Inc
From the Scripting Manual
procedure inc(var X: integer; N: integer); Parameter Info: variable X (Integer): Numeric variable to increase by N (see below) N (Integer): Number to increment X by. Description: This function will increment (increase) the value of an integer by whatever number you specify in the N field. See below for an example:
Examples
var
MyNumber: integer;
begin
MyNumber := 0;
WriteLn(inttostr(MyNumber)); // 0
inc(MyNumber,1);
WriteLn(inttostr(MyNumber)); // 1
inc(MyNumber,6);
WriteLn(inttostr(MyNumber)); // 7
inc(MyNumber,13);
WriteLn(inttostr(MyNumber)); // 20
end;