procedure merge ( a,b : RecordArray; var c : RecordArray; na,nb : integer );
{*** Merges the arrays a and b into c (increasing order assumed)
		a or b may coincide with c  ***}
begin
while (na>=1) or (nb>=1) do
	if na<1 then
		while nb>0 do begin
			c[nb] := b[nb];
			nb := nb-1
			end  {while}
	else if nb<1 then
		while na>0 do begin
			c[na] := a[na];
			na := na-1
			end  {while}
	else if a[na].k < b[nb].k then begin
		c[na+nb] := b[nb];
		nb := nb-1
		end  {if...then}
	else begin
		c[na+nb] := a[na];
		na := na-1
		end;  {else}
end;