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: '92d9e68bdfdd6003',cH: 'CmdznSupQHzqBsjZLaZqkbewh7PtsxeEZj2vhwvx4wY-1744200618-1.2.1.1-KjRS_XJVTYgDmPH7dMyEw2cR88ukdLFuBmHoriVaVCHqNlL10xjsuPt5aqBwfaUn',cUPMDTk: "\/serials\/63?__cf_chl_tk=fBlLZa306pFk41Q9bW7DG7VacW45H0EnGPqrleVcpYs-1744200618-1.0.1.1-Dj9qHAm2lnPdqKEmDv74bbgR6Tj_nIaNiFLVAPJxoqg",cFPWv: 'g',cITimeS: '1744200618',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/serials\/63?__cf_chl_f_tk=fBlLZa306pFk41Q9bW7DG7VacW45H0EnGPqrleVcpYs-1744200618-1.0.1.1-Dj9qHAm2lnPdqKEmDv74bbgR6Tj_nIaNiFLVAPJxoqg",md: "I5if9_A0gSnxdgQ12RGSt8z8DOimuGOVZ5frEbl8Ze8-1744200618-1.2.1.1-n39GjMmAcZ.wOmJcGyBO3jIfFZrFuaqx7ua1mYRR_1LlOrkuCCze560Xm8DgqasX5nqVRGyasPcUNYfI6e26Mo_nRjKPCSN4oQa6RURBd.41okACGLx4oA6a8iL.LMfl1c3cLRL.KLi4YELL9oQbGbBU3FGhC3QzX3n.FK7GLPo2h6711CWdIH0y6DMBSUBqfP6IdhIAr5MaMPQzonIaF4DgZ151AEw9OgwXlsRMb4t5FVBJZ.h5uWX_AMLCGTRO5vqDE5zt.9L5Jy.n6cYasEDwqLEnchyRmXLkJraoPtoNC.NmAhRLxSmSI0_1wjtalM5Pz_tVWv9tqQ_TbRrlmCTA6ZNXypARPOYI4.k5HFG7tTxXEgc6MlhQ9NeeM4i30vOYbEq6S8a74d6jhnmydoOo3rjwVJdqo48qt5dg5SoZZEYVLILBMjmESd0aY7SyF1ZtIrX1n83uSHiKC0TG2pe9Wsayy0eo.5CXdr3oqL4RLvvQU.gPdAPmPfoD8A359xPbKS3.5iWngreZZZfTmG0QU2HBSj1WbYUIcq54cnqMSNcYCAK.A.ka.xYDWP4NCIvczhvnmJjnq_3_zMxuX4.01UUFK0nIId4na46K.g8AIDLpKa8GgvB3ueIZ1Sjh6jBRj27y.5askIe4CrwvBxDbbiZ6p59K.ztosmp.WK.61eUj0ZSTtSqX2zpWOZ.nXOd2C0n2EcuHGXCK7AjZ4Y3BIvjSgBN2nh9qqG..fW0lRf7alIH.4YYlGBmIc_pUALtxcDG7xPkCRi86aFBnanXNy1DsjcJHYclizirzLHQ4retoTJ27v.uLlD9f9yvckPc7vRwx5Qr3pQE.aFABpt.udtzOdiWxUy3lA_4n8aGQDZt224Xmp4crBoe9._S9NYZ.mlbpHdwC.._jpdUpF9mibg278HVy2HsB6bTdFbDHg2q71Bt9l0mBPyC.Uu1ss4tltos7bPShtcUSDVa7gq4MODy58X2Sc5aiwNFWW0Tt1bimEirI.nrebVuiCvZNpF_c77bNLWXMM_B61Cum3lYO.JI7fxqzlQWyF.PUIeXhd7un3iF2KywlzXoVzjocRto0WoB_pDVgrhk4P.q8wj9bD7BFaFScq4WJZQGEbAlwm41frySBTWOKjK.cvXQX.2JzIdX1TE7nZuepcLjemtm.sF4RqJU.M99GWHKwtjm.deYCS6Pq4infOi6vdiWT",mdrd: "BG2_1S9q_1._8x6O24jYCY1uA3wkx61hC2eu6kCK_zY-1744200618-1.2.1.1-qIQdukKDA_oO5E_WNg8r1Ml3g3F1us6H9pUivI5fOEsjmJRWUPLXv5NmxdGTd9d7YycuELvdV9s54sVKRQW4DWsKREZlHQ0gDJofDN8HWnn7zUQLxiZZSuxCBKeN60t4zq8L3OIZktDgwU7.k4CzxzlvTgdwlO5FnSPteZoYn9GSmlZZXQGNtyFxQsfUi_s8E584CQxwverR5bUytY53Rg32B8hYKaSXGM5kmQ5k.fXbbn23CV4nxDQWAMLUDj6DBe3vA8R_9QgornPZBnvRu3s0oqUHO.nM_QBj1VtBURKeczSLg7euASJ7DKNAKH_1SQEe7XsJYUT.SJ91rumtjh8yVqv69ROmRwXYa0L3ywM118.I635J0EGKR6cJ92Q7EYOkhh_Tnf6YgpMFmh.be6fVOGzgMx5C72zs7UvmyXMYZVzKkahiIUfbPKwIeWcC6M_GoSIYZUTBHwZimMmHNJWM9G0jUbNyOumQBxKvozrYj3YwV_XJ8jOELmAO5zgqEViK8KsOKvPYHNRncjZDUd7N3r5alqtLJmYDRUVS8gAM2DZZ59A.NWKvMCS5nnaC8Tg4N4POWpI4KsYaPl0wL5kaRQYfH5YY4_dNGKraeliL.9dFivDzU9QRrJT22LGApt4T_Zg2oElr8txWoKwa3PEGOvmZXjKAz0EhDbD2VHNuRcmL1R2EoF2f8_8AO78IJaGoPNNBSwp_Z4aTJxc85o56YkKle9yddH2zKeJico_oowAXO1Wb.JUTyZVEsDfg4d0qQSS5_iehhcWNj4Lf.DOlNJQGkvWAaROs4dlmp9AA1zXK3_x6saB1J4UeNGYz3Ttl3L62PIfNjDLwFANlfkHfTfVQh3.8aXY2DFA3zCd9lsuh2FNrg9f2RfFm2k6qXD3NZSCYW2m3QRrf21VQEbNDYV8EUX1PnV0aMP6F_nGdjPL5xlSScPeHzDPxPwO_ZWj2NabUrim_Cj_Imlzm4wR_EknDaLY_gTFYkFTcGImQawfRxJ0CilAv.H6rRfnfuN_ojJjKO188j8Pc4AGX0HkjzL9ZdhSyopNMRN6.hHqOYsWIKhp2YKmhSLCacStwyhsZd6OWiTJtsIgAsQf691u3ETrwTwrLE85ncyxvcpeGPdR97345TUHJCu3btWW.7gC.6jWYOhu8SEi79Mk8a5Pz15BzEgpZczViVQBE30gogpMvsAYSCWY1e6vkEtfaq859bKnA1mK5rfWUbeT71eFMGSC23xjW0P.GrlFu.k9n0AYwZeeYuh_o7XHyutffmDBDjBvvvU_Nxsh0mkL4EfzsXXv6eDq2sEQ5EFK1tL6ojXHCkz4W3QGZ_a5ZrnMjfkAXVy3xldSoSHtQIH3jH07ON_SOdmjktIH_o_g0UEOweoCTUYkuGBuybx6rIFdg2XZ6KxlB81.JkTc6siIRt.r_vezjhDFtozG5cMqqM64uZC42LyOdYloFxIbRk0sOyRg0z3e8u0FltJr7pegKLq7Mf7gtxL_m7Gn4EsDAQLWNkZYLFHqhl4A4TiJEJZYU8Q0XaeEpqHkcTUoIdXbYHG6sz4h0EZz1jM3yVHcHZoXLpo7SndJQNzEyE2bQcwebpDegRhPyzuzjxneMpurnOU2WFOw828ajRmBOM74Ly7iOSZLZyK3FNVru1uuZrrFkEbOSNVKOseHS1upvDuDLbYW9Xh146o3DXyvbT0Kgfn88eKOW4S69re4SkH1UW2XgdCmT3ItUoR7UPjQULG32lNrT.2TKz2uQEABmaDWy9xj0I3DEqbwq9bpUEvxcrwGXYF3usY.dQMjAlNL7rmJTUqtynaK7wEBb2c12coHb0ZWrskw0egiYua1a_9xjZerVmlZLIGE_eYXYQfgNkWuGT_3Y6l8vWavqYy6mQ_mNynRiC1trNsF4xqmOKFlzxTtlftjfb8PeicqDXJFR_Yc8txqPrYn9VDbm8ADsyaAqb4oeR.hVIEOAL.5NB35sPSsD42unoThn98L5olsZD1rx4f7r9TUNA1aXwoaN75c3uPm9BPfI47wR3VYrhREPNGu0"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=92d9e68bdfdd6003';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, "\/serials\/63?__cf_chl_rt_tk=fBlLZa306pFk41Q9bW7DG7VacW45H0EnGPqrleVcpYs-1744200618-1.0.1.1-Dj9qHAm2lnPdqKEmDv74bbgR6Tj_nIaNiFLVAPJxoqg" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>