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: '92e010247e230a9d',cH: 'i_E3nznv.e0rbq3eStEbawJiTtbjAG4_9jCQ5IBI4Js-1744265237-1.2.1.1-3w9RzDC0zBP5RJvgslLJPW103Q9mZnvBxHpCT.J1QGv50xAn9.T5wuV48RvivGmJ',cUPMDTk: "\/1513.65153?__cf_chl_tk=FWxCdl41Y7BNZr4aylUYOOpxEhCOkgw93_dUFqF4QUU-1744265237-1.0.1.1-aSJeWFY6sD14qujijaBLs.TGmohXad..kG.kJkmN_Mg",cFPWv: 'b',cITimeS: '1744265237',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/1513.65153?__cf_chl_f_tk=FWxCdl41Y7BNZr4aylUYOOpxEhCOkgw93_dUFqF4QUU-1744265237-1.0.1.1-aSJeWFY6sD14qujijaBLs.TGmohXad..kG.kJkmN_Mg",md: "GgkcrTXk3fSf.8voHv8XDXhyTOqV_2xolXmegxAze6s-1744265237-1.2.1.1-.0xzfJKKr0dqhXKGcuRfnqJ.cY3kA3A5ovi8nM56KtWcjpiyuzwIzBgFY2CRn.U1rKtZKh1Y93zm4aV2UUCcYiRi6d_MgZRspWTg.VUUe23t3kUzZSImplngUhC1STqI6ji0fI8rytlaBw1hP_Z4sZFxnz5Mu8ftFcPiQN22kGsQ1Om2YZpTQUWpPTLC3MOcos1pqKU2uQfJPWykgKX2g2vn1_8.UHkMXqYWf4apwSLvUpNV3jWYvVB1iGpQyEHZ_vdNfRxAa18syOGp93sShmfVpCDGbd4rWNYmGaRw_OaSOxxDBUlWEgITUrou.csu1lWKmUyHyDq4yFDr5DnG8lu0kpXgOx8QfAc2TfNOdz2jdUeyEAkd1pJp6Dk1P0OREjHN8k59__mHZUdA7bm4jq8dqSHBBuI8rC_cQrJhuCwr.98V74CauRa0kHOpVPjUp.JsmNBgLP3i6zfZ2akXXWdcp1MDcyQAjq7OJTChLTA.IkhQbCtGepYxca6pzyQjjEnLZSD7UN8PFq5S4_KfaGconqzxGGuCDA5o3T.c9rx7IAgzNHi_8e4VHB.ry5gr3BuMBfOfxyFHVourClWBQFFdtelzkDkHMY24aP.VhjaV9ijrP1D5hIpGXZpS0oVggxWcnOeMl8bDJvUg4XABZeYMR5teBRD0HGj.9OjvDW7sZ7cpu1N5rMzwTKVXQ0jydRgZyaamkvxJ1g1qAo02RlIjhyWij2obG1qfGyeisJlLhJndBrLiMvuhP8HeOI5n0ZfHQtRq2t7tRlGNqoJcnK_o8gphBG9pAzBMywZ.UpWKdAfKHQHrv7tElJJRoPPa3_GcjGlHWqgL7PuRLeQ_Ef41aH54ZTK4WVJdYAt0TszFvoLhjw.6kcABMKiHqw_PyCUia0BuwQt1BMdw_UFOoWsVWJ56EC6MrHbjv.MDAmLpWu.o5PJ5XM_RGlFaavJB3LpEUo9RQ1Sgzt6P1y6afxIIHTqHvHkPY.W0c4mFArrnWLx8ZPhsF2dAEKcgp7xPqw1b.MYdTRY7xWlQYe15rzPT6fyrjfzbK4.S8Vr5OAmYvOwZIipw0K53_hoqQ8m8I_es6jpZA1qVk7dcOa6vV75DpWhjLf8_BNDjI5ALClIBJ3AzKp43u5UZ6GAe_ksUWTy0AKZJEZUkr_v715NdFa7a6FTeDI03F3Thoh9LSkr6_BTrm1d.UbcR.XzKza7c",mdrd: "bprMCtdX4PxLwoTjJtrF5mUdDOa2RbfbKJPdvefYkSU-1744265237-1.2.1.1-RXIDCpOA92I1SGPXAg1IKH6jXd_kX8cNE8wXpKNJAuySKYgN3dPOMyURRyli_b0vAYhAzCah2WfOGKtwKmj8yiIDEuliNherITeCz553ZTxFs0UEGDsqpA5TAjFXAhIRCSK5b3tHbypLa0AKQq1eAypDNZxSBTuO2EWCLw0RJq3G6jsckqEOSOThotox51V_LZkcBl0COHemLR7Ge.9tjCAeKBUxK5iUCKKKNwGA0N7T8KK33jKxVR_YQTy5KFRDNES4nZSAeJVTbILYto2_huzEugFDs3pZc9SX9q2BYDzsiSBapzYAlR3rWiRQAlVPZaVQQaF1N9mse6bm3hGt3_VeyGNxhMHLLTkIiVBW37EfotFMKqE1YVW7UJF7ZaU7M3oKm8iaae5K4uHwovddBWsMkVkluXTU0.4XF10jPwodA3r3CjfgnPN51K6Qo8vB4VCXwn.YLNLOtOZYMgxNuxbjxIWv1o7F4Dn3si7.UXCtJ6HiKCl_QC_biyty0Ct3.Zmw2mLTKPg.CESdB4ApEF6BGphWmp1K1vSLT_UGFpnxysJO6NbhUcFr1RY2DpnekzUxiARRCxl0r83pzs41pQQxrPrPL9EIyue5ccv6YA6quLTQhisHlM3S91RoTymeCKTqzSep1p7HMXGL1BYGcvbsR0MEm.rXUhNKdeUdKnV78JBcz7UsR.3LJC0IQ4A5XDi9Mn_BQzVuEvqtBDj7wtH0FzK7e3CcFQQIonDPlJWDWes_dnqsZCMgAMffiAfk5CuXxCa2MlrRIMDhXNlGIXL9n7.Kuz4u8Oi1699NO740IxHa__5cyIaKiGMu_ipVR2atg9GneWyqznl_b5V.3sjQJnGsZ7R8GRRBfABZH7WGbb9gOeFlM5kC.58DmKpxAjPMNCd9ZerNiWzwiaMfitZT95HO8vO1fvgFBMDEQZdzxQ0Nb912L8C5ak6_B4sgC4AGDjuzza2RreYvhLY5nbuewZ8IKjLicESAsssxOrqanT_wmeB_v.6kj96.H4Byh.IpeqyAGw_UV4h.2yTjvqZl1ULQNIQ9FervYE0q3YF3U08AznBQ2fFTYJa95PpllBT85Bcw09DA_Wa3fniXzOXvHS.eyGJZI9ZRApZNGnr_I9_NZVVIHmd_7B68oprWCC4B9v5TmqlSivNuatjT7Y5u7Aj5P81WvXxV0IQt4SrR2inWKlm3fzfp.qK57GTbPQZ9.LNCnu8fcnYDk8kh_7VDfHRwmnnB4FNcjnp5oSTWWg69RWi5k5u6eXj9NHZNWJe0iqQzUVUpLQatEBC7RjpphQ4Nyoj3it6wm23kG79iQILIRtwwu3uTnMM8qJ91xWdNLDdwaYB7wSLeCOwJB2eBrDvbpN7hiPD6QYijCHCbSsJ4tQE6P0UepTp3iJ_hvFheEM.p3GKShAU6M6TQnFfr38x5E5cwdPya1NlpNDXvWOyagMfEFd53yl97RZF6Wpdy_HDEAU2IT1XwJfHX9LPnDZT207Rev5bJHsVGINhChFJWMTxUCzq6H.OZjDKhwM1_DgMowF9uwrYFt.tccHTH968I5hNqGbNYSXj.ys4rQJl3.DmxsL1gYe2pAQzOoPTrZZ7ku2UnK7Hdie.3ZfHPLjGPRNukRtqFnulQnJcyjzDgIEwhT7_6r9skZIiGTFMls8pEZyPw1HhvpMvqvPJmPwUAVtPZTPDJZMsp5FCVXtUkgPUE4SSYOSJb3AUIzTuF4ARvfoJrGtQMv04ix1C7l9wyNfFWAqoLno7mKyw4cvcY_Ir8PGVlhhlbG1J9HfyDdUY7kxz63JVmaJ47kAii6lupS3fhVecg6MNtSsMT2vbAw5N4nylSRXAcFOG_0eC.STA_AmM1lfTcVQkH5TdGd_._j0x9jLsvtUwOA2i2ibPeie9MQFIsULQZ4_N0ocjkAVso9RxQpZPgmadcc6bYZaEoawHIKAwmvPyqkjSslm1UXMZEypu3IiLH1ZmxztoF1G9iZvJbYWP8sjIlMYmEhkl0dbMO9o7rqFgETw5jVfL6aDYOGNtlLEMi7084"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=92e010247e230a9d';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, "\/1513.65153?__cf_chl_rt_tk=FWxCdl41Y7BNZr4aylUYOOpxEhCOkgw93_dUFqF4QUU-1744265237-1.0.1.1-aSJeWFY6sD14qujijaBLs.TGmohXad..kG.kJkmN_Mg" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>