diff --git a/smop/Makefile b/smop/Makefile
index 5c857340..3b21d3ed 100644
--- a/smop/Makefile
+++ b/smop/Makefile
@@ -1,51 +1,34 @@
-
 # for py3: make PYTHON=python3 CYTHON="cython -3" V=3.4
 
-VPATH = $(SCRIPTS)/strings $(SCRIPTS)/specfun
 OCTAVE = /home/lei/octave-4.0.2
 SCRIPTS = $(OCTAVE)/scripts
 
 CYTHON = cython
 PYTHON = python
-XFILES = -x inputParser.m,quadgk.m,quadl.m,triplequad.m,dblquad.m,reallog.m,nthroot.m,factorial.m
+#XFILES = -x inputParser.m,quadgk.m,quadl.m,triplequad.m,dblquad.m,uiputfile.m,uigetfile.m,qmr.m,installed_packages.m,stft.m,legend.m,__plt_get_axis_arg__.m,rotate.m,print.m,__ghostscript__.m,__gnuplot_print__.m,set.m,edit.m,what.m,usejava.m,javachk.m,__go_draw_axes__.m,interp3.m,interp2.m,interpn.m,randi.m,interp1.m,spdiags.m,importdata.m,stemleaf.m
 FLAGS  = 
-V = 2.7
-ALL = \*.m
-
-factorial.py: factorial.m
-	$(PYTHON) main.py -v $^ $(FLAGS) 
-all: mybench.py 
-	$(PYTHON) -c "import mybench ; mybench.mybench()"
-
-#octave.py: primes.m interp2.m meshgrid.m repmat.m
-#	$(PYTHON) main.py --callgraph $(FLAGS) $^ -r core -o $@
-#	dot -Tpdf -o G.pdf G.dot
 
-#test_primes: octave.py
-#	$(PYTHON) -c "import octave ; octave.primes(1000)"
+V = 2.7
 
-octave.py:
-	find $(SCRIPTS)/general $(SCRIPTS)/specfun -name \*.m | xargs python main.py -o $@  $(FLAGS) $(XFILES)
+all:
+	make -B FLAGS=     liboctave.py | wc
+	make -B FLAGS=-C   liboctave.py | wc
+	make -B FLAGS=-N   liboctave.py | wc
+	make -B FLAGS=-T   liboctave.py | wc
+	make -B FLAGS=-CN  liboctave.py | wc
+	make -B FLAGS=-TN  liboctave.py | wc
+	make -B FLAGS=-CT  liboctave.py | wc
+	make -B FLAGS=-CTN liboctave.py | wc
 
+liboctave.py:
+	find $(SCRIPTS) -name \*.m | xargs $(PYTHON) main.py -o $@ $(FLAGS) $(XFILES) $^
+	#$(PYTHON) $@
 
 clean:
 	rm -f a.* *.pyc solver.so solver.py octave.so
 
-solver.py: solver.m #r8_random.m octave.py
-	$(PYTHON) main.py $^ -o $@ 
-
-check: solver.py 
-	$(PYTHON) test_core.py
-	$(PYTHON) test_matlabarray.py
-	$(PYTHON) test_sparsearray.py
-	$(PYTHON) test_lexer.py 
-	$(PYTHON) test_solver.py
-#	$(PYTHON) test_primes.py
-
-#$(PYTHON) main.py $(FLAGS) -r core solver.m r8_random.m -o solver.py && python go.py
-#test:
-#	find $(SCRIPTS) -name $(ALL) | xargs python main.py $(FLAGS)
-
+regress:
+	make | sort -u | wc
 %.c: %.py
 	$(CYTHON) $^
 
@@ -53,7 +36,6 @@ check: solver.py
 	gcc -Wno-cpp -I /usr/include/python$V -O2 -shared -o $@ $^
 
 %.py: %.m
-	#smop $(FLAGS) -o $@ $^
 	$(PYTHON) main.py -o $@ $^
 	$(PYTHON) $@
 
diff --git a/smop/backend.py b/smop/backend.py
index 25c4883d..13f5c9aa 100644
--- a/smop/backend.py
+++ b/smop/backend.py
@@ -26,6 +26,7 @@
     "||": "or",
     "&&": "and",
     "^" : "**",
+    "**": "**",
     ".^": "**",
     "./": "/",
     ".*": "*",
@@ -125,15 +126,18 @@ def _backend(self,level=0):
 
 @extend(node.expr)
 def _backend(self,level=0):
-    if self.op in ("!","not"): # ???
-       return "not %s" % self.args[0]._backend()
-    if self.op in ("&","and"):
+    if self.op in ("!","~"): 
+       return "logical_not(%s)" % self.args[0]._backend()
+
+    if self.op == "&":
        return "logical_and(%s)" % self.args._backend()
+
     if self.op == "&&":
         return "%s and %s" % (self.args[0]._backend(),
                               self.args[1]._backend())
-    if self.op in ("|","or"):
+    if self.op == "|":
         return "logical_or(%s)" % self.args._backend()
+
     if self.op == "||":
         return "%s or %s" % (self.args[0]._backend(),
                              self.args[1]._backend())
diff --git a/smop/lexer.py b/smop/lexer.py
index 5e068267..f3675ddb 100644
--- a/smop/lexer.py
+++ b/smop/lexer.py
@@ -20,7 +20,7 @@ class IllegalCharacterError(Exception):
            "MINUS","MINUSMINUS","MINUSEQ","MUL","MULEQ","NE", "NEG",
            "NUMBER", "OR","OREQ", "OROR", "PLUS", "PLUSEQ","PLUSPLUS",
            "RBRACE", "RBRACKET", "RPAREN", "SEMI", "STRING",
-           "TRANSPOSE", "ERROR_STMT", "COMMENT", "END_FUNCTION", ]
+           "TRANSPOSE", "ERROR_STMT", "COMMENT", "END_FUNCTION","POW", ]
 
 reserved = {
     "break"                  : "BREAK",
@@ -73,6 +73,7 @@ def new():
     t_MINUSEQ     = r"\-="
     t_MINUSMINUS  = r"\--"
     t_MUL         = r"\*"
+    t_POW         = r"\*\*"
     t_MULEQ       = r"\*="
     t_NE          = r"(~=)|(!=)"
     t_NEG         = r"\~|\!"
diff --git a/smop/main.py b/smop/main.py
index be0e8033..5ff22d27 100644
--- a/smop/main.py
+++ b/smop/main.py
@@ -59,7 +59,7 @@ def main():
                 s = backend.backend(stmt_list)
                 print >> fp, s
         except Exception as e:
-            print e
+            print "\tFailed: ",options.filename
             if options.strict:
                 raise
 
diff --git a/smop/parse.py b/smop/parse.py
index 5fb64389..ed5ada9a 100644
--- a/smop/parse.py
+++ b/smop/parse.py
@@ -52,7 +52,7 @@ class syntax_error(error):
     ("left", "MUL","DIV","DOTMUL","DOTDIV","BACKSLASH"),
     ("right","UMINUS","NEG"),
     ("right","TRANSPOSE"),
-    ("right","EXP", "DOTEXP"),
+    ("right","EXP", "DOTEXP", "POW"),
     ("nonassoc","LPAREN","RPAREN","RBRACE","LBRACE"),
     ("left", "FIELD","DOT","PLUSPLUS","MINUSMINUS"),
     )
@@ -323,6 +323,7 @@ def p_expr2(p):
              | expr DOTMUL expr
              | expr DOTMULEQ expr
              | expr EQEQ expr
+             | expr POW expr
              | expr EXP expr
              | expr EXPEQ expr
              | expr GE expr
@@ -831,6 +832,10 @@ def p_while_stmt(p):
 
 @exceptions
 def p_error(p):
+    if p.type == "COMMENT":
+        #print "Discarded comment", p.value
+        parser.errok()
+        return
     raise syntax_error(p)
 
 parser = yacc.yacc(start="top")