diff --git a/core/build.sh b/core/build.sh
index 56acb50..5cbfc38 100755
--- a/core/build.sh
+++ b/core/build.sh
@@ -15,8 +15,8 @@ echo "- translating from Python to C"
 cython -f -3 --fast-fail -X embedsignature=True cython_types.pyx -o cython_types.c || die "translating"
 
 echo "- compiling and linking"
-gcc $CFLAGS -I/usr/include/python3.4 -pthread -c cython_types.c || die "compilation"
-gcc $LFLAGS -L/usr/lib -lpython3.4 cython_types.o -o cython_types.so || die "linking"
+gcc $CFLAGS -I/usr/include/python3.5m -pthread -c cython_types.c || die "compilation"
+gcc $LFLAGS -L/usr/lib -lpython3.5m cython_types.o -o cython_types.so || die "linking"
 rm -f cython_types.{c,o}
 
 echo "- done"
diff --git a/core/cython_types.pyx b/core/cython_types.pyx
index a881016..c3f569a 100644
--- a/core/cython_types.pyx
+++ b/core/cython_types.pyx
@@ -44,10 +44,7 @@ class map:
 		'''
 		
 		if source:
-			if len(source[0]) == len(source[1]):
-				self.keys, self.vals = source
-			else:
-				raise ValueError('over.core.types.map initialized with two sequences of different lengths')
+			self.keys, self.vals = zip(*source)
 		else:
 			self.keys = []
 			self.vals = []
diff --git a/core/m.py b/core/m.py
index 6c75076..2f36f5f 100644
--- a/core/m.py
+++ b/core/m.py
@@ -12,6 +12,7 @@ class compare_float:
 		self.eq = False
 		self.ge = True
 		self.gt = False
+		self.ne = False
 		
 		if A < (B - epsilon):
 			self.lt = True
@@ -22,6 +23,8 @@ class compare_float:
 		
 		if abs(A - B) < epsilon:
 			self.eq = True
+		else:
+			self.ne = True
 		
 		# convenience
 		self.less = self.lt
@@ -29,6 +32,7 @@ class compare_float:
 		self.equal = self.eq
 		self.greater_or_equal = self.ge
 		self.greater = self.gt
+		self.not_equal = self.ne
 
 if __name__ == '__main__':
 	x = compare_float(1, 2, 0.5)
diff --git a/core/python_types.py b/core/python_types.py
index 2a4cdeb..3b2c573 100644
--- a/core/python_types.py
+++ b/core/python_types.py
@@ -44,10 +44,7 @@ class map:
 		'''
 		
 		if source:
-			if len(source[0]) == len(source[1]):
-				self.keys, self.vals = source
-			else:
-				raise ValueError('over.core.types.map initialized with two sequences of different lengths')
+			self.keys, self.vals = zip(*source)
 		else:
 			self.keys = []
 			self.vals = []