CINXE.COM

<!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: '92e4a6aa9821a459',cH: 'oG.1QJLgTJP47NLZMXlAi9NS4dZ0ucTlNZbNx_HlSBo-1744313345-1.2.1.1-U7uR72f7kai8e2DLvGBDmehstVxkkGapSMgyjHsUi2G5prdoABj9PVtlMRkrXwzR',cUPMDTk: "\/0603.28010?__cf_chl_tk=13l9_XY09ddPGClCF1lyhuwUHNGbft8rEtI.n8tCTBc-1744313345-1.0.1.1-5IVQS.jR7pWqL280agmhzptImWqqzDgwRoC.FoVkXPs",cFPWv: 'b',cITimeS: '1744313345',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/0603.28010?__cf_chl_f_tk=13l9_XY09ddPGClCF1lyhuwUHNGbft8rEtI.n8tCTBc-1744313345-1.0.1.1-5IVQS.jR7pWqL280agmhzptImWqqzDgwRoC.FoVkXPs",md: "3RXdnlbIeVN4SO1ALOcnwK4w.MnJAZr9Dd_FGyo0goA-1744313345-1.2.1.1-MGODztVCX.Cv561fp5pUGu.4G7I6fiyO70QFCAgwuV82ZB2T98Z0vBmtWSYZb0eILPgaFngQKzgQwmGVi3.v1RBlKEvPEMNlHJ.yFVSRF4vfTe4M.NdAOww84BX6_65lYx.6z8DB_Kjkk3N5RQKgZnVBS21oa4FJve0wByniM6AsINwJ_d4Ld5DITWtRSdflihaB9aEAMmdYVe5f.uJpD6HapiPZ2I1MYuM6MPXHX6x6wnYOJmjTBo3eMh6ZqfUBWZmuTDdjOH2ENs7M_GkY1xQnX99RUDbnThx02vu_lFxENT.Jq5KFrEvVEHubp063UFQne4OuIkSJsIi35WyqRgw8vFM6tOusNX25ful0eHqN.u4HqBI5vcof2_i_5UKXyNQAnS1U0kiLPyjcOw3yHgwSG5tnKEjAV88KvrbUrGy8zrEjYVzwxuqzPzXP_TOCLAzZ99hM9mKsK_ok.qDwei892VWovEENmOuOSg_.pNqilZNYTxLPZNwDShZmeZawWT6hwjP0le0GyWBM_IHv8ea6OKWDhvNOLJ25.i4rY4w6tIYoxJQhf4LPz6S_E0KcRO5xpxmH5V0NyJ3FLtVJX5tFWwYOQxwfDcbarhHPY_FPP9TXRWHH52ZJxe7lIF7UKXPachM7ZvVbRLIpi5xXQGJ__4JbHSKnqv6Z85hk3j5A90GMYGtR7qjFtszJ9AlHruyfy.a1ISfSFO19KaXiwXVPh9TqEi4kOqbniJQZB7kLseSAPz.lxEZvtOW2.u__ZgciIA8AZlIfKFTTvKT.w2A17e8kdwJ8zRP3ZeWy7VXCC5FeGafCPTGG1kOacdUbPnhFyIzFJWwrVmKVUS1MAAZH2YM9z0b1IMufH3qBH13I4OSQamdXukn5JAc9FbaOPtmk3eHdyLryBHwyVnBhqJ5qpv.4I04mAqqBZJmAf_XdZOhjM7_cZLIBd.oEkQFSs6NmPeJyAYwOA0wRvumJs8r8EaXcZCppGC1UE8sxuKMZqLrdaZGCb3VMD7mTj2OjTX6iPXe_62H_F5vIT4ou_0f9CL1cHLZnZqiTNJxaoOK6VteT1CyB5nGd2rhlej.FvwJrdRz4s0LXIUJFe06NTVp9fbOCQtIx9kU0O55gVgGJtvj35dnSsGXAjpeToBkDmBXzvU2d_skckWhjcGaiBSi_eD5a9ttSihPtKYu85COQjBlgsNDQxatCPrGIkuJs",mdrd: "E9ShiRBBQ0P003rjrAYaAcphUFwezNhywgGuItp1.wM-1744313345-1.2.1.1-5j_kv9fHdmY6MIhvePJflK1OScRtGVCzlqBHYxfXAREDCmKxPddeRtYcv.bq58L8EVqfnGd_CxIiYKV0CuM7IRt8keVhKDRELmCoDx3MGGH90111O9AJ3dnNBs.YDgUf0JoyebPP9PdbwSofE_TCTmbUmXTLSSDKR2IpIvY_ONBoU4nLDTdXmduEV.4SGHDIPLuIG5eHBV0FCVDQKhzLwvoPB2U8S_ZP8.w1lE3oCCBzhiUynhlcqVFEtu_7aUW32lFMQtAdFP6u2aLgfXHWw3lM3q.XxVmFHOiFEGShtjYESL1pf8Ns_ezk1MLGN1WjtG_.p0YDasEtMQhiZ3GI.OmLfqYTtIcJxegK1WEArBTfe8a33qdBccLh1slpr.u1Vb2FyR0EZwpKh9FPye_ZJK2sStAbdnzpO6R2tzAnPHYwRn5RUigQP0jCloKknuYw52H8U0_Ykw.UELXS9FWP4LdvoAJD2DRPigYUw6yO2BUqDxg_YeYdS2RpRuXnVTIX1ekKSPbeROyEdsz4GxZfOiFeJupAY29A7WVEU1bnYbMEwQkKJNnuPHmKcMm8GWt1neM3smMKBr7Ekuz2Y.dPZXMQ.16JegynxAVrhmemt7_FIdmFGqcSCyloPVyhtv5.lCEIy6kpgudu3aBDl_P6_iUBQRErbcSgPXwQYU6OO741jXRcbS88j8aN5GNfu3vldBVUX4n8CjaESg8rIm7FljxD7iABzcyBG.Yi.OZhgFj2Omo4.CAGFLSNHaHmGzC0qp6F3syKqsKpZGp3DlE7kE2xng14hZbv6vjjgvjhKqtJhkhNDSYBk1whCVicVO.2doRJNI0VnAY3RKcCFtEFDIEOP.zExYiA2KO927eHoDWZ5PE.Kk1_EwV5jFQI65N3Tzb1uVDqFBLIkExQxST0AaylcRqUa63ktFRkgXe8am8bXBHYnLYVthCx1YuKLu973TwyLxDOoVkS1qcOtgfT1oLf03m0xupkbW0SHcICu0C9RZvTPWPn6Yd6NPVFWB2Q4oJxeT3unOkD_mMYDtgJe490yTDheki.JpsOKWkNkvocQB_Gnk9iqal.qaXhPgG0PWD1bm09sBpmV8Gx501zRSY8lrF9PVnboctw8vaUllYWxd8L6gNyS7qdMD3dBQgLAcWu62o55eNovgOkWT1cs4IGhiofWdaeufEiEsf2rhcS2wYJ3eqXQGcJa8MRiGDUe_Byx171f7FcCI9yjnCHXbsUIXQnIHR1MyPXfqnGsABglaQsBAY1IDUrTPxnytBLZ.kvHMk67kHwNih1TLG3SxF8WA_1.i0ZOVfD3gVWPQ2Zis3FWIRxJHWVX_Gc6I9GJAt6HmgFfTe7n90QfJpuwdvzbgiGnZIPmdjKCaXcHjHrGnM1cqhhP7CbH.xSZiBc4vrZ0CZT5J2nPGcqvQCGQx1m1j51x7kSHms3OiyJj5NmZGWnradZyszPPuNZ3J4Aq8bfuuq38mAwWLzlFBh.b9WqQPcmHnw8J9hG4QJUfDD.jMSqkGIYVbcKvxHEU.fC9MZ9cvXCtFSagvs2b9cJd3BKWyWaXy31hPAEPdqmjcIoH3ens5DuBMz_TiSbZLTtnpf9BYyFt7GVzRnp2Yy6fF5kM05xzO9Ai8MMrsjo5EbYZoThSulhj.9BN.tnrnMjACesmw65gF_wuIJTsH68pfyckrbBpNkzaDov1FcLP1yFTCrdIc69nSyZs7ZmgythA2p8ibKo5j16KQPs3gMCCEEqJxb4KvucgwMCKm2bVPoZb2C8KRA8szYbc.RbptOuuhYuv8alwt8Y2BfrHHkAMUSGDHyWcpT17w3YAj5bSZHhG8JprEi0S3mlePnApTIw7VqmC9K0t5wIiwGeG4Ij4Q5x5pVsg6vkyRivuarEyg2TGAltesEvEpPGbuQ3dFIANWd7f4t_fbEM7yxjFgTkCTl0swXPW4fuBQa0g9T_.wEA_OUoIu80I7PJObLPb88T2Um0h_FxGWmwI1saPhfNJs0QuvTUMJaUCpKgl5xZfhxEAWlp4xEH40fy7UgchDG0GcyN307mlzzFD26c4b2_hA"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=92e4a6aa9821a459';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, "\/0603.28010?__cf_chl_rt_tk=13l9_XY09ddPGClCF1lyhuwUHNGbft8rEtI.n8tCTBc-1744313345-1.0.1.1-5IVQS.jR7pWqL280agmhzptImWqqzDgwRoC.FoVkXPs" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>