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: '92ea5312ebd5f838',cH: 'lEkRH9.xY5Ts9mE6sYtWTyfoylcjDzSV2_FFzcVhlpY-1744372836-1.2.1.1-M0hwl8AI17iD4.T4MGBX1QbzbAqhkj2eLp2.vEEvxH5HD77N8paQnibjri_Zhc1I',cUPMDTk: "\/1154.62323?__cf_chl_tk=4DuGWKbp3hXX1GmBQxqAJPBYSwSskzxdzAIkVoiu6BA-1744372836-1.0.1.1-RDAcsbeNotB.AGah9yYb6XPa85PCMby4ayPVpaInXkU",cFPWv: 'b',cITimeS: '1744372836',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/1154.62323?__cf_chl_f_tk=4DuGWKbp3hXX1GmBQxqAJPBYSwSskzxdzAIkVoiu6BA-1744372836-1.0.1.1-RDAcsbeNotB.AGah9yYb6XPa85PCMby4ayPVpaInXkU",md: "CoXZsUyTcH9Zo.fk7clV9TGukvekRmdSoJwKCOvYdEw-1744372836-1.2.1.1-0FfuXbpnxPzT2bbCtyHyvo._6B_9RBLDXingqG56aiyefYZ4yoIqNyO27WUkcqP5rLStUQzGDJ5VF_enO_4rNmMPk2sGFndzCoE4NREerph3WdYaZzUhiqpq38MiKiZmnluwt9NqxT3R7ynhn7TzQVZvxNpfBxafQj3snf7.JeIdJkVHpILkUs39wptghjKmADIR3FCu.av6f1p6nimg.pNoP4_0y.YGQ9S.TWnjJyW1COAZyS7gTBKM3xyeOpsilJsULiEXtRUolsEFgvB4eDIYiRXzFainkGo8pVJV7FZR8DUdKz5A5_Gbl2znydSFIJz4aQOmq_P14reVolVNDCrx7Bbzfao8KUs2.9EemUH8LPnDezAfQhBwS_NuQws.rbwhW60Zc1Q0qG4IIO8D5toThBWkh3SIev_OXbyax5MfXeguu04ICt1qUC9DXlkZlI8xsdggajA0lx3SRmupMdRzH1MCnI7KCBpRmiUsW9QewrwfiFnygoWSwBM_2wy6.hhZBN0xpZnma_23wf.OGhCY_f5IWK5bXx_uyUR4pnVQi2E2PfOlLd7iYfj.m8LNFzWeb7Nuiz2OnWNrf3SIza.wQWuUYvTSofdVrs.N.UigXhaWlOzXOuy2L3vCQFO9tuBMg6iwLOfa8Gme_2t5ZVuqgGpLEV2WbwP_9ar7GrVKum4VuIdNJ20jmO5SW.vkMCitW6tGl6hT1el3mD4rXl0fNRrn7kUv7d.kT.KZ4BzcX.7AwUmtAyq1wP8LQNHEZY2giBjPCtD2ofzT6VNBOZ5b_.PnovDia6JuSjSig9wBk2rVDdhcvjOr3b2dM3CbXUBQJ9VYF6.RAiz0BooE51WsLVlXUkZ0SoqDIMzRfNHa8I21KbPQoVrYvErFu1nIZVTCrXjiopD5u8tNX8DEKZ4VWKUashKB70fw4ha_FucDjV3hHUF2PqymI_eHXcBzC2k2rq8.X21e6otxprcuomDTbjr5ptouM_ZIc8keFsXmSJuV1AlwSdH.gnYkiwiXBMHpIoYwPTsiLnnAnlZoN8MSt1iMyLBkGo.GGf3TH1cgyrXgVsyi1a8i53zVaObZ7iXMgrYIKUBTAzqNsmXQTqhrmV5O2tA4uPjboZmo4KSim4GKsOkrgzmqT8CZsuM2lLp_MkITzceIvq_.3lnP9HT3skjpok_MTZOzAEsciNp.BOa6dSgYElbWFDZjCW0N",mdrd: "XohgWFVQ7.DHKtbxECgjxIBjwoOLCu4hUIuAM56qZcQ-1744372836-1.2.1.1-r41amqJLXqjq0COTWAHe1m3u._XUa2tZjhVMVfjv5haIVdv9d5YC4eag8h05xvH8kw9Rmbe5HmYkK1WJ2ChRXRFb9AcfhNaRqD.r2vGMuAPZcEfjpDLpQCiNb8571ZrPA7uV.nvCBP05IAie6pGVWIArMhYkHM87deFQxdaHbc5Mz8EtBxUtEoNmZvvFHDVH7fmi.FnJR9wvJfy8dJ1OayQqOh8UmkFm1Z.EMXNmF1wk5wWVowCnbxzyZ9ZGPCp_oX7jc3l1MvoU5wcjTDUu2l0qEMOx6H7vwZKnIO4Vrk6QCM5jlysqhGuLF.wLFDxw8aSoGhB.ybGOncREKBukcocHlYeAnqlwnTXBEF29yuca9JYgynzKJDYu7kS5LcAIyZhsAYWL7ZWzDu4pl8LqP1WLAi918DkU_odraMc.HdhgILkF.0OK3mRbmrpVXUxDYKJakg7VPmelTum42lcQ9HAvHAhH3LmpcYH.6t5rdlVQRAJSVFgk6KoeSqDUlRzIDAmIh0BR0VBN.1OqRkNSK23lIQDeQQCHlZIE6AaX_OSKoN8xJZ4o7x7Z95gS8PM7EABWZMM6mvRGLH9P3UswT2IYSSE3FJpG_wBgkzNM8NEowCS8iU9OxLBG_.7H3k7RXKoti6ofCaoeB_D.mp6wJGXoxBvtBsjt8umIVCqNsWHC_Zhw0r44Z2Miv6SsBJzA7TKPCAjQQg7WU16mASN1t.SVC.fYr6DpaEmQRH9FQDI6VYZsqMlghgOF82RmZFA0WY7sgBf07HoOk51YC0gtRXo1UwdhHFioQ0iZ4nV2hWQ14li7bcnUWIzzXuScJumJYQoToX0zR4ThalaZmSBsdASEeXXFS53SIoOW4h84faBgDyzqX9q2ClwKt_UALP9g5C3EQTfm8r.8TIjIMGGXy4VkNK0IhYvXfBoMPtOBn6LlinEW3g..apzZOti8qsXjz4rvY15qCwBnXpEeU_SeEvyHy8Z28FHL4se3V2MogeIynGvd8otpo_mLLqQ.dUw.u06wU7miAkTGdREj.JrWCK_GzHzV0TbT2aj_cO6RQhTtw6wKO8oT.LsAVZWrv12dPxXLez10sHqnAlqXphm3SbQPE79vX_USt8wQA2zo7DBwhtvGTTwus_7FMJE5ZrE8XUVW3NtVvDtikNS_Dk4J.EQDStNUCodiQrTT5k53UoUuCVXFwKcsygeYk_AvjhaXnX3a28lRInpE7RR_imxYjfKCJ9FobboaURfiMnZP1PkPHdBiT64RxiUmUT24dIj4AbjgQsKo4ORhbUw9IEUpTAkYTjuJuEjegpzlGJm1mSBEL706yhGeSi02DicsNdJdZdd1M0C8q8kX9n4dmb3OqFd7.BI.DQXCLzh6DI49OL3zt1LhEcjIxc75k8wexg5tV1Z84Of3x7WtmP9Lc5K8ki3yZzgSE.hMQNTg1kWhiqSeSQyf6RNQzy4djfDHj9hID.RbBdl_rYC5C4MCfQYoK7hUW1xIP9zpqv4JmYf.czdExK.T1u_5sAoj4YjM.CSghdsSqIjulOJYb45GVNxYaqvWyVJP632QQWpnEtjKK9sc.cK6wcY4hMOIBk35M4_Gaod28Dwa5dB1Vgxo_YbvyGIR4bG16il93qdQjIKQYP_ri9M.88hyp6_2ua6HKWjOQ3VXI1v80KyLY3THx4_7zPv2dTrXGrBzxg5gO9UqUsT1BFpbTTAPQIPYkuuAL7f9HMSwGpQsraF6UzCtyGYVCVGrCN3dmhIIpQul_xGX8lUCzn.jEQ.fQkeDff3.8ByvG1B8akQWPArAO_0T7p7qGQmQrrozM1Sndp8rZf8NrNrKHd.35_BhoI167en1XfK5isUm699Ko2C8Y.BF2ZG_VgDerUrxJ5oeGZyfW7JKJ40L6WZowkYt4Lmh1MV8KJpRdaIA5hPZmOasiTMP_zzQz4bmnRMP5MELZtRRvxzJ3BH65PiPsURLpRM7XfCb6MEb0217fbsAF5CiG56WjGdjJcvhNNZPZuC0yGzpPiTsQg58uFGvQNjN111C4RDRGOgUqp6E58Ogd_rrbhFCnYoIBg"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=92ea5312ebd5f838';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, "\/1154.62323?__cf_chl_rt_tk=4DuGWKbp3hXX1GmBQxqAJPBYSwSskzxdzAIkVoiu6BA-1744372836-1.0.1.1-RDAcsbeNotB.AGah9yYb6XPa85PCMby4ayPVpaInXkU" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>