Date:         Thu, 6 Jun 2002 02:27:29 +0100
Reply-To:     John Whittington <John.W@MEDISCIENCE.CO.UK>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         John Whittington <John.W@MEDISCIENCE.CO.UK>
Subject:      Re: Missing = zero; Immediate If?
Comments: To: mark.k.moran@CENSUS.GOV
In-Reply-To:  <E17FeZO-0007Aq-00@relay1.netnames.net>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 13:27 05/06/02 -0400, Mark Moran wrote (in part):

>John,
>In logic, mathematics, and every field that depends on logic or math, the
>phrase "if A then B" means that "A implies B".

As will be apparent from my other messages, this is where I have caused
this discussion to 'go all wrong'!

I was not talking about 'logic, mathematics or every field that depends
upon logic or math' - but, rather about computer code - i.e. data
processing instructions.  As per Sig's comments, if you consider the simple
situation in which A is 'x=5' and B is 'x=6', then, in terms of PROGRAM
CODE, it clearly is not the case that "if A then B" means that "A implies
B".  It's just a set of processing instructions (and B need not even be one
which involves tests or manipulations of variable values - e.g. if A then
STOP;), not any attempt to indicate a logical implication.

I hope it's now clear why my comments created confusion - it seems as if I
was talking about something different from everyone else!

Kind Regards,


John

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