RE: [xml-dev] XML design of ((a and b) or c)

["Klotz, Leigh" <Leigh.Klotz@xerox.com>]

Yes, boolean logic is as old as the hills, but the question here is
whether the evaluation of AND and OR stopped once the value became
determined, or whether they evaluated all arguments.  If evaluation
stops, then AND and OR can be used as control constructs.

Leigh.

-----Original Message-----
From: Ken North [mailto:kennorth@sbcglobal.net] 
Sent: Thursday, December 14, 2006 1:34 PM
To: xml-dev@lists.xml.org
Subject: Re: [xml-dev] XML design of ((a and b) or c)

>> It's possible that Lisp in 1958 had the AND/OR feature; [4] is a good
>> read but doesn't give clear enough indication of Lisp prior to 1.5.
>>
>> Does anybody know of a language after Algol 58 and before Lisp 1.5
that
>> had this feature?

Keep in mind AND gates and OR gates were fundamental computer circuitry,
just
like adder circuits, timing circuits and registers. So there were
machine
language and assembly language programmers using AND and OR instructions
of
various flavors.

As for compiled languages, both FORTRAN and COBOL had keywords for AND
and OR
logic.

Grace Hopper developed FLOWMATIC for Univac in the 1950s, which fed into
the
COBOL standard. I don't know about FLOWMATIC, but COBOL had/has 'AND'
and 'OR'
keywords. Grace Hooper and the Univac I are shown in this 1952 photo at
the
Computer History timeline of software and languages:
http://www.computerhistory.org/timeline/?category=sl

Another language that emerged in the 1950s was FORTRAN. FORTRAN has
logical
statements with .AND. and .OR. logical operators, but I don't know
precisely
what year they became part of the language. My old FORTRAN reference
manual sits
in the Computer History Museum. It was FORTRAN IV (vintage 1964), when
FORTRAN
included .AND. and .OR. operators.

An earlier version (FORTRAN II) apparently didn't have .AND. and .OR.
This is an
IBM 704 FORTRAN reference manual from 1958:
http://www.bitsavers.org/pdf/ibm/704/C28-6000-2_704_FORTRANII.pdf

This photo of the IBM 709 computer is vintage 1957.
http://www-03.ibm.com/ibm/history/exhibits/mainframe/mainframe_2423PH709
.html

This reference manual for the IBM 709 explains the machine instruction
set,
including AND and OR instructions. It also includes an IBM 709 FORTRAN
reference.
http://www.bitsavers.org/pdf/ibm/709/709_RefMan_Fortran.pdf











======== Ken North ===========
www.WebServicesSummit.com
www.SQLSummit.com
www.GridSummit.com


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