# I want to make the control flow more natural here, if possible.
# I'd like to eliminate the flag variable.
# I'd like to eliminate the $tied variable.
# I'd prefer not to call any function more than once, if possible.
#
# I realize these goals may conflict.
# 
# There are four predicates:
#  magical
#  find_tied
#  find_regdata
#  var_exists
#
# Constraint: 
#  You may not call find_tied() or find_regdata() unless 
#    magical() has previously returned true.

if (magical()) {
  my $adj_negative = 1;
  my $tied = find_tied();
  if ($tied && var_exists()) {
    $adj_negative = 0;
  }
  if ($tied || find_regdata()) {
    if ($adj_negative) { adjust() }
    return TIEDSV;
  }
}

adjust();
...more code...