diff --git a/temporal_networks/temporal_network.py b/temporal_networks/temporal_network.py
index 82cbbfd..ff23769 100644
--- a/temporal_networks/temporal_network.py
+++ b/temporal_networks/temporal_network.py
@@ -1,7 +1,6 @@
 #from msilib.schema import Error
 from queue import PriorityQueue
 import json
-from statistics import correlation
 from xmlrpc.client import Boolean
 import copy
 from math import inf
@@ -120,10 +119,18 @@ def sd(self):
     def lb(self):
         return self.duration_bound["lb"]
 
+    @lb.setter
+    def lb(self, x):
+        self.duration_bound["lb"] = x
+
     @property
     def ub(self):
         return self.duration_bound["ub"]
 
+    @ub.setter
+    def ub(self, x):
+        self.duration_bound["ub"] = x
+
 class Correlation:
     """
     Represents a correlation across a number of probabilistic "pstc" type constraints. Given n probabilistic constraints, such that for i = 1,2,...,n,
@@ -641,4 +648,4 @@ def __init__(self) -> None:
         self.correlations = []
     
     def add_correlation(self, constraints: list[Constraint]) -> None:
-        self.correlations.append(Correlation(constraints))
\ No newline at end of file
+        self.correlations.append(Correlation(constraints))