- M pushes a symbol onto its store whenever the stock size of M'
increases, that is
if 
is in M'
It can be shown by induction s that L(M)=L(M')
Theorem : The language 
is not a DCFL.
Proof : Assume for contradiction that there is some DPDA 
accepting L. Without loss of generality we can assume that P is in standard form, i.e. every move of P is either of the form
or one of the forms
