Path: utzoo!attcan!uunet!mcvax!dik
From: dik@cwi.nl (Dik T. Winter)
Newsgroups: comp.lang.fortran
Subject: Re: CDC FORTRAN trivia questions
Keywords: arithmetic if logical
Message-ID: <7691@boring.cwi.nl>
Date: 1 Nov 88 02:29:16 GMT
References: <1196@helios.ee.lbl.gov> <3616@s.cc.purdue.edu>
Organization: CWI, Amsterdam
Lines: 15

In article <3616@s.cc.purdue.edu> ags@s.cc.purdue.edu.UUCP (Dave Seaman) writes:
 > In article <1196@helios.ee.lbl.gov> mike@quench.lbl.gov (Michael Helm) writes:
 > 	[Re:  Ancient CDC Fortran and the two-branch logical IF]
 > 
 >                                          but if I remember correctly, the
 > usual convention was to represent .TRUE. as -1 and .FALSE. as zero.  Some
 > of the very old CDC compilers used a different convention.
 > -- 
Beware, .FALSE. is +0;  truth values returned by expressions could have any
arithmetic value with negative for .TRUE. and positive for .FALSE..
So -0 is .TRUE. (yes, it is a 1-s complement machine).
-- 
dik t. winter, cwi, amsterdam, nederland
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