits/graph_extender.h \
 	lemon/bits/map_extender.h \