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: '92d73e6088e33fbc',cH: '8Nx.vJMwACNYCD0VtiaFGm7PGFxsn8FnVH3suAkqMek-1744172759-1.2.1.1-7BBEUNn58a1jXPgVfZfYGt_tQF_j96FgD3ZDsv5s2ANTykHgoh.45qhbm3htGecd',cUPMDTk: "\/7780933?__cf_chl_tk=.TWfAPhLyLFpXL9ofZP2wMcHuqq1qhKIejiHO4vFiRU-1744172759-1.0.1.1-sxzNFH_wSEPS6htUwGFAUMigc5VAWlIv6zX6j9frZmI",cFPWv: 'g',cITimeS: '1744172759',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/7780933?__cf_chl_f_tk=.TWfAPhLyLFpXL9ofZP2wMcHuqq1qhKIejiHO4vFiRU-1744172759-1.0.1.1-sxzNFH_wSEPS6htUwGFAUMigc5VAWlIv6zX6j9frZmI",md: "KRK8SfyqAFGaGU8YYe3YxMTM0OaGKjkz14Rwe5ccloo-1744172759-1.2.1.1-lz9UhS3x9PAFy_LKWoMCbMBcQJoR2jx2N7ze26uYAuzgdxEWL2IpLmr9PRDjbAhQVCVQ0V0_r4rtVMFMwBPXpNudn1sxucFu_b835ctdpMpJimJ9OHvs3ZL4.j15utcKLNcg_QzUTZY6MgSC2U050TMrUb7LXi9oGzATqalSuwjKsLOshQG96d6SmDf_N156Fyqb71Q_h_pOXsijf18WQrMRBgSSABGAPC.e9sEPIHi5OGiRAtZ3_BqpWeGucsvCnxVjQHbz0z.Aqry_PIYuHfK2LygLvRFFECpzJWxtoHlALz.InF1e56Aj8D2kwDtuZrYM0cTOZI2JjjuZWsgEiOtzAZazemsFditv1OawfeDQDUXJHvdakNNZK8kWBnDoLPG1Uy3skJzhAZCZQpZpXEZRYhtSzJDnatc4P3T52nR3G6abygLxWy9YDFasYOs2ZKj.57yWiU2ZtfkSIsN3EuW9VyiwXxU4Di3aHjw6yBU7W5swHCVohiU7ywhgYEoUey8XWw5eX1dEwjubPoPG.pso3pYtD0MY_0RqaWj88oGeuCNYYB2GeOjt2gMd19m26O6Q51D2vp9E5DCb0JbBVhR5MgPw9rJdwORHi.DLj5y9oLKLrbqTvbWMkR9ibeha8XQfnTJKsa.bzZ833WD8Ca4XzN8mt6BHZQLEb8vKA5VMKYZ5EbtV9KNvzgGdhfTxcVzegmNmC0_6BaSIc26ssuj_QdQKGSAdrSbes7IwTkITtcbSH5TkjjoRHPGDLbomk_mL3UsqxJWpLrqR12GHLRBFVqLNkfqtKNJtbV8KmGXLdF5cU2zPf5c1qEvUm7WoEYw25WYFhIRzQk59RbtuRLKcHivS3YTMxJ.hM1sHSHiNGUKxr4ChL4IEVUS8tnD6dMeFKdWykUt8.DYMNBRUm9t2SOIvaUibq4iSK_6RY5Ao4lzY_w4g7vq1qQlKplWRx14DEGcmU1sno2NomKwPdLbwWvps5ke5dyzpwp1F8T7.YR1YQoI7XG3cIdr0dhmPn7JcaGFVdrZ.OMhzqKRYcvVkocUaoinsS6qX8ibYDF0dfuPsB2.6NehseKVpZm2t2Nsc.eVRTxU.ryyANoZuFM8mm.ECYTBLroomyKa0RqNyJHOiMLbc7MxAX0ZxiTT2yIe3eB9_59p.nIb83E5Zh.PDCYVMLy8DhvVluoMFoco",mdrd: "gPS8ko1tjd3qYTlkYiaKNJdtMGkV_q28F_v_MMVVS9o-1744172759-1.2.1.1-NDlqsXT2SHMnWQJe6gBygQ02rs.07HGlmxACbuEwEnnCP1PP0u6hVEietci1MrOMDJpBblkLRb5RH9PHGkIu_P8eLEQxwh1UH2dXW0VaU1FLWGFWfVuVEyNKUFFRSbJGNLfxVwI9UMR5u5Z1_CmexPY1IrE2WHXvesY_UkLwfteXRKCS1I88xa1j1n4sZSMLxH1uJ1Sxv50.iCnKFm2XGjzR4d6POaaoEk95uOYKbWElac6SnKdw4ls1mI_fvOxxsJPY676a002f8bnrUrqkeGcLjAT5gOPaDSzxk.LIfkpyywwhdy1f0C5gGOwdMh9y0dyBcOzeOxECW1WOCyWG2u2yooyKEcakjNnK4Wcq2OB7AKOEkPFvpIHKG2_r530Hi80kAEGlNdZX6C2TypOF03QFUAJ4FN71.srUnzhhEd2WBC.SDHIpSIQ1Q2HPkYwL7YoHEBVwgeGSTnjoB9rJKeUMzokQVqWRE3bGPyKNX09M9.t205bOo1oi0oopsWeCgTqvR01E4wh71JGKZF0IQbtqmfaTF.1qZzSC7qjQqTIFXfE0gTRw3nfO7JXsZ6XQpNYQI_rfTnnGZ6Y.gAfotsHkSf9lqGL6LwOr9WzeNd7TWQRGj1vhtPEq_.q51fZzWbqc7d4.KW2KMh2E21HYKRAMnPbGTmB0WoMNseDw0NL7yGftpA51tdBdjWfw2wUF6Chypswbo4N5BvFnDXqwze65grfiLVC4NI5kBoRIxTs.0eWE7D._6Hpopb9PElMj1Dv50XwdxUxCqlxe_aFHiPuqRvPsROx5Fegr0k6c7XkoZizd8D.bbarQHKbEoYhPLYLM_tuKARbFvX5Ng.uVSmQqSi5SsgjBvdzIbRT5h8.ZQ1VgUD2smO38oOA3c.S2TJW26a4efONFWCy1rirU1UZo6dwlaYh_YhMOC_lgw37awOrpprlhjwT223VVevKdWD8HMPDY7j4a_OWL_bBp38uRWkb94.yDPyhxUFd0F3wU9lHwUyyIPmopkwykele0HF5obTx43CfnWbNTsDVx8zRmn4DHjVXVDXeXDb6INSCWWcbSvinWSdG8G8lm5qaZN9mo7P4VHNN6UA9UOyTSI0XIuMpkiKtAmKT8EZJkfUqym5L3fEte1ta.YjjCyQvc4TMK.k7DQ5FDgbSAusGMGmpKTdLDVOIWAbeHh8TpgSPLyrqggIDrviFm2RUlE3ZSYqGiPhjMjf0R6AO2HsU5RL51HUP5XkZAFHRk9u_u2CqnioiwolW4ewRZYUCTBw2XjklMC1rbdBhnDel0eRJ2xa3R8UfzMTKFn9QWLlzmJUnBP9BqM1xbTOGc9hxjaSsHnxHZ4Kg4afFdeka6eSA1eV6czjKjxFKPpCpAa2nd51reyjl_V9a91QdRrrcJi5jvFejhndG4t62eadsBUyxUf7Hjfsq5SjKxfNhwmE_O1LA3CoQcuOh8VXHGIfjJs.uqtIR8XpFvlHI6IY7gHvKAWS27OKMmnq5vyHJqnrJA4wuYcY.osCPWwOVyuUrwFDv.E.yZCf86mhQwOuyfW5sEVa3HyqFd9Fm_S5IJ8Do6ljSIeiDjnK7Km0lB9vdzmWMJUubwjhQK9Tm3euYWle.mm71kYZRG1xRS_zSXjmdZyM7d7uxz2XxbrZVEQrvixyQ9ZxV8rYB2Zd2a.uu96e5CbLA_daCYrkyEnqHrUgEM2aFol38kn5O_IvRtahS9cefM5Fr_mH8zXbJDP0Oxq9v8YVr7lWlm4dcMK.uEW3ECD0DjSHIhcNO1SF1zyg920LRDtCg3e.pf7RDuOZ1bBrWO.mMcOnnQbjMCMnc2uIQDgj89oWyFAzquravfL1WJeicivp4wka2i88tpsEL6YfmftghxuS4AYc5cOvCyIg6VrW8bQON1B356XQ8J5ioVS3bTHboC0nR2JYJJJ2Ir02tsyeoB__uVbsRm4440vKGOh5jjWFgDSEVeRaO_wEiClrf98bny9VwiVNAZSdN2FmH3_.UmqfQ9xg54BWZtCNnCWMP8O4hr5dC75.xWvqz1T3HM"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=92d73e6088e33fbc';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, "\/7780933?__cf_chl_rt_tk=.TWfAPhLyLFpXL9ofZP2wMcHuqq1qhKIejiHO4vFiRU-1744172759-1.0.1.1-sxzNFH_wSEPS6htUwGFAUMigc5VAWlIv6zX6j9frZmI" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>