Ошибка в программе "встречено '.', а ожидвлось "

Program Trapecii;
uses crt;
var n1,n2,n3,n4:int64; a1,a2,a3,a4,b1,b2,b3,b4,h1,h2,h3,h4,s1,s2,s3,s4,x1,x2,x3,x4:real;
function f1(x:real):real;
function f2(x:real):real;
function f3(x:real):real;
function f4(x:real):real;
begin 
f1:=(x*x+1)/((x*x*x+3*x+1)*(x*x*x+3*x+1));
f2:=(sin^(-1)(x))/(sqrt(1+x));
f3:=1/(x+1);
f4:=sin(x)/(5+3*sin(x));
end;
begin
clrScr;
writeln('Введите a1,b1,n1'); readln(A1,B1,N1);
writeln('Введите a2,b2,n2'); readln(A2,B2,N2);
writeln('Введите a3,b3,n3'); readln(A3,B3,N3);
writeln('Введите a4,b4,n4'); readln(A4,B4,N4);
h1:=(b1-a1)/n1;
x1:=a1;
s1:=2*f1(x);
h2:=(b2-a2)/n2;
x2:=a2;
s2:=2*f2(x);
h3:=(b3-a3)/n3;
x3:=a3;
s3:=2*f3(x);
h4:=(b4-a4)/n3;
x4:=a4;
s4:=2*f4(x);
for i1: integer :=1 to (n1-1) do 
begin 
x1:=x1+h1; 
s1:=s1+2*f1(x);
end;
for i2: integer :=1 to (n2-1) do 
begin 
x2:=x2+h2; 
s2:=s2+2*f2(x);
end;
for i3: integer :=1 to (n3-1) do 
begin 
x3:=x3+h3; 
s3:=s3+2*f3(x);
end;
for i4: integer :=1 to (n4-1) do 
begin 
x4:=x4+h4; 
s4:=s4+2*f4(x);
end;
s1:=h1/2*(s1+f1(b1));
s2:=h2/2*(s2+f2(b2));
s3:=h3/2*(s3+f3(b3));
s4:=h4/2*(s4+f4(b4));
writeln(a1,' ',b1,' ',n1,' ',s1:0:6);
writeln(a2,' ',b2,' ',n2,' ',s2:0:6);
writeln(a3,' ',b3,' ',n3,' ',s3:0:6);
writeln(a4,' ',b4,' ',n4,' ',s4:0:6);
readln;
end.

Program Trapecii;
uses crt;
var n,i:integer; a,b,h,s,x:real;
function f(x:real):real;
begin f:=(x-x*x*x)/(x*x*x*x+2) end;
begin
clrScr;
writeln('a,b,n'); readln(A,B,N);
h:=(b-a)/n;
x:=a;
s:=2*f(x);
for i:=1 to (n-1) do begin x:=x+h; s:=s+2*f(x); end;
s:=h/2*(s+f(b));
writeln(n,' ',s:0:6);
end.

type func=function(x:real):real;
function f1(x:real):real;
begin
f1:=(x*x+1)/((x*x*x+3*x+1)*(x*x*x+3*x+1));
end;
function f2(x:real):real;
begin
f2:=1/sin(x)/sqrt(1+x); //исправил Вашу функцию, не знаю верно ли, но sin^ такое не пишут
end;
function f3(x:real):real;
begin
f3:=1/(x+1);
end;
function f4(x:real):real;
begin
f4:=sin(x)/(5+3*sin(x));
end;
 
procedure trap(a,b,h:real;f:func;n:byte);
var s,k:real;
begin
s:=(f(a)+f(b))/2;
k:=a;
while k<=b do
 begin
  k:=k+h;
  s:=s+f(k);
 end;
s:=s*h;
writeln('a',n,'=',a:0:1,' b',n,'=',b:0:1,' h',n,'=',h:0:2,' S',n,'=',s:0:3);
end;
 
begin
trap(1,5,0.05,f1,1);
trap(1,5,0.05,f2,2);
trap(1,5,0.05,f3,3);
trap(1,5,0.05,f4,4);
end.