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,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIzMiIgaGVpZ2h0PSIzMiIgZmlsbD0ibm9uZSI+PHBhdGggZmlsbD0iI0IyMEYwMyIgZD0iTTE2IDNhMTMgMTMgMCAxIDAgMTMgMTNBMTMuMDE1IDEzLjAxNSAwIDAgMCAxNiAzbTAgMjRhMTEgMTEgMCAxIDEgMTEtMTEgMTEuMDEgMTEuMDEgMCAwIDEtMTEgMTEiLz48cGF0aCBmaWxsPSIjQjIwRjAzIiBkPSJNMTcuMDM4IDE4LjYxNUgxNC44N0wxNC41NjMgOS41aDIuNzgzem0tMS4wODQgMS40MjdxLjY2IDAgMS4wNTcuMzg4LjQwNy4zODkuNDA3Ljk5NCAwIC41OTYtLjQwNy45ODQtLjM5Ny4zOS0xLjA1Ny4zODktLjY1IDAtMS4wNTYtLjM4OS0uMzk4LS4zODktLjM5OC0uOTg0IDAtLjU5Ny4zOTgtLjk4NS40MDYtLjM5NyAxLjA1Ni0uMzk3Ii8+PC9zdmc+);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: '92d96c547fdace6e',cH: 'A_zxqpStQtBKxX8AN9cZ4zfpGE2Vg3GRmOfsUR6EErY-1744195612-1.2.1.1-ZNclZM6CaeF9NzW.9lgzawVShJ6zdDkHvhCKN5ca0bgtRAoNuvAvqiKS4qUv3pNC',cUPMDTk: "\/1435.65128?__cf_chl_tk=E8sqF147jsGrHYgfEeUs46fdKMhop8bpeaaq9lqQfrA-1744195612-1.0.1.1-bnCNzyy3pvDY_iLuQmF2.gMSqMxn9LQkCZ50BlaSn5M",cFPWv: 'g',cITimeS: '1744195612',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/1435.65128?__cf_chl_f_tk=E8sqF147jsGrHYgfEeUs46fdKMhop8bpeaaq9lqQfrA-1744195612-1.0.1.1-bnCNzyy3pvDY_iLuQmF2.gMSqMxn9LQkCZ50BlaSn5M",md: "JFLBFAOVz1aD8sRbnzOD5lf_HW_bCZ.K6HiPp7198Vs-1744195612-1.2.1.1-uI_4oAvh_fTP4lJiHAHQ_N5VPXstoFAWZF3KHbhdvezlUNGlhXWzu7xFnomeTMmo1bmmnORWmzN9irnakZoUCjmERWNv510fZs5SCObFHcU.0iGdg4KgkefWdittYzVAYiiJQsOn7ZF42f8I1XgFuO8yx.OR9austGb0DPRW8F_pqQ3OV2Mnq_NIP0ohgIMNs9m_rOACDlyUVzcfc2TrIAmfFFql6ToSJ9gSKBqAABIMmJnJLUJQAT1le01xuf.W8Kza3RousH97aQXMaMHTDG2pfDW1HLsrskuO7fFHPB2UdGoaZVT4Ctpt3z3xMHKqbuoQPStaOVsK61XY7Bqks21YD3UbrsWlyHJQactPK_OWrxGLi5V.lRzblt4tND28Cj6rdR.x6mnbdsgTn7SjzCuooB4tq9_rw.e9jE3cJYj1Wvp4euGG2rdpdTKNLZy8s2P5O9vWXIzsZqOnEA3Qzug0jNlSyScse3Rm.wv3cMkb866MjlwJSp09550Mfkr7zbyuSNaHYwT9vfyJ6CXyft_PR1wY4DYGKKKhMf8YL8ACGlXOmHwdZW4Hu7hCLsSJPZ_kE22q37IGDZzXg7aIs4QgUgDxPqPRPkCYYSguwsxER4onPx3VNl8_TgAatYbG5YP9xkdOFcPh.6MgPe9xuoy2ZEjAsNh9G5OtDTU3J09T8hAoOjK1dawaGQqaohttxL5._oN_HlqORbeqAzN6..aEXpLj_716bU1oe_8HoVwPwOVoCDhMnDsVhJFMdzM1d2ZaHyafgmXJEHcd1UXwTVZ_0L8W27f4I2Km7Iwk8DJC2YKAPL4emDmf.HtuqIny4XxjkoMrbtqHks3vxutPgLxRLrGYqUHYoSp9L.FcPHO2aoF6MQa6w5fvVsnlIh24YpVq4ZeWhlPagCIeFeyqq6qY_kmpK4OYkGpmXLKsarY3VZOxwekn67zEGAtrJ1p0OMt22TeS5MVUxfgC0ogFJqyQL.5M_O4lHosaDOKFL9N9WgSF.RjqFWNOtbQDt2wDTy42MzRzfcnOgwccrEI3xVv63f33pV818F95ODg6XiTEmsXs2tVl5P6fSjzGUCrnONE.PpETdyjrnM4XF5Ip.UW5fqChXnJze3wGG.wzJYXRkAZ7gUCQHsvfZZYNdBrrkF5TeyIZNYD6jSY8l0xA89rarMHCweqrFdMt4uocisBe9EVfwZCMbmhsA8YLF.Ea",mdrd: "_ty8jpgQj6mYVu5HJwWC.Sw2zaCZNWxMOw_ybwgRTCg-1744195612-1.2.1.1-26eREAeSJqa6XALRNJzjbVd_MUs84pAxBIx4n0xc6Lsuyp2_rJpW_hjof1678CJ7Zyo17JbS7Ovg.BwIrc2AgSxYIWL0RYaOiCOegiMsqcHUjVjd6tkIPkBpyBiioEZWFV3pVQRhcBmr46U1qBgDu5fJkZL48xWSo33SGUDhopHCkkDaWYzQJ1yJGZksHT02ygF8G33YS9NDMh_R3QJoRqpZD_zNMyGJ3mdGjFTZKge.3xv1v_i2p5iIFUZfbZgX9PlVzzkTufgdDvIt43NlVixmyY64Gl3Ft6jE.GaHcZPk5lox1KHIbJggbtEAA8pkUX7Z7tpioF.fMq3fxeL8F0Z2L7g1Opn7IypAvrJBqfv1WsINTdf.j9tvfZ3hQ3.StBgd2V.G0GnjA0w9TRhjd.4wwWJcAZdr6rz43wLIEUVacYYPgSlx3QY8hbmesamQWIp2jWHr9_strIQopbiIy_iIK3.kM1ThJqxpsRV.8vxpS_Wthb_lUvxBWZXZj6jB_2me.s2ldsAPoT9hhup21Q9G4p2YumYtWeHxcrdxkc7jVqLjFb5xNoxV6riM2WqpSbQOtUmkJH_BYDq9wqSFoaGXKU9y8Qyt6rP9QGj1fM1E_SleJUPLPmxSDh_PmROs16647w4MYhpYBaqZ9YUk.WdQUloerMWMzCuoSUmkC0UGTrnRAmNpg_7faFF_U2nAXIT8ba6afNzjtFXEEmhp2W7rtbJCcChRmJGt2vTx6.mhTCKvJ4xdOIbg6KhuXeGcgbybtUo8cG3Ud80Bqn._y1VPMi_prAx3Bup7lehd76FU5z3Uz2U672NxrFmzQBj01qGX.YaVHZJ6DAEdf1.jxJRQrHnmr_kgEF.1kctCquVTLGbWrSheFplgln90M3Qc7pD1WPN8sXP9.zC6thl4tgj10y8OWG_XusNzBeGjhyk.LHIj5Oh24JZea9Nl48FYEmkYcUTgLdIbEZA1fK2uN6iahpzZD1nEFDh3Z_2N.HRABbIgBTXOPIZcgK_iTmMbGop5RfrwgguNTvik_zdWOISPb_9iOdQ5Ej0KsF7vC9eNbSDY9u.T.avAyJeBQWrjAme43Fh_jkCysxnpFP0Rsqz5DUI4e2OnfZ93zi5CI0j_7RYpTQ6ww4XLKPtu54MPIR6tljFXyRrcVDguJNttVpwGgTa3dVxngHjA2iuJ8k5xOBIoFS6j0n62Xb3DM8qyYPXTetxXA0VhgPh6nqXlA1J9Mk1X2wjMwRsGWYA8Cyo4IUGI_KwXhDWTDKj.vJZtFLMEi0WIoR42X86oUPXKquKnOmS58oXgkd.B8hudXffJR02zEGpavVZHppE7D4G7A9RJrqlzKlgx7nSjk0uWdtomal8Vmy6YuurH96hDWeYQCoCx41XeGTEbIa1ejBR7OTLcy7urE1KeuaBpTDwZC4lAmJVW8mUmpfQpBC5jgQ.OyjLQXFFbkv27QhodDM2BsWAhys1ewGFkPfZ89wLB14sCxgSS0P_hCvv3X3VHS6M7v_wu0owzfRwHaVgdYt86hqoFjoC32aimwWfkOFet_N4e_pMyjr9pLQa91IOu_DZr_bEVAaD0Z.7JW84r53ghnmSTdu.I6gK3cwBME.XmKQVAr2umy_m32Aj2YcBGQfuOOCq4zMVcl6kUe2OeMFDxUEgQ9Yu0jmjT57L_BPZ9FjsZDCjm7SpohPTmHuPdF9ZWonHlOWPo4CXOiFzg_qyt9njdSBFEPJyRLAV08XCyYlOUMJR3v6BA.SZgrAnkRRXnLV3SvQ2pPOwd7bB.aUv8eIcQ4t2JSCaUw1WqywgmTIJHP9VGCLZT4gC.nyYa4yn3LlN6a7h.xuTgi7ffwp_m5o1YH0jM.RZPr2s8Ghnun3K2LDnSIWJ8Tkco8CZuZZVJ6gF7VY5ilwLqp.hJP.KP0wvyatDMHMokGiEgR7T4iaoVCcJIjitdwpzDvrs9DYGsaVw6pnF2Cdl5J9rX5MIJ56j0tW8oRsJrjeUsqXT3im1xJxv7uY.Ttq3OIonT_Eg"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=92d96c547fdace6e';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, "\/1435.65128?__cf_chl_rt_tk=E8sqF147jsGrHYgfEeUs46fdKMhop8bpeaaq9lqQfrA-1744195612-1.0.1.1-bnCNzyy3pvDY_iLuQmF2.gMSqMxn9LQkCZ50BlaSn5M" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>