gap> Y2:=FiltrationTerm(F,10);;                   
gap> for t in Reversed([1..9]) do
> Y2:=ContractedComplex(Y2,FiltrationTerm(F,t));
> od;
gap> Y2:=ContractedComplex(Y2);;

gap> Size(FiltrationTerm(F,10));
918881
gap> Size(Y2);                  
61618

gap> Y1:=PureComplexDifference(Y2,PureComplexRandomCell(Y2));;
gap> Y1:=ContractedComplex(Y1);;
gap> Size(Y1);
474
gap> Display(Y1);
