<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><br id="lineBreakAtBeginningOfMessage"><div><br><blockquote type="cite"><div>On Sep 11, 2025, at 7:59 PM, Fred J. Tydeman <tydeman@tybor.com> wrote:</div><br class="Apple-interchange-newline"><div><div>C23: G.6.3.5 The csinh functions has these two requirements:<br><br>- csinh(+0 + iNaN) returns ±0 + iNaN (where the sign of the real part of the result is unspeci-<br>fied).<br><br>- csinh(NaN + i0) returns NaN + i0.<br><br>Since csinh( x + I*y ) == sinh(x)*cos(y) + I*cosh(x)*sin(y)<br></div></div></blockquote><div><br></div></div><div><blockquote type="cite"><div><div><br>It seems to me that the last case should be:<br><br>- csinh(NaN + i0) returns NaN +/- i0<br>(where the sign of the imaginary part of the result is unspeci-<br>fied).</div></div></blockquote><div><br></div><div>For the csinh(NaN + <i>i</i> 0) case, cosh(x) is positive for any numerical value of x and the imaginary part cosh(x)*sin(+0) is +0 for any finite value of x. </div><div><br></div><div>The current specification is consistent with viewing csinh(x + <i>i</i> 0) as a function mapping the edge of the upper half plane to itself. And it avoids an unspecified sign. </div><div><br></div><div>This is unlike the case for csinh(+0 + <i>i</i> NaN), because the real part sinh(+0)*cos(y) varies between +0 and -0 for finite y.</div><div><br></div><div>- Jim Thomas</div><div><br></div><div><blockquote type="cite"><div></div></blockquote></div><blockquote type="cite"><div><div><br><br>---<br>Fred J. Tydeman Tydeman Consulting<br>tydeman@tybor.com Testing, numerics, programming<br>+1 (702) 608-6093 Vice-chair of INCITS/C (ANSI "C")<br>Sample C17+FPCE tests: http://www.tybor.com<br>Savers sleep well, investors eat well, spenders work forever.<br><br>_______________________________________________<br>cfp-interest mailing list<br>cfp-interest@oakapple.net<br>http://mailman.oakapple.net/mailman/listinfo/cfp-interest<br></div></div></blockquote></div><br></body></html>