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: '92d8f3a4ce91601a',cH: 'E9tcnmwoPoolFAH6nCMLSAwg5Vc5ERYKvUykH.Yv8FQ-1744190669-1.2.1.1-32TZ57Q8mlPVzIPT2J5jnvn7werleURqZdNvoOezEZie8ajffOPXX2clKF9YkzO8',cUPMDTk: "\/0064.19802?__cf_chl_tk=LkiqD9qC.51zcN66aGvs8x18FnNVpRQAdFtAm9DpkXY-1744190669-1.0.1.1-F4C7qqG_rozcyn0qUWRTJ3quk1.UK57h50ID9ebB6QE",cFPWv: 'g',cITimeS: '1744190669',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/0064.19802?__cf_chl_f_tk=LkiqD9qC.51zcN66aGvs8x18FnNVpRQAdFtAm9DpkXY-1744190669-1.0.1.1-F4C7qqG_rozcyn0qUWRTJ3quk1.UK57h50ID9ebB6QE",md: "s8sJpMBpe_tQSsUdR3f07gUJMCBw4b3vb5v89jElEFo-1744190669-1.2.1.1-ivgyc4g.wSRgfDkMSxrHvqtOdpc9_gixxri0DZp3DEEjSSMeWid1ODpuUrFAszN3kF49PUcRCdCC1IUpOIqdXP.nvjkc9qB0lhv.oqJ_wCt18ymLC3JF57Qfnp.vm7MhpAaVsdsObkCfhTERIMUCoGkaY8nGUiIkQZj1I99q4WDcFrh5i9Is40znBgsIinLt7HlRoMYj8jX9gqaf4x_E6LIx8yd99_MvV9uq_9nGflM3CmD7NzO7FE.aK6_XC44hpEJNGqbZzsF5oTfNYKps6e7JbfY6S3uQ3qHLv63puVZfKhbX99wBnrAIDDSaiV5aEb8tiJOzU6qcZnkv3lf4a7rNWQqCOwsdS2Jr1p6tYFJ_xCmmEw9ykQTZZVHQWB0EZhYzRn8w__BJnKp75ciZvjxXZ7xV_DwJU4fzAS9E0b0HhLcL1JiEqgEHuToltyjr.dIruwNyzvoPDSjsn4BNrDA6SUwcWL_qHUF3ZSQh3sQz9_Y2dGLXuFux4GD5SYaZUegTnpSuxmwW5MhRK97kYWkSE3tEwHYMEvedgYtwvSADBbtgIaDVKTzmo7vZSR5s9Ia77L8Z4Q.NIiiwYFCk3Zo4cBpfKNh4Z.4WdhlATXsXJKPS6LpkzcWy3XjXYk6YPPLUAUbi3xYI81FaKaQNbURN92DO_L99h0bTs7V.__bP16IQEQhW4v2.fmpZZ14COtlFhzJcSbLBlB6EQmWWIaVImy.13VOdvIEDj.CGqx0X35rYGGZ_0Rfx.mTYnnEqWbWkPEgg2JNA7bfGJXd4_XGASkEHmbFRSXNqUB80eGfeU9xlplOs0eJUAgioSlw7Fgoo.x9RblDoiCQc4xJO8jyiF4iTXqmmlNpBJfvGdEfy33R2ozg.76mDp6mI6y5yhXdauRfG6TrNzfBfZVZS_QXRBgvJtdbatKCFNEYODjviyIgQdQScBfWfIld.Iundhl91uxmw89mA6pdF3kYU8b6ATUu7mTG6DpEOBQwjg4efntYvA5m1UEUTFcsuk7T4Eqe5AN02gDV9cQKxNCVJ6fgb53l6XX6vnYaPvSiJN3MbrZRoQVTw512_tN8lnqixg5cBjCud36Um6LjDWpBwy4pERCT8nUCABoSRhDlpCxyKuAzEodBxzqZUP7yr94TTqjKRh3Q1qJus84lEGyLNqZZJMGci6.WNpWA.IruemK4tuJy4DDd9eQv3c2GsjRbt",mdrd: "CVM67Ql64TN.Zm10eP7cw4d_SY0cuLEdRwfgcI4zw0M-1744190669-1.2.1.1-IyEE8nkX1vp9hby7y745M6e7Fsv7RLgoFf1MjEd3KfK1AdLhWzpqJAJdjCWUaxnLlliangXfupSi4ftjpVx5qLIqA_CeWRBybXOxO2b8Ue5e2MMr4Xjd3KVhB_sbCvFHSJyYMCj5GQXpPyQEIsyd.90Qbj5kx9fubHv47q61BM1E9xIodIiD6LNpInW7SBJbXi2CuP0M7NEMDSbdU3MOMqORjW3wYJeusT5B3j.9nDi.evcSpwSwzp1FTCG8TvPYKzdQIGm1XJlzMfsyNI_VyZGaIO0N6b6e.bpSbqQ30BzoxSv2zwn0HYFnmw_5JBAB6DSuItLZbR3VZ0q7YwN4wg4lRN6x8ZBx.B0pin0B.76lncaL6YUhxgmECbTogYaIa2GmLLaJ0Y2BXhI.1mR.jaW_.HAJwh_SjyEjk_WYznLK4H2qyfp50lIUbekzq7nenoqfTkZKyKleNhfdfI4uMs5GF79n_eGHAItdTPHsySU5PUxKVhE4PHwP4SHIKtJGVFinCyjpwiPMyhOoVXwIltXk41PEUtiqIP0noqXoDrByW7I3T5Ow9JMJeL8tjFTtN2gtphElpHrPZAvg69LADm3oJupf4t9YETMx9nUqnKmOenlX2oGDIW5TIPaXKvXgah_ghogBQNnt3x8yLyjKYOYj4SFXQynC2cD7RDG6Hfcn1gSgSZoi3aB9w5FW0rt5wEvbLHBzB85jXdgfOn1FXkI3DWPCaGzJcfwTajFy9q7YPUhpw7LdQlYlqwxl4sr0aso_ZmOPQvVs.dutXy0XBqYgQmfZH4s7qo8B2qJbpxOTJfWmwea3mjI.uMJT8nOpoDk65dObqeEtAO0dYKmNjX7oN6hA0BS6CFB5lj4sTAWYb7UAA6Vfjv5xVibchy2yFTyyoaVeya0gXoiiXxzWgbeyUQyvO6NXJYKcQhrgCPLUzP34jntAXpEqsrxydq22Ug5CW8r9tkMLo6WSnlRbsFtBNFqsYiQ7qaSvkS.t8hIAAx.W3JJ2KaDEQXF33WW3OebKLYemYxAh8j20kj7O6d0jyU6okUkATfHvO0UZzseLY.KH8gNqaHMGdujWWvDQXyhFJUsfmJKYd13zRMYLO2YSAqUtGA.7az1BrB5mnpJa4gYR7m2Uu1cc1.M3dBELttd8eaPnnIMif6RLOIM8aZ66Phcmy5rYOKbgQAXjTPs8OgalbzYfrIYnl2B4P.3M71m407z7CohnsI2_5zzzb92jR.8eQoSWrrV0aYpDXq.ayoFX1ay4DeaIRhhjoXMu8.gbmI2aFxqxslRQprBFM5m1vfsKt0Z.w2eKggn7qGCm7gSEXz8uuG92OSEkLYdoofu1Xzp_Y6KPshxk7awgQGa0abvHLO6pWyjuvOsU9PUnQ2WpTChyIUzqwtbShJPbwV7sJioiuUGb9I3MKN56aD_azSx407HOFWuoKxxGtxkv8smG9.gtanV64yZPFlezB9Mgaxkdip1pIZsnrVgF4ad_LjNS2C2h_fT4OpeIcAV5vydaaVKqnx0knK4BoGCQnBpqmoDqie0R0KLuxArZqafIEEvhUvh1oMT8zs4wa3nx9GspHIgEcfz8NNsn8oW1zGEP8bcpXRJoThhoqvqU8DUsms4IHvhYs.30645qRyD4xgKiZ6ooPpCenQ0fUtqc12RGn5wp0DG3ZukQLrzFz0acEkQW.YqkPLMkcOcfMDdRCGk_DeWPXn1f1Z8JzC5ZcNlbzykGRw1t8gxmOyckXFmmyW1vAnB2k.mbguX2Q3iGLt.CjbjmT0Ur_crs93XyQjwAIJDiAIcGpQ0NEmifbXaO5X2v8ijLMSfQhrgoI7zW6JPrWHEhAkm_a10GNapgmTbxpVQ2b.C3reiGN_3KABHV3KC58mJrK1yOMHRGn7y03R6vXWIRlItDH4VSXLR8DdX_zdHLHcPTq39Xy.wnnG4uIkPzhaHiU_zOzCPoc1GrR4CJorX7pN1AYhnRgrM5u0xoKAm9VW9NCu9v9Pp7ZO_1DB6Q3byJenWnohIahjQNBdAa_aVDGNRz.0ixsXJ4"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=92d8f3a4ce91601a';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, "\/0064.19802?__cf_chl_rt_tk=LkiqD9qC.51zcN66aGvs8x18FnNVpRQAdFtAm9DpkXY-1744190669-1.0.1.1-F4C7qqG_rozcyn0qUWRTJ3quk1.UK57h50ID9ebB6QE" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>