1 '\" te
   2 .\" Copyright (c) 2001, the Institute of Electrical and Electronics Engineers, Inc. and The Open Group. All Rights Reserved.
   3 .\" Portions Copyright (c) 2006, Sun Microsystems, Inc. All Rights Reserved.
   4 .\" Sun Microsystems, Inc. gratefully acknowledges The Open Group for permission to reproduce portions of its copyrighted documentation. Original documentation from The Open Group can be obtained online at 
   5 .\" http://www.opengroup.org/bookstore/.
   6 .\" The Institute of Electrical and Electronics Engineers and The Open Group, have given us permission to reprint portions of their documentation. In the following statement, the phrase "this text" refers to portions of the system documentation. Portions of this text are reprinted and reproduced in electronic form in the Sun OS Reference Manual, from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between these versions and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html.
   7 .\"  This notice shall appear on any product containing this material.
   8 .\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
   9 .\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.  See the License for the specific language governing permissions and limitations under the License.
  10 .\" When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE.  If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
  11 .TH isless 3M "12 Jul 2006" "SunOS 5.11" "Mathematical Library Functions"
  12 .SH NAME
  13 isless \- test if x is less than y
  14 .SH SYNOPSIS
  15 .LP
  16 .nf
  17 c99 [ \fIflag\fR... ] \fIfile\fR... \fB-lm\fR [ \fIlibrary\fR... ]
  18 #include <math.h>
  19 
  20 \fBint\fR \fBisless\fR(\fBreal-floating\fR \fIx\fR, \fBreal-floating\fR \fIy\fR);
  21 .fi
  22 
  23 .SH DESCRIPTION
  24 .sp
  25 .LP
  26 The \fBisless()\fR macro determines whether its first argument is less than its
  27 second argument.  The value of \fBisless\fR(\fIx\fR, \fIy\fR) is equal to
  28 (\fIx\fR) < (\fIy\fR); however, unlike (\fIx\fR) < (\fIy\fR),
  29 \fBisless\fR(\fIx\fR, \fIy\fR) does not raise the invalid floating-point
  30 exception when \fIx\fR and \fIy\fR are unordered.
  31 .SH RETURN VALUES
  32 .sp
  33 .LP
  34 Upon successful completion, the \fBisless()\fR macro returns the value of
  35 (\fIx\fR) < (\fIy\fR).
  36 .sp
  37 .LP
  38 If \fIx\fR or \fIy\fR is NaN, 0 is returned.
  39 .SH ERRORS
  40 .sp
  41 .LP
  42 No errors are defined.
  43 .SH USAGE
  44 .sp
  45 .LP
  46 The relational and equality operators support the usual mathematical
  47 relationships between numeric values. For any ordered pair of numeric values,
  48 exactly one of the relationships (less, greater, and equal) is true. Relational
  49 operators can raise the invalid floating-point exception when argument values
  50 are NaNs. For a NaN and a numeric value, or for two NaNs, just the unordered
  51 relationship is true. This macro is a quiet (non-floating-point exception
  52 raising) version of a relational operator. It facilitates writing efficient
  53 code that accounts for quiet NaNs without suffering the invalid floating-point
  54 exception. In the \fBSYNOPSIS\fR section, \fBreal-floating\fR indicates that
  55 the argument is an expression of \fBreal-floating\fR type.
  56 .SH ATTRIBUTES
  57 .sp
  58 .LP
  59 See \fBattributes\fR(5) for descriptions of the following attributes:
  60 .sp
  61 
  62 .sp
  63 .TS
  64 tab() box;
  65 cw(2.75i) |cw(2.75i) 
  66 lw(2.75i) |lw(2.75i) 
  67 .
  68 ATTRIBUTE TYPEATTRIBUTE VALUE
  69 _
  70 Interface StabilityStandard
  71 _
  72 MT-LevelMT-Safe
  73 .TE
  74 
  75 .SH SEE ALSO
  76 .sp
  77 .LP
  78 \fBisgreater\fR(3M), \fBisgreaterequal\fR(3M), \fBislessequal\fR(3M),
  79 \fBislessgreater\fR(3M), \fBisunordered\fR(3M), \fBmath.h\fR(3HEAD),
  80 \fBattributes\fR(5), \fBstandards\fR(5)