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: '92d74ef43ff6fd39',cH: 'X418uu5x5MZZysFUNKN1HT2f5UeEg0sQ.ZcsmzR5.tk-1744173438-1.2.1.1-W0a8H9cBNVSamFOTIwLSgxwlOMeadxGhhXn6YyDBQ4JwQAW6WhK6aeB4rElplYUP',cUPMDTk: "\/0968.68126?__cf_chl_tk=Iym98HazjM5crOTVarTcvYwhaOJkNivAdinkHAlMg_U-1744173438-1.0.1.1-TBR7LcN39Cj5QIbGI78anL1NDmRxZETeGzsjcpzHajk",cFPWv: 'g',cITimeS: '1744173438',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/0968.68126?__cf_chl_f_tk=Iym98HazjM5crOTVarTcvYwhaOJkNivAdinkHAlMg_U-1744173438-1.0.1.1-TBR7LcN39Cj5QIbGI78anL1NDmRxZETeGzsjcpzHajk",md: "9kQnAo98ehfwbB3mo8LU4Aj7Dhl984fhHhHSLSZEa_E-1744173438-1.2.1.1-m8zSkEAEj36zrm5nN.hEhnIT705bdT8KBYOHuHOywzwdbaSXhiHIy2hQM6J7Clo4Q0TRIywQgrvk_SV.yYUvN1yQ_mRs4fDdG__Mu53rDqUNR8MZPeqaUDmQovTszUUsYlwSDfbBq9cYHVLYMqB27hYvwgVhbLJezBs5PHBZ0nTGvz75v1pARMrcwnxhDs8EhImyOFPKct6YyVFwJXMKbQC0Vwkz4WbilVpT_dUBRggfzFa6xRfzzDCatTQUyvGoPewFORYgLviJ7Yqo.ikEXMefSfa2ha32yj6QvpQ7kJBjCr4osejadVJs2Ps5PlD70AwoIebKKNdymzejzBGtnOfoUP0xzhm.eQ_.nJxZWi6QO3fa1B3oPnehGkX8vrvvwg6UcOQpg5fRvyakGJvfvcUuEzgTc6lP8.av6m3cmJidD_kEqCCA0H1sngeRusy9J7.R9eZu2c1PhFe0WIITPE9F06bNIutdqFpNbQxGJseVDBmoU9NvWzXcnRuXmBDpBFWofx_aXnDpT5jokSrdzIikvXEZi17lFpoJJopiYcIIVC446u8aeJVh2b6ErpV35xZknT3kOoO7c5VkV3oHnOHCxGh5c8_niG80kQp2pWoSR05RlWD9nO4Q7Vlw80ewCBVVE.XRBVmQWHD03Jadj2ms9JleDz_LkqOwF0nJClCZI3LnoH_CO0TNBaWxF6a0pugRn10TdbHGQOgIevBSdPhmFMbinxZqkg5kp_p7umyWI6D12mCKFVHLJgZsaQOOAXjQqgxTmuHM4zBTPZGQ6H7Zdk900DuaJ9r9Oz34JRJRK9C17WeJQPktJ4ZsAm2kv_M1gs6UIOPnf9vr8yqSjgwuuaJAa9z7CSQk3mF_YrD7lUuwLtChgNBKlch4u_F3unUpMqrjhxWeHJzogpDm7ZCqm4P79ZIQGcXENhiO5N219uM58s87yYeRJfvA9NbVwLV2j.mv.JK.k0plKasfc9OyS25dg1cDru1j_tlibwuKhvHb0Q.DbYpjl8syeQ2s5LooTgw3pGEOaNwdhc6t.bzMZNpnWq3T1kYylcU042v6vPg3f11ZTJlbf1DfSkNPyYuE.ytMv3RHoa7MAPurzAEGyQGyNd8cOXnf8cLIaPe1hQ7p6K2sl.K2ZTmKyMbG9oXC3NvPEHw6DNHPzEuv9idXZAVYn9.NI1ctlNC0IhFHcCgugAXVKfuQ8XL2_BtY",mdrd: "VtW2S5iwKW4_3HYvje7RaldoGLUj1BPNh7tTQ_K3.88-1744173438-1.2.1.1-Xpmds5mh8zgX881a2ePJmyCBMcwFJ7wcYNgr6XSM_tUcfEgB1CTGrMjpxOoQQLHyeoDloFz1sZlD.dVAFiqFk8DpuLk.nLdOCW28Xvnrz0_dU8Eq1tFMWMw4uwFh6UVVsjX2QY956ELHdVPrAOkHjuIv2Wxb7xL.hdUJdh7ov5GyoVW4wFSLcnDIDdh_oZJ.kk8SucTnGkgSVjB6MBBSBgKgO4q1eoVgfkoYINct.xtV9N9E.sbL81_s3m3sX899StC6DLw02huFYdciuWB00HomR8IIOd38DtDfQKUP7o0DymKCickx4Jy9YjdS5K1upE84Z2dDuSeesGfSDsiuLVkmcIhYDM6PYNQT__.2LE3etgyj0FXKowUkv0bPkUShIeM3eZG8OrORve8buRIwy3a1xSwYzmz37G6QhQZSbcKX9BK2RKYrIy6lTaWzBhFc0oFsUdDvYNHrHpk.jGPpWrf.Ajh5l2oRyR7dZYL9BZwdiDXTQF4aw67gopj0ji19sxbtsmvum4NxH18TaCkAvObuQg3ML15r61tIvH033nOxEobbK8tQ7pVBRiNQtqFT5BNa.heG3jsz3hnfdWRrNOVYbhFyCQLCrke0Bl4tWS11qAgVE1U_t5A6cRxzOEANNvIavHebqa_LjtwuOTYRdtcyLESU8yQ8x6aMVnL1IsefTMpFRcAME6PVm9N36h260nhHx3CwEV9UA5AEUEjXrnUy90.nqZJL0TDBqzJXK5D3Rxi0J5F5CAYZYsGYSjEkwVh44cNwI2EMuKDc.AtXenl5hAXRXgj7Z7a1Oe0uZXTHm1OQLK7mekVnlViy8TJxpEdpl.8yzl1IHn727dwKEKJo5WzpOfndgnM_lttqBHu770W7pDXO8rSOW_jmHU4NSRbe8DiAWQS5anNzilbDp1CPQ4M6jwxnIrTIlp_71F21.WFehexYbP9mIDB_LmN0a2tVqPAlMlIgCTcteQ71wMH624lIBx1EeBDn26HV7xFHfImC_jrAOXzrPWBIbVtzKI09IygdsbEblADsz7S.yvMi3xw8DpfPkRhEZgoNijrwjuuBhZwsf5GwCCxeTf0re4cQYNi24c0diA_ecj6lH72gFouEaAuC9SuOmYaEXE1m28Y_oHtu3j1kDEIab4R5EcmI8DM71x89.2.BJlKetVwa.F5YmouusAh9I0e34PLwazBscTV5ZodpRCxWL.S8QMzQr1mPom9AijvISFr.FW8jSFcXyCNfmnechCjaZ9dfi3i70e5PcivxqfFrQcnF0dQd1avdQ4FKtT_k2Ao_H0xIcIdcFE_v8wCVgl11ES8Rq5QBdnMLs_PxOBQFCeWFPXQd__sQwUw5p9wIu7OMgeQUUXgP9FXA6YpL1IjYCr3Sx_1TVxw.sfAKw37j6voPAvOmp1RLo5ayKevotbLYcw_nbdaolcAMlqmr1d6lZO0QvLx9Wh2EyeqAySAQlAnds.XbyiwuT21n4d5j7CPC54Fsl.NUOD4PhtyHD6bIhFxcJd2kUAISnDAK1fnGjR9JWBFkScjP_j5VKXRgVSZgHLU0JR92zPTJlkDNGIjxJAEBBuA__NQ5Aq_mTGCfX6kqhcy.hSW6enO2cRv9gV.JALWhXu153Gau0yPpdm3tLbkl6qgTH986tuaV0Q4UJaj23lcycRehf1dI.C_ozyzw4mPKImhiuZbn4q1jkyWBeiyK9ZGgp2XEGM1IsvnXUft6PMTVulHf20Mrmx15tGD.VPadRQjuXXg73p7YYDCWqV6RBy.O9Zc2Ms71VJEu4WqMDeqTJdo0bFXS0fvUxgiwLH_jOsbKVO_Oqq_nnykuhXC6Xg7WbANXsSL0lyCrPzjTNXCxhfV_vZXNL4vTI8dgmfmm.hvZ0xt2n0JII2hqemYl6JifEuZldbgVWc3SZx0dQWs2cOpisOSYgJpyEr_UYz4vcDe_EBF3hwc3ftIPFzGbtXoowf3Nzso2hscnLeSDwpeCRFZu48aO.SEMqM6MS8uA2jst2XM8DL8sY_O8es1zXRP9GKP7mnMHeImSpUtZ"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=92d74ef43ff6fd39';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, "\/0968.68126?__cf_chl_rt_tk=Iym98HazjM5crOTVarTcvYwhaOJkNivAdinkHAlMg_U-1744173438-1.0.1.1-TBR7LcN39Cj5QIbGI78anL1NDmRxZETeGzsjcpzHajk" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>