Index: tol/btol/set_type/setgra.cpp
===================================================================
--- tol/btol/set_type/setgra.cpp	(revision fd9e44729e9f3913da990009391519fa663ed699)
+++ tol/btol/set_type/setgra.cpp	(revision 64f04d229d12c2fee3e28943c0a2f6118c8f04d1)
@@ -1883,6 +1883,10 @@
 //InitTotalTime("BSetFor::CalcContens");
   BStandardOperator* opr  = (BStandardOperator*)GetOperator(UCode(Arg(3)));
-  int from  = (int)Real(Arg(1));
-  int until = (int)Real(Arg(2));
+  BDat from_  = Dat(Arg(1));
+  BDat until_ = Dat(Arg(2));
+  if(from_.IsUnknown() || from_==BDat::NegInf()) { return; }
+  if(until_.IsUnknown() || until_==BDat::PosInf()) { return; }
+  int from  = (int)from_.Value();
+  int until = (int)until_.Value();
   BSyntaxObject* arg     = NIL;
   BSyntaxObject* objCode = NIL;