Как определить

program zadanie8;
type habitant=record
        surname:string;
        city:string;
        street:string;
        house:integer;
        addt:string;
end;
const habitant_n = 5;
const habitants:array[1..habitant_n] of habitant =
        (
        (surname:'Fadeev';city:'Moscow';street:'Podvorotnaya';house:1;addt:''),
        (surname:'Alekseev';city:'Kazan';street:'Samoletnaa';house:52;addt:''),
        (surname:'Marlin';city:'Habarovsk';street:'Pochtovaya';house:6;addt:''),
        (surname:'Popov';city:'Ufa';street:'Podvorotnaya';house:1;addt:''),
        (surname:'Pinkin';city:'Moscow';street:'Lomonosova';house:44;addt:'')
        );
var i,j:integer;
function is_one_address(var a,b:habitant):boolean;
begin
        is_one_address :=
               (a.street = b.street) and (a.house = b.house) and (a.addt = b.addt);
end;
begin
        write ('Живут по одному адресу,но в разных городах:   ');
        for i:=1 to habitant_n-1 do
                for j:=i+1 to habitant_n do
                        if is_one_address (habitants[i], habitants[j]) then
                        begin
                                write (habitants[i].surname, '   ', habitants[j].surname);
                                break;
                        end;
        writeln;
end.