DB<1> sub tst  {return undef}
  
  DB<2> if ($a=tst()) {print "TRUE"} else {print "FALSE" }
FALSE
  DB<3> if (@a=tst()) {print "TRUE"} else {print "FALSE" }
TRUE
  DB<4> sub tst  { return (); }
  
  DB<5> if ($a=tst()) {print "TRUE"} else {print "FALSE" }
FALSE
  DB<6> if (@a=tst()) {print "TRUE"} else {print "FALSE" }
FALSE