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: '92d99a1edbb64a6b',cH: 'OxWm9UPLCJV8uBGCLIhIqYHiBKEQJ2q_j9wnMJwraV8-1744197488-1.2.1.1-GSKpnWRD_xbDwrhpBJyDS99IzmNwHQUFP_gjHZh5ih6l.6zzBj17rPJC426N5kjQ',cUPMDTk: "\/?q=in%3A365405&__cf_chl_tk=MOGxyiKQqTgyKRIqTQzn5N9uuHNUKeoV1.wFkM2qeP4-1744197488-1.0.1.1-ESMw7EID3CQZe7LFir65FYr8Gb.4JewZZ1Yp6q5sIKk",cFPWv: 'g',cITimeS: '1744197488',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/?q=in%3A365405&__cf_chl_f_tk=MOGxyiKQqTgyKRIqTQzn5N9uuHNUKeoV1.wFkM2qeP4-1744197488-1.0.1.1-ESMw7EID3CQZe7LFir65FYr8Gb.4JewZZ1Yp6q5sIKk",md: "uccLf6C4JOal62AuziED1F85zv3m1bHNZPKZxSEfex8-1744197488-1.2.1.1-.vpt13ziLhW0qfhUaXY4ATVUV6LRzxpGjzgHlZJxiuI9rfqnBhbI7wxsjdykjRddKgHlw6XmjXf0yy0446QrGBKPElfPxd6Ma0wQiPedwIGFUOkZbGJNWTdl8YEHmYX3atxf5UydPl2yPEjjL2oQTkgXNlDYI1WrWg3GgnfJ97bgW32oe6galqtaLiJiXEyM1BznZlcdYb29P.5fs0b.HuDEuoXSRJR9EzUe7bLPmtw92gnMUHcZUvhs5LNzPYlEwrLPmYlbOTDKYnXkERQMayabhjW7a64EhE_gpxdQVvivxG5soWR28kscRh5Ca_0C.Czt9BFpengIXmg9v7EpydZUfDNyaeVrX3_E0q0rEdBgSPqMed5dTOgsM_B5p0LGDWCTmqp_Zdk3bwVg0Zxbu5v4Ma63OrF3ajJfs.VQ0v9UWu7XvqkQ1ozQVAX_NozR9OSrRO0VEoTqTmzV18Y65sbjmfk283K9sVyZ705DovDu0OQ2y5vugdmag4QFySgSg9XDFMZW6wM0rhnJBKLnibjiFkolwEh4VQCqYWQ0wL5hsRos6sEAhKXjlx7HdGnxOkvWx9kowz2fdjJwWBfiLHc6Xnhuh4SmIz6px7Bzsto7NTWei_ZL7QWFPAp6Eha78eD6G65Bh2iLtjOGygefjF2A8vCAxSRVpa1YLc2ijXwPoeWDwZdOQXFRN_aZAjRGwm8gzLlKLTI2AYHivpJzDsgAoMzA.KYOGcHUO_7cbktfrwhcIb1jb4GTSOGjOpHqH3Yx4Q6qZnaFLsKf2H1U5B9vOSwNosDPGWyoBriRPfkOgFCBrE0dcVUzc3hLQGTFxrqrgwKLLQMRr9TbpIHHqqDXMaPMjgCQaZ8k1VyOQA8oqRxNXP8t8sRI8YAD1_jJoSY529aUXhm4AYiFpaU0giH4igBeYlNh3PXCQKlSiC5L81ZiO..7XdciZFa2GaOZqdeNv81jNXaEcg0N8LcTXQpb34baABVIzhvsFvTPJd2zeoLs7YlMlXF8a5_jG9fo4DlVloxn2cZ_Pyt6Glsb3gNnfnRj.1jzmaNCzzCMAikvuCFogzaPUlmUNbdXg64DE9io_ohMfKQT1QfTdQW2Gm3j5tQ1IEGar6oBDQHeFnrvF6SBakcZMxDP03dUWVSxNDc_745PLfE_IkTsh03hvCYoFn5F2DAKJtABQ_lkPrA8tdMVnOijd1UnW_aRpmgO",mdrd: "rarJQVhG7USSb1MbH99FT7TDXjZdFWqf427hGPv26FU-1744197488-1.2.1.1-ifr3cMNp8NR_19zBg6Xtd5PKDJ_c2_Ftxd6RayBvGQcJ3PIdN49ZlCkwdOgDXv9S9pK9m_an.KQMSsZ6ye14qK5ynZQYEUzoq78ysETxrrqhB1cagVo00o1pSTkRuYuFg0akXgflom8XbsikKhdyJysNMjJREimn7C_FIVgugcFeLPVHVIJtri0crkpKKCyC3PvS.UDbwMyrXd6XLYUiIY0xz6D3f06O.NG6WyXovodoM1edykLVzhPc6ZNft3cNiRbSB2cSFYgD7YRzhNxwNC1LNvx1WNNJ4mJiMX874oZlp8jyKh1B2JZqhIDC8ekIIAZHbeHJX83C1Y8pLDA_ncv7E8AfT1KY8NMb0boXGF7aRo_.TC.48WhdNG7CpdW1e1fSiVav4w7FdUI.2dyIppNlvdCQZR1a5kRfnNaeCVbTcAWXZNW96S49qY.01_ALsl0aOfsmMwn1SX9CMid4vo_3BOIXCEmu.Ljo34b3g3XEAIKlB3KL2sv5XuKQwRNEgE0LikxMO.Vdm8XFX8KcWJ1bEkBEp5meXFxCDHnoBajj3o9PpGjLsdd_v4SsQENp33p5_Q4zf3MQdGtklNeaanPkZoDAsZCjPWnlQ4fOJ6zd3NHWpTvYqrscpsBo.vorj9eJtBd6mU430Y9TKxg_vfYdXBktWYq7YQd2GhRdRe_yH4MbhSiY0SPleILpWjC.NKnIV9bGFqptPw1FOtftd6.lPehLHboZaGaVj6qMy..LPDFUZ_pVpr4QEdD4TELNxkwzKHNrBx_MqAgC5F9BZ21EqiY10lSpE1Vp5XjcKCNBbRrz2BEXBJ35lMGDThSoFAxD_QGxzsGxowemirYm1wYRKDtkQvUr9eIgHP8nhSObm67Df3G6x1LT4jVUPdYsWyLs9IX4tXqSakn2tg0hyx52nvpdQVxioalDQrQGpUgogA2c2pkr4Ifk4KuAKEl8gbOQqi49PUZ5Xcc6_tWPRargODh9f8ouju8jTGT8uaoz7Hnit8T_z6CWNZf8qU5m3CftDjNctX8uYu1l94RSV2zfSJ9DzRnQgny3dGMqNRtDSVvhEPCj_agm1QfTpTAfAA_3dr10Ei9VG4A0ktWKUPVaaM0OFzzwDzhgPcHgP834GzyH9NYs0BrPjLjlzPBj7h5ZiuMoleg8wDt95cN5491LrrOL1gOCIFCqidwTaRNhbSLwI_wRrbLEFbIHMsNMUID0fPYWeuCgDHI3druLcVQy7kEUpqFPLYZye1FsSRYf16FJ677qU6U_jtlO4lcChNnlKpacc8o6AKnAn9k9SRPFnMYASptv4tzhFLW6Em9nDDebdHl82zRCmQ16En4zY0jHf4ukSZqk0jvUMG5fpQQ2vFx7.bIfJgBBwtlcIzLpgUaSZe594owTdaYzGf_597ykIvENdJQAyjNynx153Bfd4sePvi1Dm3k7XMZ3PNvFMonbU8kuxTJf4NaMQlDFHrLVdv8UQQ74H__e82m4CpX4_owq4gIqyGPmGPKG5uowJLZEMVWSUliVffrETvIP1j5Kw7cW1QkPR1JD9K0vBoCcSa8yz0V2357oEtBsVUrZXdLGVo3Ix8QmiTjnd0Gc9fx3ZLQfDXtUcLr4PUnyqkDaWvraLY_GIInDi8tzOEJ59bAdacmsIt34RHt2ZXMotO_DFLCdnFCWR3MmRXYsJBWwA8FKObMY.KUC_tOgF1XKwpbeeKpOanYkqvc57C2BjtBCDTBf7eC8CygQ9EjyuoZghM5Vsa3pDIf_udZkoA6QnfGlbX1Z3BRF2JfTTf_YACdW.XgoOV9is51Bql0ScUgucXZu1cwG8fs7CLVdqOFYbotIdMsJh9DsOc58Hr8FOtyE.XGspHSMqed8mm_.5lEPAjWfRLHtUeY7_z0IfqrgHeUsMVqlBTAHwk4pmvxFJ5wJDic.6yUHpcMa1zodiAzVXY8GWXCvqfayk64lRWkozBotX67tVU96Nb_Sm.QiX5o3DakyC.LpAWtdCBhAJVIsVkRoQ1HcDIqbLQd4XEMGvZN4FOIlfvfSUMbLxQOo"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=92d99a1edbb64a6b';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, "\/?q=in%3A365405&__cf_chl_rt_tk=MOGxyiKQqTgyKRIqTQzn5N9uuHNUKeoV1.wFkM2qeP4-1744197488-1.0.1.1-ESMw7EID3CQZe7LFir65FYr8Gb.4JewZZ1Yp6q5sIKk" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>