Unsafe operations
As we have previously explained, the
operation Now we will show how this can lead to  not being actually closed due to anomalies.
We have to prove that 
 where 
 where 
.
The computation goes as follows. Consider the evaluation of 
 on a vector 
; the antifield expansion in the vicinity of 
 is:
Terms 
 of the higher order in 
 do not matter.
In passing from Line (44) to Line (45) we used the fact that 
 is non-anomalous, in other words
. In passing from Line  (45) to Line (46) we used that 
 is non-anomalous
in the sense that 
. The assumption that 
 is non-anomalous is quite reasonable, in fact
necessary for the consistency of the theory. But the ground for assuming 
is much less solid. One possibility is to require:
which is more or less equivalent to:
It is quite possible that there are other possible ways to make calculations
meaningful, without imposing the ugly constraint (47).