      if list
      then list
      [ elif list ; then list ] ...
      [ else list ]
      fi   The if list is executed, and, if it returns a zero
	   exit  status,  the  then list is executed.  Other-
	   wise, the elif list is executed and, if its  value
	   is  zero, the then list is executed.  If each elif
	   list returns nonzero, the else list is executed.

      if ( list ) sublist
	   A short form of if.

      if ( list ) {
      list
      } elif ( list ) {
      list
      } ... else {
      list
      }    An alternate form of if.
