Path: utzoo!mnetor!uunet!husc6!sri-unix!quintus!ok
From: ok@quintus.UUCP (Richard A. O'Keefe)
Newsgroups: comp.lang.c
Subject: Re: min and max
Message-ID: <549@cresswell.quintus.UUCP>
Date: 19 Jan 88 23:29:31 GMT
References: <11182@brl-adm.ARPA> <2197@haddock.ISC.COM> <515@viper.Lynx.MN.Org>
Organization: Quintus Computer Systems, Mountain View, CA
Lines: 30
Summary: precedence of /\ and \/

In article <515@viper.Lynx.MN.Org>, john@viper.Lynx.MN.Org (John Stanley) writes:
> In article <2254@haddock.ISC.COM> karl@haddock.ima.isc.com (Karl Heuer) writes:
>  >What's the appropriate precedence for these operators?  (What was it on those
>  >compilers that had this extension?)
> 
>   The logical place for a min/max operator would be after <<  >>
> and just before the logical <, >, <=, >= operators.
> 
That's exactly where the compiler I used that had them put them.
And since /\ is like "and" and \/ is like "or", /\ binds more
tightly than \/.

Note that /\, \/, and - give you one of the more useful 3-valued logics.
{With << tighter-than /\ tighter-than \/ tighter-than <, - is already in
the right place for use as the denial operator in this logic.}
If you treat > 0 as true, < = as false, and = 0 as unknown,
#define THREEVALUED(x) ((!!(X)<<1)-1)

	/\  |   T    U    F	\/  |   T    U    F	-   |
	----|--------------	----+--------------	----+----
	T   |   T    U	  F	T   |   T    T    T	T   |   F
	U   |   U    U    F	U   |   T    U    U     U   |   U
	F   |   F    F    F	F   |   T    U    F     F   |   T

/\ and \/ are the standard mathematical symbols (albeit as single glyphs
rather than digraphs) for minimum and maximum.  On a related subject,
the DIS 8859/1 character set includes the times (x) and divide (-:-)
symbols as single characters.  Will it be legal for an otherwise ANSI
conforming C compiler to allow these as multiplication and division
operators?