diff --git a/arden_types.py b/arden_types.py
index cee8992..132afbe 100644
--- a/arden_types.py
+++ b/arden_types.py
@@ -37,6 +37,13 @@ class BaseType(ABC):
     def TIME(self):
         return self.time
     
+    def WHERE(self,other):
+        if isinstance(other, ListType):
+            return ListType([self for b_item in other.value if b_item.value==True])
+        if isinstance(other, BoolType) and other:
+            return self
+        return NullType()
+    
 
 class NumType(BaseType):
     def __init__(self, value: (int, float)):
@@ -77,31 +84,31 @@ class NumType(BaseType):
     def __gt__(self, other):
         if isinstance(other, NumType):
             return BoolType(self.value > other.value)
-        return NullType
+        return NullType()
     
     def __lt__(self, other):
         if isinstance(other, NumType):
             return BoolType(self.value < other.value)
-        return NullType
+        return NullType()
     
     def __ge__(self, other):
         if isinstance(other, NumType):
             return BoolType(self.value >= other.value)
         if isinstance(other, ListType):
             return ListType([self >= item  for item in other.value])
-        return NullType
+        return NullType()
     
     def __le__(self, other):
         if isinstance(other, NumType):
             return BoolType(self.value <= other.value)
         if isinstance(other, ListType):
             return ListType([self <= item  for item in other.value])
-        return NullType
+        return NullType()
     
     def __pow__(self, other):
         if isinstance(other, NumType):
             return NumType(self.value ** other.value)
-        return NullType
+        return NullType()
     
     def __neg__(self):
         return NumType(-self.value)
@@ -156,7 +163,7 @@ class BoolType(BaseType):
     def __and__(self,other):
         if isinstance(other, BoolType):
             return BoolType(self.value and other.value)
-        return NullType
+        return NullType()
     
     def NOT(self):
         return ~self
@@ -174,52 +181,54 @@ class ListType(BaseType):
     def __gt__(self, other):
         if isinstance(other, NumType):
             return ListType([item > other for item in self.value])
-        return NullType
+        return NullType()
     
     def __lt__(self, other):
         if isinstance(other, NumType):
             return ListType([item < other for item in self.value])
-        return NullType
+        return NullType()
     
     def __ge__(self, other):
         if isinstance(other, NumType):
             return ListType([item >= other for item in self.value])
         if isinstance(other, ListType) and len(self.value) == len(other.value):
             return ListType([a_item >= b_item for a_item, b_item in zip(self.value, other.value)])
-        return NullType
+        return NullType()
     
     def __le__(self, other):
         if isinstance(other, NumType):
             return ListType([item <= other for item in self.value])
         if isinstance(other, ListType) and len(self.value) == len(other.value):
             return ListType([a_item <= b_item for a_item, b_item in zip(self.value, other.value)])
-        return NullType
+        return NullType()
     
     def __and__(self,other):
         if isinstance(other, BoolType) or isinstance(other, NumType):
             return ListType([item and other for item in self.value])
         if isinstance(other, ListType) and len(self.value) == len(other.value):
             return ListType([a_item and b_item for a_item, b_item in zip(self.value, other.value)])
-        return NullType
+        return NullType()
 
     def __or__(self,other):
         if isinstance(other, BoolType) or isinstance(other, NumType):
             return ListType([item or other for item in self.value])
         if isinstance(other, ListType) and len(self.value) == len(other.value):
             return ListType([a_item or b_item for a_item, b_item in zip(self.value, other.value)])
-        return NullType
+        return NullType()
 
     def __truediv__(self,other):
         if isinstance(other, NumType):
             return ListType([item / other for item in self.value])
         if isinstance(other, ListType) and len(self.value) == len(other.value):
             return ListType([a_item / b_item for a_item, b_item in zip(self.value, other.value)])
-        return NullType
+        return NullType()
     
     def WHERE(self,other):
         if isinstance(other, ListType) and len(self.value) == len(other.value):
-            return ListType([a_item for a_item, b_item in zip(self.value, other.value) if b_item])
-        return NullType
+            return ListType([a_item for a_item, b_item in zip(self.value, other.value) if b_item.value==True])
+        if isinstance(other, BoolType) and other:
+            return self
+        return NullType()
     
     def IS(self,a,invert=False):
         if a is NumType:
@@ -262,12 +271,12 @@ class DateType(BaseType):
     def __gt__(self, other):
         if isinstance(other, DateType):
             return BoolType(self.value > other.value)
-        return NullType
+        return NullType()
     
     def __lt__(self, other):
         if isinstance(other, DateType):
             return BoolType(self.value < other.value)
-        return NullType
+        return NullType()
 
     def __str__(self):
         return self.value.strftime('%Y-%m-%dT%H:%M:%S')