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,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: '92d87154b823cdfa',cH: 'W4RwGdk1ijBVcsNhHHD_Rb_trOU9adfHR7.fzgc8tI8-1744185331-1.2.1.1-aZ3ApLtIeucIHZieUW5JJTlvZ.oWCDcJrwk0iRV7rNHOmp1GOIF6q5CtY4CLkSB7',cUPMDTk: "\/?q=rf%3A5839550&__cf_chl_tk=_Q0FXe64s4W_uv4iTOY5s6qnQmAJ3pAQ9hyn.YdlQhU-1744185331-1.0.1.1-0WrIThVNZ2hRrkfxlABwvwCjgkVLgwaZdS03MUwS3WI",cFPWv: 'g',cITimeS: '1744185331',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/?q=rf%3A5839550&__cf_chl_f_tk=_Q0FXe64s4W_uv4iTOY5s6qnQmAJ3pAQ9hyn.YdlQhU-1744185331-1.0.1.1-0WrIThVNZ2hRrkfxlABwvwCjgkVLgwaZdS03MUwS3WI",md: "Z5REoOeR4BccUNwGYwjVCVnPWxuuWZ.LgT8do1INqAk-1744185331-1.2.1.1-YmNyr5CV5A.S5rXAq9z.5yUkAfXOqKDGPu5v5E23jrd3f_ImUfEVVdgEKjzkiMKl3C8Mm_s7LLTiezn1nHV8Jtq_hkt.tA1fHP04WBeXoXNrl6qbYolK184s7izTxkMCCpQbKJcXVJn4VtcFtzBl3sEZzgUvsiqPKJdvaJJ7hHlSKceVZRAcryI3E4s12NDK7UpkGr6rM_PuG4K1VDjheNjLXZP3zT2kD6hAntK2.TxD7xOyS9Bs0FJ7LXa1iAVLHbe58Uu7l5vDssA3D7XsQcMGhDxEHNPMpu3MHJmPNpGYOifFpkr8733ccOhVzJG9IOP1.bb.1lkzGHt6l4u.0eiSwwDMMj23BDrtI2c0USj53YGTSTO_jPlA4xGxd6CoH1A_QPGzneWRcGqZvTd5EjTkBwKbD6IiP1hHP1rCJFxRHm1Eh43nOnRHR8zreYbGKL.p0Pw5xo3KkTwAVnGDd8jt5CdG9DZ4pal2W9RW5WUmxF2ZpYKKS1Rl9V5BbSqwiavMgpNR0cX_QvTz3A45Jh02_atYvz7jGPrkF4PsgCC3Qnz10WMFdWveAf90Kpb2TItqfgO3uRsJtksLk26NFVVy5HwjUVU1cp3n5idI35spEMca9lI1LPiNPU7tTNk5SE4LpWoUFvp_lEsD5fIoJOsXc5Hcd3d6OYsKraMQnJgA_OiGVTeeVTqhbc9LDP_DiDWaagm8hne0gldFHkatm_MzYj9CmKN.Z_HXULKz_E1AX1MG3sF5We1wulGKGC0045.AnK5eCDVW5bVceHdpA97D2XY5gZseFqZfUFCPrtixqrq4oNVWtiilvzUjr5EJhh6BFbPiklhN4R2efeBvj_hN5oobhvnC4RVh2outlEm1l91O2K8AAhvYhCrj2kr1r8dkZs9B7zjKQRR3bwfCN2nDwagbYCztHZNLj9JfIh.g_lSrzW1VTJMwouSrT9KgJkj7hvtFH7wZoLJB071uJ2bvPHccVt0bKDMRHbyd5d2pqFojuRPfnvFAhl2CfbJPJYd8j4R12cOHACpgFNULyke1bFA3ufX_jAvZJ5uEM9jrI3mfo5TAVlmbblUgkMr4JcHZBPR3ELtOjIaAvrtUF4Y8BxHGddNDhSQHwhZxIxG6J6sJDz4gA.kyHnRPZWpIG.pZuSTxX2zyjUO8hmT8Nwt33QYm_LkY_MymngchxC9tt1mb3y3Zcrk8zilYli.O",mdrd: "mbWXtJC9Ow_v.p6_Ge09PXOSz4nGalMkpPpOgK8Ra8w-1744185331-1.2.1.1-WIYOyD.p6cXWFphRlSi0NJxX21M7cC5bn94cs675WxX6vNNC4npopE1Z_F0DCucBlcEbftdlE0pu7wB1I.jlGQY_9U_ivgHqtJtZkMkUFkorwnljP3QVQfhyOHb7DVv1NMHgUsZ5jN.rTfISHiiJlVNUQUfquJmzrhvugkEAjAmxtpzITm1nfmE_JUGy8A2njqmyUONqe.2xpegJQrMekeWiWYppnVNets05DNja1QBgAZRNZDG0tOMJVFgNWTVsBfuTrv1OU3v2cc8a_MKcvyd5nFx1Xy71FivJRzg9oAqtV0QzBDr0p5.Al2VwxD_Peuf0mOJTxekjCwlZpnn0A1wK7w17SECbGZVGB9H0fUxoffYLpRcuSHHDYPgzXI5WCKAmgwrs7X.xusH3Xe8vWfB0zxW4xL1W82GbORh82Ew3.yh0tspwmORw3ZsMjlijavssCYMfsONiP_hVQQNsuwo2WfJ1Xdgj44IkOblVOD4_3ZXdiuUzhAlGDJ8otcvXBcIU03BTCDeuAZsBsHOqCBMEZlPi3F8poZjtEA0CHrNW9FLUzZtPE5qwJ6.kBgm23lZDhujZ004_r03oOxm8GDzPZoW0IdwLmZXMU7hBOLh0uK6bu5_xV.XNEvscnPT4yvc9nugf2_NUIvZxd3AtMIAGhKjdI7yM9djBOzymxo1o6Oc5bfWPg7zg2DZ95y0vWKvL3biB_OeYRj6qZ4eo3pekjHoF53nlWT02qiXDpjSlKhmDgBla8Wbq1OPOdSmUsQD2JXdXsuDQ1_dDeo2PDaIbDboJOCCBhwi6tYfmM__NIVneySH4KST4HUZgIPoHjGtvDyC9BFJjKzvTFa4ti8q8ELgk7jJBVIyr9Bjg.1h7YdHtS6A31_413TC0so1jrdUJn0YepX9GsQjm32MYIZ3pbgtibHizOYTy9Hf97AGrisX5WqJqxybj2F3PcQDYL5lLS7BRcndNY4.uBngtAOroodM.dt.NtNB_3ZlXiqcqKd6EZP2MjUhYtBOJEgf0VZAfCSIATsIAJ1WJIyEBPGjQ.TFcIWnaCjl9D0LXtMx6TUIvhQGwfEa3N8_9K.BAmam6h21QgJwoT6hiNyoJLOcKpnFdzpqrsdhczKy9IqW0a.ySd_JzOPo6vqbQxTESlXlrZeUsltyZV7hqKSPTkAL9CggFQh3X3TYmGqhbVTAy8eqd1BVFM2JrfmMDQa7WmacJBCm658YnGlSpMX07YS6j6KYlOqdERIAal.OGwrz3XfRy5O67IOIATgUy6_GEi1xIVyw6YqCvBle1FnQBbtRb.v.TUGyFpsXOPpL2PkMo.e6FBQUT86q4QhZ2V0PJM5kq6yYdwl3o4RymjgRy17nTrxeMlkBpTge.TRWUcaxbHpadwqehPCMpEPJANnb_D8st3P.Ytw_lqkZhfAlALS_peCDnNw_kzSt861LQpqVx5J4jy3lkoBKIEb0lOjOWes8rcO3BNvJameMViJJKwGTaR.7YvLsjh_hXnFbUT4wiXI7rwdgATZaxKfTCzYRiUqxIQxy6Eq94CFL9XddGNU8GA.QFtL2QOr8x3FCzU1HObVzDihWRdqoqzQKtUGdXrWLihesmNwMk7OGy2aq6baPEfhgah0Q7OCemq0mUHm_gqHbY9Y6_XbtnTHGjDJLImdcKIguFWevBtRT4cwOuSYZlzIlnf2CennNgU8avkQABqz8vQbl9rO6ATrZgoua3.rb_pm6vl9ruOW_.620vn7oma8JiXaeVYsRZN1yuvvntvLVJsxMtbWHEsS1WAIiPoJ6SWN5W34wligGA4zUg6oOjON5Fdk4Rco7ghw5DZtjwA06T0rQt2UfvYN2vuVUmt2ViWSfPtj5IvdtDMMqZB3ZT.2fPLdOx8X7GdY0qmcAW.RGOq3tIGf.c43onb77j86yLJXTnjT6W99KX4Lqc7g8StSGSlYwnDZNNVwk.1c1yWlT7tmfG153hLMR6UjTO1oSrqRe6vrmTOGy8W4yXVC2Ep5i3iG0a6gS7rHsRIysR9pkRAwOxQg__AslC8FuRjc3elPRRkMmFSlC_2.f6RA"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=92d87154b823cdfa';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=rf%3A5839550&__cf_chl_rt_tk=_Q0FXe64s4W_uv4iTOY5s6qnQmAJ3pAQ9hyn.YdlQhU-1744185331-1.0.1.1-0WrIThVNZ2hRrkfxlABwvwCjgkVLgwaZdS03MUwS3WI" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>