CINXE.COM
Just a moment...
<!DOCTYPE html><html lang="en-US"><head><title>Just a moment...</title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=Edge"><meta name="robots" content="noindex,nofollow"><meta name="viewport" content="width=device-width,initial-scale=1"><style>*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;max-width:60rem;padding-left:1.5rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{font-size:1.5rem;font-weight:500;line-height:2.25rem}@media (width <= 720px){.h2{font-size:1.25rem;line-height:1.5rem}}#challenge-error-text{background-image:url(data:image/svg+xml;base64,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);background-repeat:no-repeat;background-size:contain;padding-left:34px}@media (prefers-color-scheme:dark){body{background-color:#222;color:#d9d9d9}}</style><meta http-equiv="refresh" content="390"></head><body class="no-js"><div class="main-wrapper" role="main"><div class="main-content"><noscript><div class="h2"><span id="challenge-error-text">Enable JavaScript and cookies to continue</span></div></noscript></div></div><script>(function(){window._cf_chl_opt={cvId: '3',cZone: "zbmath.org",cType: 'managed',cRay: '92d4b7d34a2440a6',cH: 'MRjsY5B7tNB4ibi96tKq3gnJevXQ5Di.fPjb3MMZWlQ-1744146276-1.2.1.1-jOy2OHyeFdTQ1kTH9cNIEGdkiJZsP52XgNK3eHz9yEledAGnyp5eUa5LLQyhUCiI',cUPMDTk: "\/1390.81489?__cf_chl_tk=Lst4Y92_.Wq0nY58nlMtEpgy0RiRPaUZQthKLKQBxNI-1744146276-1.0.1.1-Aqobizt2awa4B1OC4hZX31DQEYxxOkhTzYSq8BkqOBA",cFPWv: 'g',cITimeS: '1744146276',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/1390.81489?__cf_chl_f_tk=Lst4Y92_.Wq0nY58nlMtEpgy0RiRPaUZQthKLKQBxNI-1744146276-1.0.1.1-Aqobizt2awa4B1OC4hZX31DQEYxxOkhTzYSq8BkqOBA",md: "Rr3MJVPqlRIV83dlTIys0.Q4mzWJKGvx.HabcKQ9j04-1744146276-1.2.1.1-_3xcOFSDv3FST3cH2ZinuE8AmpNLhkiSEgPA4r2qCbOo6uaQcCWEiVj2i54XgiUvIi_uQVW1o37MKCbqHtRH9mJwpgaBkJnxsdQx2yeGvqPGO1wUMZYIJDthpkvL7Bk.XJPtoJPggB5t.sKbFxKymMSvPKFTo_AmzY4ETYB2z8QFwM9gFW35tcv1Fli7oMzbOhcj4XyEKfVEtVfgzwiaw5zTFbs7KOvVvMSiuIJbP6UOn6VtEwflpof6DyGa5HJi6FIukcSI6nSh3V.Yob4kJgWNaob3woxpTKf75EBtfrnPX3HJGaLU7OfBTim5mQx5jPHNpTAgURhH5MMdONjePwsZluDX19Xn1a2eEfMgTl26cr_TXafDv4odDGX3WgdiZ7FUor4pPEVAnCPW3YUV89agwi38INKpb.BivgkRoC0w.08kF4h6XI7vXiIGiUIfT.MhDl2pk5TIOSwB1jB9bkqD4fXMRkhiBdS_16Pr56Xy.I0zjQoLkdPE.NWACotwf_7NeuM7hNV1Bhnc9g_NSEbdxTMmXkZKwodwMzjwKOt0smMWDWRD4GrzM9NTrhegfBlrLjMEKJHpN1TGANJkVpjaEPMVQxDXqmv_o40ZDVwU835FEFlvc4QaGgwKJBP5Bn0yBO2DD7jAN1oN0LdElVQ8TPkSoCYEaj21DcZ5ZOu_9VBB42cZ_175OZ8DSiE5nG0uuM5lHFvTsORGSkyCAP_t_6U9C0ZTaTp1nxE8YGMp4hwxST8VYQjck21M1UpjkFENT1licnrNuir_cmosCC96XIoSdPyu.8p2MUsNeEPdlha93IqZdDd7t.Jvt9xo5NdWSxY3ZMxwwVbzcW2MRvBg.m2pc_qAP75WBLpyisJHHMfdJ9jwYZ4BZGgA70FQbtsgWSTTjBpG9EROBwK4tzO5u9w3FKWqE.2uI556V_70U7Gxv1L.Iq6sgW8G41pvZtdPYn02XgetrvJaQlFxujFO36hgAptFJVpn8isApDK7c0Xx3DQd5F2DNR4Ivx_E6jUgTOHS262yUhDJ4Hg2bFW5iHlEiPg9xhcYWQoA4iEgL4IINJnXtsftJ263xM_LS0RYn1sJdaRnLIXLhct0j_gEY9h03IH4K1anez3wv0m.8tlgvBb0YjvPaB_aE_poEUCmlniw1S1y3rJf6.eGzfL4gOp0XhsOVoMxpOrtHDM9..v_jc7mclTPq8IJM38y",mdrd: ".uQ5fEeXMtxLzQoIIA3Rnt2TopVhAOrIE71D0gsMBUU-1744146276-1.2.1.1-ov6kDMJhTCfGGZZ_9tTYmtcU4nm_O1aYgHbv_bxU6jOKQn7KkWttDUlXiG4eDi4nv3M7CUcejeIA4sjv.qqSvFRq2ekJRpWRryz2U8PJROiWDNgfZ9CG7xNrajl_AiBexjWoiqeilmYc2pjBpKeYl_Qm8xZaVZMKJyn0PFWCku.YX7P50cTlyrK.VX6D5XIccFTF70jntQkdIYc9ETCMwP6KV8AIUQGeuAgA0DxJyeWzyN3hBarq26V.hfXAnhVlDffkVMWxvkzI.xyDFkuuPu.q0cXg7OrdZeQJOPfoRUB6WgC95qjTJbtTXrj7pDDrOS8rltqn7ds7gWKT_DBuZ1h.Po4DYEL3cHjh5.uSE7bbq6tREm3knl7VJIPulIJ2318ZMYCP.XYPGTzORi.UAwPn6ccPcll7NsuxqKQ5jsgJiXo7IIVuR_0MJ.rt2MwpPwYIzTZfIEcaKyxsYa7WT7bS_wmIkjd7SrgKFUXbEVdnZkoEvmcj5_WtJsko3lYM9v8mTV7vFXI0J.HgtSY5BNG8DuHBnAqU2lbi.BtYnYqBKYJanctwzw6Ec95mzRnm7.SWzu8YE3AzRP2xhLggJXDaRUfyKEmFyxUpfIxU1tO9FlAl8QBPzFHPaRCqwkbz_d91eMbO15vWmjHfBz8zDsrBRxylYTUjhsq0nDUAe5eHsoYsij7zNrs8NxWenZC_kSLaaFZ.x3.PwjvK8hZxeTTkW8RSuoH3I7NuLudkfV9Tjn3jxvnILgEXDKKE6I0tRF2z.eca_GmpuphsuaL8eUPOcj5dItb8zSPGahIccmefyXdbm010M3k0J5pnAJ1mfo9VujcIfEP7QxFJKE81XRFg4JkgkJW1XWa6R3sVdQsk49GcFtEMjGVIwTf8YqJAH_StC5ovwZcw1FAvi_Qqk5WK38qZWNwxAeVzfGEJ4Tgg6q0fDu4fctj7xNtGzhklrnW.GJw.XfHyNiYrVMIC7BRJ1r1sG_M1WfRvl00uua9xR0XG4iF5cfeik1EhCck7LI9Ek3t8mqlPUe9xShvfSLJMIuEmdU111Vz_aK.TZh1kV.CsQeTYjBRX3LUAGIgjRbpjEDHeSYiyOd5PLbfCYNQ0XPy_W8Kp8Q4yYugc4i.thFiyDmtvkAIPbovgf8i_GLvzp8OLXliA6O5unbKACYw151lyQiv84tr1P.BNwrpxKUjNodfRF3sldJPLM_aqSU5i7O2X3ze6Nov.GTDajP0V6esk_PDKXrgOJVpy92RBG6a.BcUj7HEubtx9sPb1L0ejuS6X2P4LRITwOS0VAZh8HAlWq7th0wFo9dfXPFkzaaEwmlQME_PPYXr5ou7yD1snL7e_5WG7DGKlujKnQi.iWqNo4862ztEhU01pouTkf30qzIM7tDDAdz7STFQzadJHbjUclSMiP_DkAwtbnk3T5CTHLfPGNF1dhumijaqdzNYQLii6CfNQfTDwH9RZdaoJyS3PL.C6TwqHaSepSk1igGHBy7R1JFLKW0wpzN3kMf3GKRQ4nFLoOL45OB0pK1IBy0aIIVduoNTlVQc5oC6udOLX1zG4Lqg6gkB1YKmNjD.2qPY2hGNC9WDxl.CP.upk5FYtHTpbLPlRis6eBtiA5Cj4RNeM273CQxIoGG.5SjO21VpnBU17uj1s1F3FSfA_daoHwWo.PljICb1FQewYJ6IRw4HPTxwDe15sZQSNaK8TSsFZuvM0Jwqpx5i_b8faPYkT_ua3upEXgOwDfgmYbMLvZaTjL8CcuzaOiv4y3f_maBY7OoROiqzWkdpGe.Qq76ysKl54lUTVGhK2DibeixUwZhcOce.U7BaQip4P_SDlcrnt6DvQz7onEHm0vXnt8ZflVE6pOaxKKP.aosjLwN7wKg14O8a7X3TVegWEpr2h.u3Vwy3Rpv28gjcygtyJSRqHtfvquPCHBeEt_qlPk3n462.XKQOJ5bGXB.y3kXVQ9wrWnU0Fr9xNQHrEjxAjjKOFOhVNt_TSY3rv8htKuOUVvllYDm98yS.cJyc9S6atV0nNAQ8mesXefM6gGYTP86NK5xAWNQTIwml6lQ"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=92d4b7d34a2440a6';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null, "\/1390.81489?__cf_chl_rt_tk=Lst4Y92_.Wq0nY58nlMtEpgy0RiRPaUZQthKLKQBxNI-1744146276-1.0.1.1-Aqobizt2awa4B1OC4hZX31DQEYxxOkhTzYSq8BkqOBA" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>