diff --git a/pisi/version.py b/pisi/version.py
new file mode 100644
index 00000000..b298859e
--- /dev/null
+++ b/pisi/version.py
@@ -0,0 +1,24 @@
+# version structure
+
+class Version:
+    def __init__(self, verstring):
+        self.comps = verstring.split('.-')
+
+    def pred(self,rhs,pred):
+        for i in range(0, len(comps)-1):
+            if pred(self.comps[i],rhs.comps[i]):
+                return True
+        else:
+            return False
+
+    def lt(self,rhs):
+        return self.pred(rhs, lambda x,y: x<y)
+
+    def le(self,rhs):
+        return self.pred(rhs, lambda x,y: x<=y)
+
+    def gt(self,rhs):
+        return self.pred(rhs, lambda x,y: x>y)
+
+    def ge(self,rhs):
+        return self.pred(rhs, lambda x,y: x>=y)