Во всех программах одна и та же ошибка 113, почему?

Program PR1;
uses crt;
Var
a,x,b,z:integer;
y:real;
begin;
clrscr;
write('a=');
read(a);
write('x=');
read(x);
write('b=');
read(b);
write('z=');
read(z);
while(x<=3)and(x>=-3)do;
begin;
if(a<>-b) then;
begin;
if(x<>0)then;
begin;
if(x<>-2)then;
begin;
y:=1/(a+b)+1/x+1/(z+2);
write('y=',y:5:2);
end;
else;
writeln (‘н.р');
End
else;
writeln (‘н.р');
end
else;
writeln (‘н.р');
x:=x+1;
end;
end.

program pr2;
uses crt;
var
b,x:integer;
y,a:real;
begin;
clrscr;
write('b=');
read(b);
write('x=');
read(x);
while(x<=2)and(x>=-3)do;
begin;
if(x<>-3)then;
begin;
a:=1/x+3;
begin;
if(a<>-b)then;
y:=1/a+b;
writeln('y=',y:5:3);
end;
else;
writeln('*.а');
end
else;
writeln('*.а');
x:=x+1;
end
end.

program pr4;
var
a,x,z:integer;
y:real;
begin;
write('a=');
read(a);
write('x=');
read(x);
write('z=');
read(z);
repeat;
if(x<>-2)then;
begin;
if(x<>-3)then;
begin;
if(z<>-2)then;
begin;
y:=1/a+2+1/x+3+1/z+2;
writeln('y=',y:5:4);
end
else;
writeln('*.а');
end
else;
writeln(*.а');
x:=x+1;
while(x<-2)or(x>2);
end.

одна и та же ошибка 113