diff --git a/src/contraction/contraction.cxx b/src/contraction/contraction.cxx
index 7af2a733..7f7f5b25 100644
--- a/src/contraction/contraction.cxx
+++ b/src/contraction/contraction.cxx
@@ -3413,7 +3413,7 @@ namespace CTF_int {
     mapping * map;
     spctr * hctr = NULL;
     spctr ** rec_ctr = NULL;
-    ASSERT(A->wrld == B->wrld && B->wrld == C->wrld);
+    ASSERT(A->wrld->cdt.cm == B->wrld->cdt.cm && B->wrld->cdt.cm == C->wrld->cdt.cm);
     World * wrld = A->wrld;
     CommData global_comm = wrld->cdt;
 
diff --git a/src/interface/set.h b/src/interface/set.h
index 8fedc609..460706fa 100644
--- a/src/interface/set.h
+++ b/src/interface/set.h
@@ -158,7 +158,7 @@ namespace CTF {
 
       Set() : CTF_int::algstrct(sizeof(dtype)){ 
         tmdtype = CTF_int::get_default_mdtype<dtype>(is_custom_mdtype);
-        abs = NULL;
+        set_abs_to_default();
       }
 
       void set_abs_to_default(){
diff --git a/src/summation/summation.cxx b/src/summation/summation.cxx
index 5094af77..c4033e87 100644
--- a/src/summation/summation.cxx
+++ b/src/summation/summation.cxx
@@ -1969,7 +1969,7 @@ namespace CTF_int {
     int btopo;
     int gtopo;
 
-    ASSERT(A->wrld == B->wrld);
+    ASSERT(A->wrld->cdt.cm == B->wrld->cdt.cm);
     World * wrld = A->wrld;
    
     TAU_FSTART(map_tensor_pair);