OpenEuphoria

Re: a.i

• Posted by Rom <kjehas at frisurf.no> Nov 23, 2002
• 2351 views

From: "Kat" <kat at kogeijin.com>

> .....
> Would the Ai know who these nicks are, normally, given only the
> intelligence i those lines? This is an example of why you haveto build =
in methods of
> determining data, what it means, and instanciating new methods to =
manipulate the  data.=20

> Some things no one can predict, and these events > raise errors at the =
worst times.=20

Very true.=20
If you mean that uninstanciated vars will raise logical errors ...  very =
true.

You are appraching what essensially is a design flaw in modern computer =
languages, including Euphoria. While it may be too late to do anything =
about the design flaws in C, it is maybe not too late to correct the =
design flaw i Euphoria. I am afraid this design flaw has to corrected =
before Euphoria can truely be usable for formulating logic.

The design flaw in Euphoria is the same as expressed in this pascal =
documentation:

"A Boolean variable can assume the ordinal values 0 and 1 only, but =
variables of type ByteBool, WordBool, and LongBool can assume other =
ordinal values. An expression of type ByteBool, WordBool, or LongBool is =
considered False when its ordinal value is zero, and True when its =
ordinal value is nonzero. Whenever a ByteBool, WordBool, or LongBool =
value is used in a context where a Boolean value is expected, the =
compiler will automatically generate code that converts any nonzero =
value to the value True."

This is NOT correct boolean logic. Neither Pascal nor Euphoria can =
handle uninstanciated  vars correctly.  "a > 1" is such a structure that =
implicitly uses a boolean var that cannot always be resolved, that means =
the value of the var is undecidable. Then the result is neither true not =
false! But Pascal and Euphoria will not catch that result.

So the control structure should have been like this:

    if a > 1 then ....    -- a > 1 is true
    ifnot then ....         -- a > 1 is false
    ifnil then ...           -- a > 1 is undecidable

The truth table is like this:

    (a > 1)      result
    true     ->    true
    false    ->    false
    a is uninstanciated    ->  nil

Rom