184  Pascal Report  Parameters allow each activation of a procedure or function to operate  on entities (values, variables, procedures, functions) that are specified  11.3  Parameters  function  sqrt(X:  Real):  P '.31;  {  Newton's method}  var XO,  Xl:  Real;  begin  Xl  := X;  X  >  1,  Newt  :1' S  method}  repeat  XO  := Xl;  Xl:  (XO  +  X/XO)*O.5  until abs(X1  - XO)  <  Ep  *  Xl;  sqrt  := XO  end  {  sqrt  } ;  function Max(A:  Vector;  N:  Integer):  Real;  {Return the maximum value of elements  All], .. . ,AIN].}  var X:  Real;  I:  Intege  begin  X  := A[l];  for  I  := 2  to N do begi:  { X  =  Max ( A I 1],  ... ,  ,\  l  1-1)  )  }  if X  <  A[I)  then X  .- ~[I)  end;  { X  =  Max ( A I 1),  ... , A  :;  J  )  Max  := X  end  { Max  } ;  function GCD(M,  N:  Naturao):  Natural;  begin  if N  =  0  then GCD  :=  M ELse GCD  :=  GCD(N,  M mod N)  end;  function Power(X:  Real;  1:  Natural):  Real;  var W,  Z:  Real;  I:  Natlal;  begin  W  :=  X;  Z:=  1;  1:= 1·  while  I  >  0  do begin  {  (W  **  I)  if odd (I)  then Z  := Z .  W;  I  :  =  I  di  v  2;  W := sqr(W)  end;  { Z  =  X **  Y }  Power  := Z  end  {  Power  }  X **  y }  Example offunction declarations. 