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: '92e51b126c0e7d87',cH: '.1sfjwN1vCVlihLJK2fsvbOi1Y0DGPlHB2vQMEChdUY-1744318113-1.2.1.1-QEOY1CExOIIapMUjrl8SaWjWlqzE0JheK5QbzOeDffDdq9OmZXlz92otK5ywgwjY',cUPMDTk: "\/0731.65049?__cf_chl_tk=BTYthjROTiU.qtnKBPOdkvmqBh8nSkyftEH.t.3N1wM-1744318113-1.0.1.1-oN_vArbtDI5RPL7C.8OD6zhNzzCLhjdXU1d0b9HIVME",cFPWv: 'b',cITimeS: '1744318113',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/0731.65049?__cf_chl_f_tk=BTYthjROTiU.qtnKBPOdkvmqBh8nSkyftEH.t.3N1wM-1744318113-1.0.1.1-oN_vArbtDI5RPL7C.8OD6zhNzzCLhjdXU1d0b9HIVME",md: "B6pJbwBLPnLR03Kuq9zrUF8ZzhmAXza9bVZ1LKhn3sk-1744318113-1.2.1.1-wA4gMukseNwOTqQkOIsH3LXSn6e64ZWKMFWtOdvsGIdf6xgy4O32h2g8UvN4xr.RJYGoH_r9Quu_xiE3v1et0eQJ4SKvN9hMDR60NJ0FWfdmJhrn81iK5V__ezmChykTtu2O5Bpr7sfDnNvqQI1ZaxgCRVSC.DNkQWDO7oMI0fyE3aIojgebqi9zjGmc7_l1IlpUwwIT.yCZFmme_BSz1EA1HxQMkrif41HZbo_yLSbuSVqs4lBkXFugu0nuhJPsXhX9wvzWPmugFe7U1bEGHf.HeiEYJPFWen6jTUz5ou0kf3X1SVckH4n8Fm2GPTrXwq9LtV9lecVic19KYHriILadW4SNdxus0TOvjrKr1XROAUfoQmFrHxUsnJwB8RnAlH9WA0r1RvGepfvX2YEGbdCmm1e5KtUTdX.XpP281WqwObtp4TN8L0ueVrcq1a8GbLbkr1WEgMp5uzgkx_rXM0rO9pEK_wwuGGMEgcrLoDmeSszKm2cs2unhOQ2FevI.BqBS3kabUvxaN11KSWsOkj6pgWxVrv85.SlEiyqf.PAAPkDedloCPQ0jqmC89zvdTMcrVEhM9hxRMGUSnseV3_o4j6OpboyO_GssOF6l10N2L6zghasi.d.JA7VnyWk4_sp4d91uL6OjcYV9dy_IUbElaiiQ3NEv8_nMy30m7Elw3SRraNMEdw5cKjc3dQilkktB8xELmPKu6gXEnOWe7elprsRNAjeaABkOa2VvkUV22IewG3MxtFyKgb2GnDTCeeeyjB07eeY2H1sPdhedt4u2phz1C035BZjXnaj0i1af743x72KtCIh1vXhB6bHfRUjz.Hz4bP3sGScHl_UIOaglrkT_VA5w5aNC2_MCZJyPtPTCAT85MQOECn_b5CGtE_PkywzqFmyjGpN9tV7sOqnOjP1WC.aQYDxiI5TvHr2_Lrv6Gt2vOFmEVmay2oYE87.gXO.xSk32F86bOg_T_3.Z5Lx7HdXL6BI8OpJWZewx4u1hl0.VjG2TwjjWegQvq8klgq2TBVZ3eJsQczAO95ogvHWvG6F6COSSRD1AFr2wLC1Q1PDtsiPIhNy.QesuekuJOWhB6dvmSVnQi76nQDgIMfrjzmJhbvtcXVuqrbHn3TVBvRE6SeN35AHYFEfa5bSVtjzjBs9crXl0sx4Y07s.Dq_wYNWvGhOaWFGK9rgslRN_S6LCNSCSCqKAiau0",mdrd: "lDw4XVEpBuDziSKEClvRxFm2h0XSjyYXatk9BxvtKCM-1744318113-1.2.1.1-2NgqjuidyeYNanykyszQsrwKOuwtj5yRqs3LLwzJ8yHvFlgjQooiVYgn1m2K2BUKyTeh19OOn8gmJOOK0kqgcHx8XXrKxzgOcYtrHyBCPjmY1Y0W__JpXaCFNrN_8TJawC1a4BIlYfrjhnPn8YLR8m5xWhd6ZpdqjFu4xxQlc12KukEs_QLa1WGKBlCIdvnLD2LvC2WwbOBVUmiJ4snug57QX0e5.ysdc18DeCKOB15Bhg871frsnjSSsHXsJ9O5lWOcIIH6rXbe.oX5CaXnvY3.RKXjGSPvnaw8RLb19HnXTm9KexT5S6n1o8Ecx.kwUzfjIMMOMY0HG3.pt4LdfxHkxzLpBnh74bKfI0elp.LMGOKIjlZ2NgZgwxr6oZ.k0humwzFA2yea55cfXaVvx4AfHsFfFgDDCuYKgN5LQ2gQKJbImM0a6jMIYsW5X9tzoxD1RPoiNQiGklA2N0nXKVGy7qfBw6Yymte2zkM9hKhokiqS5hM8vPnI4WycwrVS44jeUDMu3ijkztN1IzvcW8HhwR.x9zZecG7ubAPkm_IPrpOMDsQwH9VP9EfqNVecP5aVxgnnJjDgZOaiq7M4QeNqm1QM444qDW4zt3Ll4crJA8FZXBGnu4u524VeTQt265INXEs4onAYXYUupZWfoszzlQIYuw5yuALJsPGi02Snqblg6R9Z5Ua2QTRMa8rW1Qem0_QT49wok3ehnBfHT9PDU006xQVw6.DcVJheUwNGgLnsxnPBFGHgqilQW2zOawLJdpxwty1PrNOZCBqHG66qxkd1OZ5mmvvx9k4x4c1iZsJQJ5NllGiWlzpyEPZaDuiGlfmLu4iwF04fH4CA6sudJTgd75fugm_qmF3CZKHZsVt0RUKMsVpR2v7cSodHu6RD.Uraze45JYxOieSJr4YBflW8Z3ZGabUbUQ1t0BSSJywCRPZ4M.sCF3JFWQxFLlbVb5Uq47gBlfTcvFzNFvr4H1h4m398bFH6Ppnfi__8SA.UzjImmTbphPa2mM0p9nGTkR_bweZVvVRtHZI7oK4Uh4OlJMTESidffyN61o3Mm4PHAs9kewsBC8CVtj1rlS9PToIcXaNpH.dWeYAmH0IZTcDE1JgvDb8PcQOqJmJQvXlW7cMvU5WmbNBL0OTMnpeXVsp3M..5mFdVDpvYufbQ.X8YwpRQFTpt9ZZ6SVevZhhuE.jZVIu_Nox8n9GmgnXSapsqCob0B0K7gDU4hEl.HxsT0S82.kPruQ.aop255IQcY68sJW8HjRVtrVLY96Q6LilRi2lIkH0v83.frpfDz6Y.vZ2WVcssG9TAfHEiI6DlEoQLQspBKJtukRnwrCWK4rbpeyefSkW0yFWl1tjxWfjsikkQwvLpCNvMgNUJrI.F7Gm1hNSYDva2sHgpMQVxLnB_9vt.oPu93kJhm50o0IqP4Ncqc8tJLbPQFQ.AvffNUxXsbsfggzy6ftQ7u0uWSuj11DCR9WIE3NcYc4GLfCvbi0puAJMAkSKImwKfqx4_TcQ33rI3ry3IvOfvMcPQCUXIqQgGBOvcFwvaTDWVoARdSXXy.Fw0ls1nCGWorKuXh4ik9CxOb0ERc9q_47E6VJ3.QQRAPp2SRaWL.CA47H39n8YSGHXdcbmAYSLyJSYqAqgIT0RxWzdZKs8Wo_kRyf7V_rWdk2coRE0SHIJBbOmZler_wHeBWhi4h5cbv1XQERZ5gFTJsf6eiUDfmxPqLbAFJ4BaMAmt0uKvFvCJDr1DMVUnStn6pnDeiwxMV6EoY3Mkx7dHFTvOKw1btJH8Gtq5GdK04DyLyd_JiItwCPU2sKAB7i3LU0fyxuhQRBoa96jNAPR26.uFln03HjqqWGdcJcHov2mMmbE1Fk4TnqrCQpqv1Oo3PA5Qkyp.EjJDPV1PewJ0O8yyTn6e31RXU0L1NqdNna.FTypo5aLSSZJ_REym2SPdD8pRyq.a2iBuvyahTGmSGeAtnJkZH9Jtr4UbXPNOA6DvC_BizldZJiMcO8JAsBqpF2OxXyZe1nvQV6a1FGVTm3w.yJizV5HpUgjN2jHtDlS2A9w9Fw"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=92e51b126c0e7d87';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, "\/0731.65049?__cf_chl_rt_tk=BTYthjROTiU.qtnKBPOdkvmqBh8nSkyftEH.t.3N1wM-1744318113-1.0.1.1-oN_vArbtDI5RPL7C.8OD6zhNzzCLhjdXU1d0b9HIVME" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>