{+++++++++++++++++++++++++++++++++++++++++++++++++}
{+						 +}
{+	 STANDARD LIBRARY UTILITY FUNCTIONS	 +}
{+						 +}
{+++++++++++++++++++++++++++++++++++++++++++++++++}


function isalpha(ch: char): boolean;
begin
  isalpha := ( ('A'<=ch) and (ch<='Z') ) or
	    ( ('a'<=ch) and (ch<='z') );
end;


function isupper(ch: char): boolean;
begin
  isupper := ( ('A'<=ch) and (ch<='Z') );
end;


function islower(ch: char): boolean;
begin
  islower := (('a'<=ch) and (ch<='z'));
end;


function isdigit(ch: char): boolean;
begin
  isdigit := (('0'<=ch) and (ch<='9'));
end;


function isspace(ch: char): boolean;
{ returns true if char is a space or a tab char }
begin
  isspace := ( (ch=' ') or (ch=CHR(9)) );
end;


function toupper(ch: char): char;
begin
  if  (('a'<=ch) and (ch<='z')) then
    toupper := chr(ord(ch)-32)
  else
    toupper := ch;
end;


function tolower(ch: char): char;
begin
  if ( ('A'<=ch) and (ch<='Z') ) then
    tolower := chr(ord(ch)+32)
  else
    tolower := ch;
end;


r): char;
begin
  if ( ('A'<=ch) and (ch<='Z') ) then
    tolower := chr(ord(ch)+32)
  else