RS1:=proc(Y,i) local lucy,newY,j,k:
 lucy:=RS11(Y[1],i):
 k:=nops(Y):
 newY:=Y:
 for j from 1 to k-1 while lucy[2]<>0 do:
	newY[j]:=lucy[1]:	
	lucy:=RS11(Y[j+1],lucy[2]):
 end:

 # handle last row separately
 if j = k then:
	newY[k]:=lucy[1]:
	newY:=[op(newY), [lucy[2]]]:
 fi:

 newY:
end: