The basic vocabulary of X-PLOR knows about numbers and character
strings. Note that the following definitions are special cases
of words.
complex:==( real , real)
is a complex number.
integer:==
is a positive or negative integer number, including
zero.
logical:==
is a logical variable, i.e., TRUE or FALSE. ON and
OFF can be used in place of TRUE and FALSE, respectively.
real:==
is a floating-point number.
string:==
is a sequence of characters enclosed in double
quotation marks.
Note that in instances where the sequence of characters uniquely defines
a word, the quotation marks can be left out. There are
exceptions to this rule in the
vector and evaluate statements; it is
recommended to use quotation marks with strings in
these statements.