CINXE.COM

<!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: '92ea5205db181e93',cH: 'ay0Wk15xhvQE6qeNErUuyCRNFEkmqYM7G7ZIGyLCTrE-1744372793-1.2.1.1-yM.3Pu5sJUm9XMrE41NlXNSaEM9U_EanRQAr.QmyPkXyhlAD4rN2D2l34ejd8dV3',cUPMDTk: "\/1410.65395?__cf_chl_tk=lpLefWZQ3arDgHy0YuahcbgUyLLcNzo195yMAjWAPpQ-1744372793-1.0.1.1-OF5hL._r3lwC.XXG0YcG0urv_9rPJghD_6zl8zE2M8o",cFPWv: 'b',cITimeS: '1744372793',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/1410.65395?__cf_chl_f_tk=lpLefWZQ3arDgHy0YuahcbgUyLLcNzo195yMAjWAPpQ-1744372793-1.0.1.1-OF5hL._r3lwC.XXG0YcG0urv_9rPJghD_6zl8zE2M8o",md: "O47QAxOVQUxOjX1pK3QjqVhxf45Q2nRvAtArnYtvoDw-1744372793-1.2.1.1-Tev17pBAOdievs7PesRl0Hr_EWTySqhQ2eOp9A106uxZUPJs5f6e6zGfMujGmzimGTqt_bIz5irnqtUQqrRwY0GE8ND8u7xrfDHbk12CV7LoHZVjIQ7WAcmIqHTqPJnXBSnGfUUaKtThDK0MtKIq1j7cq1vai1umNBe82rJWnjvmwBWbhLLGcEeMjImC0bIHy2gmraZLqrB9WWUDMmUX6fj3fTIhye6W62NUNnfYyEyQNuiZ7J5EZ6xq.v3nEqA2btRFHoqjIzp2yoRA5zUwyi4jtC6mBmVhTRvZKlqZZUQMLW4Yi5Vnf8jy7HDqUFAyqjpsdpBbQ6WSMFxblnGV13WEozHwCvN0YSK0AyPBRcZ8nZd8r6XUHTGCXh5DajqKRh1uW.zZUQEXpOMXHmyuV1ispGxYIUaL1VVGodBmYPItkd7YwvDX2CWhRIaueSCjTJwDp067ztDq4bQn0f4mVpiHQpXWtW4oYMaxGoBm4O1uZU1XbvBh8HuGtwhB0YZv6txmTqc2_o_MjAtffN9kScRgNeqD9E2TmL900Vyxdz563nrtTMXpwWu141DjQBEvw9ZolOsefqr8YC7jauVJ8sG2j7A6p8sb00rcnLGGcH_lUl38St9sFCuF4YSM7PvvrNSHECpIzFHSZuf_cFYSI8pwPLYvHS3W6xBP3rtRm5_2NDpR3hIltZiXM3ydnI24Wcoz1SGqJcwUY.FYfH5HHjaiZ4diA.Aw619GIxt0Ce8O98daUx2Uw9wuP_DyqKpaqafCm_Hd8vduNcJ3n9D5jeNF1ruWz2G3lmQ2pwQ1BXIUZgH9k8n3pW2kRvVgJGwV6XdQB.ChX6rL27YSUAbPi19P2ZTbe43irx5HRJD3VR5ovNVa0jFhmX_KczuM7_mO9TJxGeO9GhsRnRVqV3ZxlF.ik6Rp4Xy3OVmZ3Pyf3GmomASxKlVkPlF_CwsBDv3YgXf.uL0LMDJeWAmnpbF16gu6nIyxuXdjo1ChuSJgsCkjb7bX37y6XIAVghqzbYzugN27X_6VaSjZ6o_4SewKEM9g4tECteDxjdds2Ekx8BQGvzBkZY_SdrmdFbIxG1DQtSx77fdKx0wtrjFnKE0eNCQW4fO480Kkq_cqFP0ciRYdcZeSEPvWOWHs0B5ELOMFM57fQGr5Mbf.FHnNSmTpI3Rpd5WZEkzy5LjnQBwpgGekYVuLHWM9mC9nMg4Dd7Eu",mdrd: "iKN6nqzhO.ohqDPvDLWzwtqwn5LdQem._DL0VnP1VBw-1744372793-1.2.1.1-cxr7.hv1oVzQSvOCxfUdeWctvhNeZUhPYL4SGWFJ4M2JS2bv_rHKwR3N0rJGXEieTuT03ROvoD3IixttYv7tc4pdtkq9RmLmtuYQmbMlasvfxuzvcHQ45_VcB.DjzTIJ3dzZ95nyvPMpG7ND9aRMBExNMxtn_Fq2h7zfhOm2AwA3Kf_ZbRILO2ix9FmAOFNHbFE_LJ_GtBjQQPteTDfgmGqePFTDzOInhWKrPrNJk1sZmivscYcjmROcXrUoAng0Fmp1.K33usUrKuRkwssITg1Dou0e1z1z3wI0PD0T4BW.QMKqeJt9yBzHa2Qh7DFTnncYoJgR4FB1NJsVr8cEpLiTR_RXie.WFRpb3zZ7I0xUrF9NpMyoh81KRmxTEExxCJdhmwhsbrvui.BAvWbXD7Es27aid7aqKHTUyFxlvpMppmIvZUT9PoMTROLoKKkFgWK6a9n6PN_CB8m29Zebi6MkoW1yA5pk4IJEAELesLNCxH1A7Zzhi3cP6gKLlYmM2ekDj61tXCqkxrqC4PRaqy8zu1SdOMOlNS0_oUdXSbMqYAMwmAQ7IPT6YJnFrrrivtZiIAUOvjJTgwG.tYqjXIdmMmcpe39WiD9LQyt3wQIC7dZyRBlsWP3ika_BQN8OBe8HmL6T1Ax6OZ83jyQn_z9qFbq.bWNc5sfIMMh9nrzjdHcrIDRPrV8fMNGNRPKdGbuoP3zt6Jb3y54.ZXGgFaNtoZDqMOqWWmqgeK_mU6bRVGF8wamacYLPDxrJkvsduYId288TIJ6o8IRUdR3NbBcRK5h6fDWDIlp6nkIjNvVVKpZunmkL1V84sDk2VpCXzvGMIpX3D_hGq08bEqHQC4IM.7VQ5MLWol.Oh2d.x3wJadOX70mMah.rJ73AOqL_b65EYbM8nRhCbSS5E97rEIYC1eug66kKsQ2ht5q4_jfJ09COobgcioUCq0gYaRAmGHYmckk5EmlTwc_LyHDioJI6FQkgtYl1tJzTjlw8ElrN3fTHfnaq7MAj2qRKO7gqwj0sMndCmzbGKWjZ54Sc5fLOK1dlee36l5_ha43zpjgRzUqYjRbIfgoszCuN1q.oToDTZPNs4RrYer2mNoPga4zkkOlnZcQQJGTS_gw1ZSr4X2wuB.6pR4PBadPwEcVVIWhlPpXdnReYpo8NCcK1v0a4HDdRAyhgQMJ8EkOFQc23vbtPShzJYExaY8H6b8V_6KfbSZMK4CI3EtQ5FCBRIwFWBilLI2nA_7cSDQorABCirAWClho4Tod1jLPZe0vadp9pPJJ6Mz2QQUboMQqGG0NSLySSKnGxIstAoSoF8vRJEozGsIjaJpCLj.3YxCClAwxJiG5tuadtr5SxaYB1o8YIGNYy4MpNMLmeoTXWZWkXdieyi9GWqJNO8.Akn0MfuIZgIUxWGmI8Prli8EkDRl6m6pSp9ln_Bp3ZybUThvMhXQp02fNMmslYn0TGPXiCYUMraN7kmWhqLHeG.kY4fE5siFfXBzLOi7fdLUTSnIMGXEcX5y.fX_52OKfN9TIOHQJnLrw.6i9BM9Z0.24kSo8KyjDIzM8s7HEEB8_Z6VD_H94nrlwIu8eGqB72uI5NtBlXMp6AS7Td1z2a0SyI4.IVGfQ8bK3tHlbPAjm7JtspDLiW6uJMGj5HjjGMd2zA5N9pdr5rAv2iAUZXj5VtfhUmeMuV4yiYhM_o14I.xrIEmNNCuHvtYyatREiFCyEPJsmWaIHS8mm8P0.EcqC4CvIKxyj0_ZTiSZHDrkZy1QLXroMr2bfqfZjLZ5mJd1NqV5Bo.pVLeXiRXMpkwK6lQrJ7osqk0xAKlJEAv45R4pQGsgEAl_Ao51SAFk1fkwlbThbmbTkbiiwL1Roz0xpeNlIzIONl4OGTmweKkEwMXfSMInZBVNYyPEpHHz6hsZzLOafWZUn.yHLM3o.zS8FLWMQm6LMKKR25lhRIV8i4k_BrDgmMKADaar_pkvIJ5BBv8dRYU2aXz1IM7mVcVMRi2DswgNHl8rH3BxRHUJDpO8MkKueAbV.raZT_LdoDnCFH7WttZOkwRZ2yfncQFKER3hN8rYOEsK1_JUWNaGrJJkQ"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=92ea5205db181e93';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, "\/1410.65395?__cf_chl_rt_tk=lpLefWZQ3arDgHy0YuahcbgUyLLcNzo195yMAjWAPpQ-1744372793-1.0.1.1-OF5hL._r3lwC.XXG0YcG0urv_9rPJghD_6zl8zE2M8o" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>