# $formatThis is not known here

sub A {                     # begin of subroutine
    # what is $OBJ ? is it a global variable? or is it passed into this sub?                         
    # what is $p ?   is it a global variable? or is it passed into this sub?
    if ( exists $OBJ->{$p} ) {
        my $q = $OBJ->{$p};
        $q = &$<package_name>::formatThis($q); # wrong! <package_name> means:
                               # read one record from filehandle 'package_name'
        print FH "$p=$q ";
    }

  my $formatThis = sub {    # $formatThis declared as my(), lexically scoped
    my $x = @_;             # wrong! evaluates @_ in scalar context!
      my $y = sprintf ( "%.2f", $x);
      return $y;
  };
}                           # end of subroutine

# from here on $formatThis is not known