diff --git a/examples/farrow-ubd-fiber.aps b/examples/farrow-ubd-fiber.aps
index 84bd278b..977af4d4 100644
--- a/examples/farrow-ubd-fiber.aps
+++ b/examples/farrow-ubd-fiber.aps
@@ -72,35 +72,19 @@ module FARROW_UBD_FIBER[T :: var FARROW_UBD_TREE[]] extends T begin
   end;
 
   match ?self:Operation=op_add() begin
-    if self.op_lval = IntegerLattice$bottom or self.op_rval = IntegerLattice$bottom then
-      self.op_val := IntegerLattice$bottom;
-    else
-      self.op_val := IntegerLattice$applyf2(Integer$plus, self.op_lval, self.op_rval);
-    endif;
+    self.op_val := IntegerLattice$applyf2(Integer$plus, self.op_lval, self.op_rval);
   end;
 
   match ?self:Operation=op_mul() begin
-    if self.op_lval = IntegerLattice$bottom or self.op_rval = IntegerLattice$bottom then
-      self.op_val := IntegerLattice$bottom;
-    else
-      self.op_val := IntegerLattice$applyf2(Integer$times, self.op_lval, self.op_rval);
-    endif;
+    self.op_val := IntegerLattice$applyf2(Integer$times, self.op_lval, self.op_rval);
   end;
 
   match ?self:Operation=op_sub() begin
-    if self.op_lval = IntegerLattice$bottom or self.op_rval = IntegerLattice$bottom then
-      self.op_val := IntegerLattice$bottom;
-    else
-      self.op_val := IntegerLattice$applyf2(Integer$minus, self.op_lval, self.op_rval);
-    endif;
+    self.op_val := IntegerLattice$applyf2(Integer$minus, self.op_lval, self.op_rval);
   end;
 
   match ?self:Operation=op_div() begin
-    if self.op_lval = IntegerLattice$bottom or self.op_rval = IntegerLattice$bottom then
-      self.op_val := IntegerLattice$bottom;
-    else
-      self.op_val := IntegerLattice$applyf2(Integer$divide, self.op_lval, self.op_rval);
-    endif;
+    self.op_val := IntegerLattice$applyf2(Integer$divide, self.op_lval, self.op_rval);
   end;
 
   match ?self:Expression=expr_apply(?e: Expression, ?op: Operation, ?t: Term) begin