Empty arrays
============

Hendrik Boom wrote to me that the OS/360 ALGOLW compiler allowed
"empty arrays" to be declared, with the semantics defined below, and
that using them made some algorithms considerably clearer. Awe allows
them also, for the sake of backward compatibility.

**Definition**

Replace the last sentence of 5.2.2. *Array Declarations, Semantics* with this:

    In order to be valid, for every bound pair, the value of the upper
    bound may be no lower than one less than the upper bound.  If a valid
    array has any bound pair where the upper bound is one less than the
    lower bound then it is an empty array.

Replace the second sentence of 6.1.2. *Variables, Semantics* with this:

    An array designator is invalid if its array identifier denotes an
    empty array (Cf. 5.2.2) or if any of its subscripts lie outside
    the declared bounds for that subscript's position.
