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: '92d67f674fbf4cd1',cH: 'EWgIDRYyF5ORuXZv6o..3FvOGA3dKyxA5lxaOVnpgXo-1744164936-1.2.1.1-muhpYuVQDfsFrJ0OBToxRg3g89idVkJaT3Yzz8viJHguv1vDv8IQwDBEZLqRUbnf',cUPMDTk: "\/1272.90034?__cf_chl_tk=doWjgC5UajjvsF9gQh18eqwJ380VxOnsDJpc2I4WPTw-1744164936-1.0.1.1-S6gvVAl5i3zfVAeBMLkrhYAAC1EtAVtvzyWslubN2rU",cFPWv: 'g',cITimeS: '1744164936',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/1272.90034?__cf_chl_f_tk=doWjgC5UajjvsF9gQh18eqwJ380VxOnsDJpc2I4WPTw-1744164936-1.0.1.1-S6gvVAl5i3zfVAeBMLkrhYAAC1EtAVtvzyWslubN2rU",md: "GG6.tlCeBbJb5jqJMSAF8yBmtcxJSeaeFs9dJ0xdVWI-1744164936-1.2.1.1-mNASxtMZjg9qIrmtiAQu2iK6WjvF3wf0zEqtCR.jQ7rd6uE1RYafdF2OppsX2LF3SoJolZt6bk447l3sZLEyTPdthP2i4pT2QaFU3AdB2E2B0T3JF3naR1niefbbIGbMD48k_Y3Pt5oJlOPgV1ULcIYXZinmeGo7_IWegybInvL5MpZ2FOK7UhF0LUQLKhW3dcdDVKOsskZvHzDbGGXiK1kBUxFwKPNtc7Ez6EqsR39.YiujH6XtUNlkfqE2TLDHWU0S1Iwqqpm.ae6VCxAEssrTzoPzyNQ1uRa.YFEx1sv4cu_B78er1GfplggvtxZb6AUupqUYuh.5hQdsIHTxuCY_uOI.0PxzEmjg0FMcVHPkd4CzjwdvkoBhgDtBtMEkfNjvUSRF7j_c7NDJCejX9Q7KySxj9oe4WZBZM5c3WgfdEplJJvRH0TzDxXG1_3V3hADHSEg_3Ao7gDnRHlsQeEHjjfv6_lmpEbwMENyGi0.uO6sssiiJAHPkV4YihkIBfFV36n35BLUYrVEiia1xnDIsV4BPQtNsqRFn9uNqu.7XaXg.oc.L1cFuFEmhqPGgXSuSTsv_nl2yK7A5n0jpPbq70GPfGiwQv4itYETvijkbiZ22bIG53uzBQXf1WLQ4mheWcwJXnCoY6KDi_LHMJS4nDsCCMGc7YC6lt6gHS9ywVY3Nrt9Om94rbOOngAewGLhXal5yYwOmXf4ISICKtast30Red__hS9jEhkgZx1iFYvElenyY_kz.n2Nf.IpUJmZVdeLcEN.hB5HvYLt8rh5rzXi2x5lz1dH7OzC8Rft9maswYMzvAukWUhN3oq5MyBW0CWv9H.zlgg.t62IgTpa0tGAjujDSLUOS_AkjTdk5P1yn0SkKRgGfFhsc9u2LMOFk_PyoCy4dchf6qA_lf5W_dszJ1wRGZF7fG1Q2I7Qb9gPGYPCzG7GX7j7w2CdPyBcu8Zn5Kgnu96wTJSHMRKo_xQ0rxFymOS1vF1oHpoz3BwVcewgpX7Od7pVwlCU.fgCBbEGpcmuYQ4nj4UPlSW9x3ETuEV1Uxk8fIR62AwrBgpNk0yNZuiKICnuYoQaLx4uVu_iMReypLGKQvWJJrA1cSBLtkD4EL6sUGhBb1X5kPpBT9e3ABrp832IditVYnCnsSC9hPrJvpbXLVWkAx.7ZmNx8Mb68x2iJSzBcDqgeElILkuGXeMkEfGooYWtO",mdrd: "KZ0CE53IKSgGuaKZIfxPmfvDYEDM7c_ovru4BOHCyQ4-1744164936-1.2.1.1-_KbaadQ2prpNj8zyDF7_Pqc8AshtuE04qbuDFJ8Pd0ExxOzQaRdnYoA6mWfAYn1TfBfNAUaAW5KO.A3yPypY0AjWDnyH_YYobG5knue8faqn06zNyO_C6zqhKTK1ot0fpUbGshljKFfA4r7MYVnG11F92LEXTKJmb6v_wun_BHWhjgTApjJDHPGbVofMfFt9jYvC3qC1ONB1uRnGNgDdUPIo9qGRnnAQ7zFSJ3rAC.WJLTxwZSe47iDVFwmGATTE9MoHhaHVObx.ZvErqIuElrE1PyhghRuKw6Hscu1dApy09v9e72M_K.cvMa1nT6eEoWY82gaIbcURScSZs9m5Oh9X8y8ssmspxQyO.LZDqxyXzzNWU2XUDWtkHoVmQH7M.5cTl2.M5ofKggg0M6TqH2KF38ZSDS.mGkn2NEcvm0wn6OeRituxqrEXtWoGVce6EJgtaYuQlsPlsZYdg3Fow7uyWTBYKX4FNv13G_u5id95cGBZkBYdEja6716wET5zYuU8lu1OgR.m2XtI06cAKsv.2zXlYLaqK3iY43clE1n0hKXpDocH9Za8LpFV5Vm4Dup5PnPbFVaTMuxlnBD2Gs17AYdP8aRIDywBmAEVQBeI0IPCOHqMRU1NtM4XrSVAREvFO1XamJPHV_aqVQf.dF4sxBmgVgeGds208UNngX4lw0c33aNwqUnF.CpSINt80KKJyovw9.btVWUZBkhlmBCEKGt2klK9232F73m41V3DIhnn.HSPHDAQniQ9PWfZP51QXN1kxz00fioYEwW53Mn1dpTDmRc5OygZDKgFcyujwTJywNjoL2xdt3mPwTogCblKhFQwoJ_btBFjKa.rTY1qREjZDWkOiPJW9.8AxIpU7t7iemwnb_2peUqIELrKPmqCWSU.R2Fcj1cT9OeBDnsKX_9gNiaT3p_.uyw_G7Lwkq51WY20sa5id.rCwJrcOf8yu8vZLWqDjO7QgrKO8WdNuPWOD3dUHWB.QF8fxNFneIwEtonFcLBltZiqMpSUCXoPKbcXkqWE3TDWz.vfeedDyjp0vP8Tr1YCBFoycI_PwecK2DCiMMVG.heHWE_urUQd0.V2sva27cpFwfgpz5Vl6KYe70FSg02cBXZIcfZmUdsLRCuUv3wyR7WZEHy1_sJ1rbB3AUIFjvDutKin4w8U93ujFZ95CXPmBepSw07a87ordEelpZ7xR65K9waBwrH9Y5.zd9Gg_gTNvD.7h3VQPsg10rQngKsImpqw0vMYftJzIewTZ7kUk3XON2gZpJXdzXRANopQwRtsajMsfaPbpE8gFGYIW3.laxoAj0uC02OSrfH.WEJ7am.qO8cnFAxo2184GAmEEt_B2WFlMM8h2O0fABHA0DUp1acktUrEiuwwH8ZAmYk6btW2ISrBbrtup1mq8WlY2kdGiutptrpaUTOlLsJ5ppEEqKeBIT0tOnzG1qo16Rp_mQHwdAqLz.VtMoCZv7mpwyL3CdE_yhMW0V_5XnJ925VChuOCon9.FoaAl09ixvBtYqsvzE1T9vovQwy43p7R_LYcKYlH86edezItiK_3Hh3ozuJQPpuIJ8Y2F5vl3BiB6U06RHTWqgaXQw1EAeeTlcFFD_iJLN1WxlLpHdchQkFsu3wqitjxF0JJUyTP4Bcq882WVrf0NDTJCK3RhO8_nDRQj4o4wv.eIvsX1SGDSVIv_UI3IEfwmH8SWTS35Q3ibA0eWDwS7DET3MXnxpGtYJMiYQKis4PbgZgaWmyT6JrGkG0e8OfUjXrC1PB4m_.riIB7oMZty_rfKNjINz0PMawBEQydEOXkK3.wthJzBuxoeFV1.TgCG8MVHS2jLMr3RxSl6vnPuRLQUtdp8sbvTpG91ySUq7e8AJ4N2harjADZvsagL.FUbj8o6kA2NXqW0yVPC4vI5HXbVs2np3L.AM.BE4OLlKATOZBta4DO9NC2mQxNh7grQLyVJGvPUoOpyTmbiOrZGRucNk7FbEMOO0a.uRpqa9M.kwUssgghr4BOp6jC.XJQ7C4xevXCxVf53atlZqidtUkZCJb2wlH28suDH61lrA"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=92d67f674fbf4cd1';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, "\/1272.90034?__cf_chl_rt_tk=doWjgC5UajjvsF9gQh18eqwJ380VxOnsDJpc2I4WPTw-1744164936-1.0.1.1-S6gvVAl5i3zfVAeBMLkrhYAAC1EtAVtvzyWslubN2rU" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>