Pascal Program toString not working - pascal

Question

I am working on a Pascal program that works with sets without using the built in operations. However my toString function is not working and I cannot figure out why.
This is the main part of the program
unit isetADT; {// do not change this!}
interface
const
MAX_SIZE = 100; {// if needed, use value 100; arbitrary}
type
iset = record {// your type definition goes here}
arrayint:array[1..MAX_SIZE] of integer;
setsize:integer;
end;
procedure makeEmpty(var s:iset);
function isEmpty(s:iset):boolean;
function isMember(n:integer; s:iset):boolean;
function equals(s1,s2:iset):boolean;
function card(s:iset):integer; {// cardinality}
procedure add(n:integer; var s:iset); {// does nothing if n is already a member of s}
procedure remove(n:integer; var s:iset); {// does nothing if n is not in s}
procedure union(s1,s2:iset; var res:iset);
procedure intersect(s1,s2:iset; var res:iset);
procedure diff(s1,s2:iset; var res:iset); {// s1 - s2}
function toString(s:iset):ansistring;
implementation
{// your implementation code goes here}
procedure makeEmpty(var s:iset);
begin
{s:=[]; clears array, unneeded}
s.setsize:=0;
end;
function isEmpty(s:iset):boolean;
var
empty:boolean;
begin
empty:=false;
if s.setsize=0 then
empty:=true;
isEmpty:=empty;
end;
function isMember(n:integer; s:iset):boolean;
var
count:integer;
begin
member:=false;
if s.setsize>0 then
begin
for count:=1 to s.setsize do
begin
if s.arrayint[count]=n then
isMember:=true;
end;
end;
end;
function equals(s1,s2:iset):boolean;
var
equal:boolean;
count:integer;
begin
equal:=false;
if s1.setsize<>s2.setsize then
else
begin
for count:=1 to s1.setsize do
begin
if isMember(s1.arrayint[count],s2) then
equal:=true
else
equal:=false;
end;
end;
equals:=equal;
end;
function card(s:iset):integer; {// cardinality}
var
cardinality:integer;
begin
cardinality:=s.setsize;
end;
procedure add(n:integer; var s:iset);
begin
if isMember(n,s) then
{it is already in the set nothing is done}
else
begin
s.setsize:=s.setsize+1; {adds 1 to the size so that the new member can be added}
s.arrayint[s.setsize]:=n; {puts member in the newly created space}
end;
end;
procedure remove(n:integer; var s:iset);
var
newsize:integer;
count:integer;
count2:integer;
begin
{needed to keep size constant when it is being changed in nested loops}
newsize:=s.setsize;
if isMember(n,s) then
begin
for count:= 1 to newsize do
begin
if s.arrayint[count]=n then
begin
for count2:=1 to newsize do
begin
s.arrayint[count]:=s.arrayint[count+1]; {replaces the removed member}
end;
s.setsize:=s.setsize-1;{removes unneeded size}
end;
end;
end;
end;
procedure union(s1,s2:iset; var res:iset);
var
count:integer;
count2:integer;
begin
makeEmpty(res);
if equals(s1,s2) then
{they are the same, nothing is done}
else
begin
{takes a member of s2 and puts it res if it is not in s1 since res is the same as s1}
for count:=1 to s1.setsize do
begin
add(s1.arrayint[count],res);
end;
for count2:=1 to s2.setsize do
begin
add(s2.arrayint[count2],res);
end;
end;
end;
procedure intersect(s1,s2:iset; var res:iset);
var
count:integer;
begin
if equals(s1,s2) then
res:=s1 {since they are the same only 1 needs to be returned}
else
begin
for count:=1 to s1.setsize do
begin
{number is added to res if it is in both s1 AND s2 only}
if isMember(s1.arrayint[count],s2) then
add(s1.arrayint[count],res)
end;
end;
end;
procedure diff(s1,s2:iset; var res:iset);
var
member:boolean;
count:integer;
count2:integer;
begin
member:=false;
if equals(s1,s2) then
{if they are the same then nothing is returned because there is no difference}
makeEmpty(res)
else
begin
for count:=1 to s1.setsize do
begin
for count2:=1 to s2.setsize do
begin
{if number is in s1 and not s2 then it is true and it is added to res}
if s1.arrayint[count]=s2.arrayint[count2] then
member:=true;
end;
if member=false then
add(s1.arrayint[count],res);
end;
end;
end;
function toString(s:iset):ansistring; {this is just a string with no size limit}
var
print:ansistring;
x:string;
i: Integer;
count:integer;
begin
print:='';
for count:=1 to s.setsize do
begin
i:=s.arrayint[count];
str(i,x);
print:=print+x+',';
end;
print:='{'+ print+'}';
toString:=print;
end;
end. {END OF PROGRAM}
and this is the runner for the program
program testisetSample;
uses isetADT;
var
s1,s2,s3 : iset;
i : integer;
begin
makeEmpty(s1); makeEmpty(s2);
for i := 1 to 5 do
add(i,s1);
for i := 3 to 8 do
add(i,s2);
intersect(s1,s2,s3);
writeln(toString(s3));
readln;
end.

Answer 1

Obvious mistake:
You are using
print:=print+'x'+',';
when you want
print:=print+x+',';
Mistakes in isMember:
member:=false;
you are not setting isMember, the returned value will be "random". You could remove member altogether and always use `isMember?
if s.setsize=0 then
Should be > 0. But it is not needed