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: '92d6e3fafec2ce79',cH: 'w51LrJz6oL81UYNN9vkQxSPix.If_7iaPgjt3XJ659Q-1744169056-1.2.1.1-lajJxit7wnS0auB1imwGb3iBlvUjetBsVceNW8tMRzsLRbbyv_NUFu9TcULM4zvi',cUPMDTk: "\/1528.35218?__cf_chl_tk=.rWAmhg.51_XwLTdbzdQz5kXEr7KopJ2xrD1OlXDnuQ-1744169056-1.0.1.1-NMsgKkqnNuJrZDZlUn6EqGYrN0vukjs251y7ejVw7zg",cFPWv: 'g',cITimeS: '1744169056',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/1528.35218?__cf_chl_f_tk=.rWAmhg.51_XwLTdbzdQz5kXEr7KopJ2xrD1OlXDnuQ-1744169056-1.0.1.1-NMsgKkqnNuJrZDZlUn6EqGYrN0vukjs251y7ejVw7zg",md: "K8HkKhtV5bJa7SZr3DFNvV79iefwF.fbEseMQxjuxbM-1744169056-1.2.1.1-0PcKXPXob5ckeQzuZijEnJfqsK_BHulDj1gIoKhCpUqchdB5i9Rfi3xzPJloVyq968GNciBMtHzqIOw00JLFrMNtkWoO2AlMlF_RNlids5yfFChRmr9QH2q23dj8fquZrTdtJjSdzBkf4e41pgXhd5Tva9kfkw3jgtG20AmkzQtGXZiL9u4lv7tGTWNGpS1dJ_srJXkjuuBi45zhA2DpeK9AYZi.6wjcmPIVqDXTxHnWxdt3qmj.P4ObIEeGyxZP5EFDafT4Jiw4LRoZeqPm9.IPdiqW_VCdr34C6Ib59WryrDzHsBAAdv2tl7yw_mSlAjHbawvBtLdgHN74Jjp4bknfnKoBR0R1XfHeDZhL_wZzp6.fBK9pQiu9esjJrNXb7uYUYQ5Edx5S2yWxztztl7b5oIipBqog8iWtiJDIATTyn4BCyhIOp2pT6G15A4lFf.eC6x2E5hm9IQ17mi6SMblIBH_azZX4PMcOyEq8mBZkFElY_PPpcclEiqrhj67norQTAh9jZwuzJPMxoW4Ehy6pgVJegvhGdp9u8QBJWieg8IyF7ZoReXK3EyzkYYhte8Niq7_xVSo.mlsCstHV2cGJ4JEwfVCEUaOpwpNIOqyLGkUKFPdZAyvLVB2HQbGTnspnVrq5XLNpQOeNNmvLHFE9_gFlkEY5eDrlg34d5.Jr_.A6w5n.pWhzFBMdO084xXrPcTAMIWQ6Vc2tJs23ldg0XwMtVdWF.IcKVZwGE_Es5pA1XhZ1pr2GSU4esmrOq8QpMb59SIt3fwwdLYrZMhTXWROhWVGcMQwnav7MBoQvlqCN87bxZAY.cxh346Jtz7Wck1eoH54cuqJUf4exsK0uVNnHsuh8ojW4Hr.Ks.EY4PrJSeAN.mdSrIQQqQ8ym0zeI3suBeohnkk5QlRAj4eOcEdM.fYPMp.yqYZMYSwh2cTfYe90R9x1zjXZ6vLm1OP2RnioQepZGTOvbYaL15rQSNxEdcM36gyoQ5bIWHcopTN.8dYAmMbhi.GHgR_e45xOhILDDxWqVH1UHr.TcU01ttI3qnfWFURKndXuwxc6.Ts3M8LOl2UvsoDw8JXws7U5vWp.pVkvPOF8znjG_tnqXyOcwWIsunF6TsKMX8egdhWCMtgEkc5UL5GLAtqb.ettS0z9iSRksZkLiuEeud6c5izie4yZj7V5eSxcvoHJ8SKyqRltQRZWTtN0Ub51",mdrd: "gMO1k3JxR70lYv6GpdleRa65JHHhg1iZ2Av9euzlcJk-1744169056-1.2.1.1-g0K5TEgtIaqwm8Dy7BjU5B_6QlMyU5g.szo9NhvHS5akNaBlfFLXpx6bzgA3aFtIdyAbioElV08EXZL4AHNFecLwBknjmTwXztNXGwqD4tIe4maErRzMgG2tWVXxGcDQ8sZPfuEvRkeoqwg6UjcBatizif61Rph6d3PVQ4Bc_NGhPOHidJO18kqcv6LmB4a7Zq0ISF1DMWoyP7u8_tDTLZm.37ty4s8fO9AvAjnHRfcl4SEaQqfJmVpF7EbKbbK0Uq_We7A15vW2eou.kHobjN8DyvAOzWnirnCRpokrNvjdSO5oCjtzIwTSa_EWQHWMaWd0C_UGZMNUYvxZOTDkdV2CUmJ79Z0reyy8DSvLT4cR8vchf51jSsPAYpOzrCZr6O2ZljL7AYyxapwLkHhQrY_XHjqTYnX_YrBPpAzUL6XdAJBy2dQZ5X.QzfWfNSj.Z4opBX2IEwrTuYcGwAD0G3iLgiY.1LZKUtKTvtJuVibAiGLw2_tagE6Seu.o2UgQCQITsSi9FIn0rB3noGFM_uCWECWDUG7.qQ1FPR_TiXlWLksTaYcQnNXij7cJ8I5str_g.zPAHnqm9OnYEu2KVqLjd.BX4UtikVpu36ss2wPQul6o8kG2buuJjy.EAccf4D2ju.5yUA6.FeFZG6G5M3i5BNBTlZjfKfyCfUiqa1ijILksB6fGK3Yq6Me9bCFkAs9JNMvU4F7IgqOIxSDdS1VgoSb6dxqIgEZtPMtUNYkiOCVI4ltN0CWOq1sR_BW7nSOVmhEBqBsRipLjvti9gqp1SaYbk7u4pfWViMqk1mVcgv_NeX_A8A9uQtbQwj1S.41sxipiDEo3eOdCauwf4H0zmrtNCqCgYnxu2kHbfNOgABpCVG2QQgKLEFt9l0abMzquGsg0mm0BUCAzxgoHinRCGgE5XModBTxMinRn5eZ4Gw5ot2a1p31zMlJPe9HcdRcx9B6utTf9GeyrS5RC0A9CkWk8p7hwNyEUQ9axFNbKkKRm.jnSbZ66QRuPyrPdXssXOEIGKfW2ylGnePUsVqirHO.Y2afkLV1he8Z8GhnxlYJOcffSKgDsmhx2MTllDexRe8MzWtV0gV1ChY7S1wjwqCp9xrjyLMqgVQVpzYuZFTiVrGcsyg9YE8U8vzlKWwWCgqCrNZx2UYlF4DFhEo_RC946_k6jDqzMunUbJfiyll7.ahNuE_W2e3ymLlOgdvPNdwMZyyKQNTgBQ_RgC1etYu51nwgAF7S8__qApZXS7tYpBAh956lBAsftdGHdvLv6DNZsYMg8Ij_ffkvT7RiQDRr3P8eHTbMPyHrP4pLUuV.or47sBrGBKInmpiRILyp_nZoiO4_nRi4.vGp4y8P8QlchDvUtOJjLoUpBXrutFT88E9tIhinJ.J9EuGUDDyV_vmz5LOXaxW2CzLc4LdsjxE9LHSqUknsIUKe_uFGx.7ib8KXZzFK3rmAaJ8KO0d2XSsm753cvCMqQeVU3c3wy.XGpPnTgvuZm8yRpwO.tYYjIa5p2OpwiB9dABKcf.02TpKeAfjSL_vRF3cv_loEWuIt8wZXq2JLHazSb1U9RCJkPBkuN6rA1BG5R3.lmGczqsfAMFf7Ix3JQFvxc7RxaA1L2mHB3T1BcCls3f1vSCF_NQjtYyjLrXQk60N0lb9cPbH_ITgqTJjQFwj1c0c4mSX1ih9WU31y_8PXpluK0k_xKNR11m4Bqqakxwqsc1sl4ThcWgGWR.v0gq6tnsz8fgm24z_FOwotW2KimOKKLOsNKKFRYQQTVHciIuFFLhNmvfsb0kgvhNA2KWvs8CkUBgyylqtjYco9Xt9RoxukteMQtDH.oPvYF5r4sbvkrlN.WlUrjrfy_RGzmspMDYh8z043zFZfztwKYoKaciIQuY_WMJK2bW.3hZ99gvZQRSzu7W4o9QBf8rFnpVSeLzKPN6IfaFaIeHFNkzViWwmIoy4GS.2zZvw2c71FixYrZ5l.Oa3FhMFEc0ltzvBosyQROkanX1yHJVrCjpcZa9Iyz591b4HyZ7mN5gyPPaw9L"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=92d6e3fafec2ce79';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, "\/1528.35218?__cf_chl_rt_tk=.rWAmhg.51_XwLTdbzdQz5kXEr7KopJ2xrD1OlXDnuQ-1744169056-1.0.1.1-NMsgKkqnNuJrZDZlUn6EqGYrN0vukjs251y7ejVw7zg" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>