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: '92dd9b283b8744b8',cH: 'zHgMm6ORpSw5mKFfmRe_BImnM4v6VKPpyVbZxCNZXRQ-1744239473-1.2.1.1-50mcC7PmqlNn_mLVGgPebViOSeQiE2Hf3tk6Tb39EACO5pv_TiBDpMTCfso3oeE0',cUPMDTk: "\/1083.93047?__cf_chl_tk=mUPwR8S4AtycsWiJs4LOZ8PggISIffldrLDvDZCvp4g-1744239473-1.0.1.1-Iduew_DGNhBk6kCjuWauXO9Ku3dBnY8MfywiCLa1gkQ",cFPWv: 'b',cITimeS: '1744239473',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/1083.93047?__cf_chl_f_tk=mUPwR8S4AtycsWiJs4LOZ8PggISIffldrLDvDZCvp4g-1744239473-1.0.1.1-Iduew_DGNhBk6kCjuWauXO9Ku3dBnY8MfywiCLa1gkQ",md: "kQH_mTzGzRZPA7wpncXoU0h6LqC6vW9m.ExcFmabv0M-1744239473-1.2.1.1-mq2Z.OLcC7EMQ.sHIhP2U4Y3pdsXjiRAvWe5wYNEHhzIW5K9ueu_Bi2hSEG0UJSf3SIi7aSo7bgp9DdPdsGS2yO3Yf9szlJCLsVKhTdjspn8rlKtsiWJoZtu7lAHo31FpAm5YDTJd8LoTGP3_A2UTIxdD.2mJqYu6EeFHWPkT1P9w6nMRTErTO.iSGba1URwoRgVf8jXDh8FfukoUpUgq8OtFQQDZGHc3wxkf283BzTfJE95tBBgXVsCNNjxcsgboMTmjc3u3ePz2xKn9kJZkdv43eXD5NqaxtEkDzMh93aanP9XXelo6XCcq247p2Dr7ZCj0lnivoDlhoHoCigEI65FpB_TGWrox.F2Uun3G1S831i89tacbJimlRdtZQzTIMt7F0DHJSuA4cgj7YJbPtEIzoHgI3zaUmHR8Hm.8gKGtUVNmx27kXA30teYox30H3fgrjA1HTeX2EhvlX5aQ8yhENtzu.z85gQIOdkCdFygmdUeq8vL3AxANGAh3hfIMjVH6egZD2Wacu.wSUo4giJbHDfffeEIcDLhc77UIpiILOHkoFJAKy1cLvPwXo1zBtgwo39.xUQmIv5DSERywI9Y4aX_XLsqKV05nokeEXFlkM72.gZ4PNNx5Et6ogn.Kp3XbGeg_9cmZZzBdOlt2zchWfLqTbq4m5dAjFLF1._1ZC4A3dEg61Xhf8zau2JhLQV3iZsEjdPorny81UnW_Mi04IdxUNxrQk50WwltEqanxmrF_Rliy1ZbFb32j.hraIn_CiqcCJtFSVsivdQplyLMI5QfrKMy3uGKMdJ1n1ts9BOL_GGzvJy1CUb7cQmZw4UVF_frJEtrQI8fRra8MgrNFhzpar_uBOT5oGCFBB5VCA.mcIAZkw2TT4yWDMwGVO7BGtRJD.ESMoq7z5jL72ZoRElIyMvzrExn6F3JQD_Lk7O2z411PgNj3_.i5.u1ufKgwz2W.nslSoK4qitbAvSVw96IkF_.eotqLIM.TyUjVyGF_gJJvd9Atyk5BXOUZT_5N2Q5HI5E5IslWs1UEQDrnR7TYC6NtJfLTuVWlUgy.a0LORIbusxt8ze2ccaxcym2DGe5YNTxFUz_IgdW6jdGKz_Z9Rv1C9FAy2_JIa1H5bmzfdOaJxWz1L8OKBsQmrg61RDmIotKbNaxVlR78n2jkBOn05SKUrCW2ErR48o3qXeRMdQmjwacb3_mKoFc",mdrd: "r41dNjXKob2jtgRnuBnmoWN8UwjYdhHqwiKsoqcYcs4-1744239473-1.2.1.1-RdsXehSmXw5V5b4SPtWWZ1nJ89gOLIVExpSq1oRMWmV30m2D9vEKmPP4c12CV1.JAWhqR0TWA7P4o58rkq1c1PPzxzVsc4TWWSM.1TI1weBggirLfD3BP.dlnB8Y.pEqGWyFuE4CL9p3n__j5lVPh2qpTzSPMVY10ZexGie3uLsDW21A9X.kxgrpiU87LPIwb0D75YuD6dKWReE39v2ZbDOtZiXLBCc.1v78j7J7MLG2uXfpY2Z0BtWB2jOZ9fQu.g.y3oO6VeeDusuOKfBQ5XyffmeeNnPds61OSuoHcuAPPKn7_tLix9Mw8wwCgWUgG7.Kv8lQQ54duDVsfgVicNJbNzupHfrokzaCei9ERh5QNKeBXz0FJWAM5w48kDNFEZhZsD2aYwWRmIiBn9q05PuoPosCDODGGx9c0gJH8BZhgwoYlg5gSUiNeqL1ckf5CuUkuhFxxmKMdCdGIZTBLOpQN90WcODt5RhlZAkYMGdbwwXM76GC0nw4qmk_uYKuAQXwiLplg94ouN0tJZljAdCf2x4rypQ80xzgNixgWB8SSI50cFoJ1mqu1BsizUeKrWLBDdqnp3LWN8T50aG4sswojPVbunonR1.6Y0NY7gGrd9gd5q6gMW27uN42OTTE3gEeZ_dFoFnFaoyudndygkdGe_p4ZdTpJ6u88oTgpZFjvGrGF56rGZ5nilzSrMN9nsbAPM1fyFY4slneA5i_rOX27O2LfqEGxeY3OeCwoMjXA7AVrXAw8ZfI68IiokFawvmITaC8lBSTiu9wojZ9b76gQo..4O3vDUVt4W5ruGv8G0mWDs7y7_8s553MoUFX7lKKGZsoPE42jEyFluFR4vtbGE0Ac9_iPfyzu8nWWvKiYTpQIIL48cmRN9rkQm47H3lxJh_iQOCbhWJJmdB3gL92n3dJHYgHC3TgFiD7x2xw9nakbRXfNwvN_D0_Jh6ipEQiNArqOC0VHds6feGrjH3Q7yjA_mvPkrxl99S9MW4zpiNrC2aWuBRWreLuCt53eIRAL3gJR0XR6NQNK4ZFmWgi9hRbqfQNhn5ZMqA1zh4703WeICY773dMny6yCh1r4Gdy_9zHIFDXG4zrNt6Yu1GRSgn7_0OzFOwbMcGrzhDyEK2uwTpEycRenR3oGi_LuBkbqwDEQk16BmhrCG3LDUj0ax.V7oojMuXGChvDaz92oLGUGPDOxgAlh_3IQUhVohPRpmt9ZMIul0dqb.Udd1JO0JGJWH3wAkeJhGmjFg5nqPZ8kRMjqzYJLv4xU2yKJWchH8I3tY526JEFOBc0w33K0jubwFLF2gKvmaOzFLSOCVbKEOptOHG1FQ7XLoz5vlrdJAkP.8XhuBkb.4ntenpYNBFhMRCkM0GP_SQoyY1ybM58MPpHDxCSft6BtIJ4vra6PhrsjizYTGTvrcQ9vf5SGl2iYbKBJrB0z_T13ZozqRtB4ez7SO1.piEEIOIY5OH20ne7hCvSFz0tpMIwhrQ6cn8G9agq3yt3v14B9mT0IEeVeo.61s5Pc9F4KloD0RRhjoDLKo7KNSrLvZ8sogngQPr6nWxqXDOvBdNxjwE6IxCYAgh9cyZ8VRtXh9__7NTFrpRFFRvDCvnDKdN8.K9Sg7UhPup8vy9i52NQueOzyfHpqG4x4ETJoYG9maHZSmgOnoQVxB7EKb44bUmqxk0h1Ti1ie6A6UATI623aHLWIy2cQaNLKqJYWvin9xArvDSnFoh9GautjmMylf2x_PNEroOyErzpxxZv98AeKMQwtha51fcVoU550Lkwq0YxxVoLXUYmNfd9rWvFd0wbWNfCR7dq7EZKT0FXo5S1CkuN11HQXkCg._9pGrYzSWj5jgvUNeE.JTy5s4EkSHR7y9.RKV_fue3k3i7DKCElDJDsNZyi1u8AmUYecwunLzCp5ZcnJ.zZzW_29sA6gS5qwUxFIZla82fSXrdNylbeLzE1bm042Mq4a3iXf0E.pJXkNoceCxXw4xqoTGBlkPGOFv209luGTYoJzTiBdK.Y3XLo_czrsTKMWo9uUaqxwF3j"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=92dd9b283b8744b8';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, "\/1083.93047?__cf_chl_rt_tk=mUPwR8S4AtycsWiJs4LOZ8PggISIffldrLDvDZCvp4g-1744239473-1.0.1.1-Iduew_DGNhBk6kCjuWauXO9Ku3dBnY8MfywiCLa1gkQ" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>