Langage pascal

procedure solv(a,b,c:real; var x1,x2:real)
var Delta:real;
begin
if a=0 then
if b=0 then
if c=0 then
writln("il y a une infinité de solution");
else
writln("pas de solution");
else
x1:=-c/b;
else
begin
Delta:=sqr(b)-4*a*c;
if delta<0 then
writeln("Pas de solution réelles");
else
begin
x1=(-b-sqrt(delta))/(2*a);
x2=(-b+sqrt(delta))/(2*a);
end;
end;
end;