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: '92d5417aefc4448f',cH: 'Tdka7qbrqPCn4D.1Gf.lNpHE5Mz3BdfvIAh0ryeBdWs-1744151914-1.2.1.1-gndGGSUMeHbVcyKmO4fwQLGdMYEp.4FIihxAv6Ky704CQ9ptMyQzT8IKbvVjabhL',cUPMDTk: "\/?q=in%3A479216&__cf_chl_tk=2oa1e6Cf4SWfUJ6q6MO1D2pwkQX31Cn1T.OCF2ho6_A-1744151914-1.0.1.1-MozhoUtrRXzclEo7Kc5rYUmcLunRuvwD1XGyVaernvE",cFPWv: 'g',cITimeS: '1744151914',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/?q=in%3A479216&__cf_chl_f_tk=2oa1e6Cf4SWfUJ6q6MO1D2pwkQX31Cn1T.OCF2ho6_A-1744151914-1.0.1.1-MozhoUtrRXzclEo7Kc5rYUmcLunRuvwD1XGyVaernvE",md: "k_u5bAZcMz_LCkQeQz8s4SDcdthHpCajVI8S_SQtbog-1744151914-1.2.1.1-4zc.qpKiz.FnuEDSYSc38IhMF.zEHXmTTcQjM7ZofAq_RKsvnZC3CF9k9HJLgrumrwRi78K.sgFNMidjtU590YLroyCQ8rppv3iu7RkaDAIGl..Z_KcMDrimmk1xxfSoVeXgfCwU8pZpx9UUe5mk.P0j0rVhbsT9WJykX_3fcJFyriiVwI0CGi5sKn_GGy1EpspzS_zgMsSLLwYE9AaOXFvgudC1hQVr2hAgsobbYpCbDjCOxbClrQh4x4EP_tYxa7Okk4IoqFSyKYmx0sESNMIlVgBC_tYnlsL0mkY51mZRMKceLJB.RSWiyOtBYfo8DXLAJogLvpftEdqPPIwDV7rZmM5tSgcwm_ftuszIVe6.dR40RtIoFrJT5d5yOX10fKffUsJZgW5dSw5QkxHBauTy_sfwU8bZMONg8.QBeYCY3vp98RHTsSA.7QItlls1vTNNI9c9IKzruA.u2uijjX_XHkITuIJKa1owu1zwtAm292hqoosNDOzVQJRvOPpTkhQGzkjOTF9GeNNbyYCTHfG.Ya_KPPKJ.ss_eSztO_7VWBuAW5j2_GeMN_1Cyev_128VTqqwXYDwbbndgaMeqK01832iQilXiuucRCtvtGxIn8JdEgpASWM7fa7lMEsuEKdD5aaWu0ICe9VrHnOThd9SgqckhNZwdp3t0VHq2MHbfwZw1CX1MWn2fkrzYJ0dCIrh4fBfAeP99mBHj75WTQ0S4LCZnw_u3vfPAfAP8RFVEyzydiw5VEsKAj.ldZbuyPkODZsW_UvgkQx1bucGRtMnGXO2IzIzPXCLI5Mc1zwuYLkOhxD8o8L0eOvhAOsqlK4QXoG_oBvovfwt1InkwvCsxbkOJeiX_.VEw6kyJUOUEg0oMPd3aqM5jETV8JyicJq9qfA.2K1mAQU2lXy0Lx9NcPdk6TrF43P0hUitWegFXU0oD0QagDKjvFYGn9xAQGTXYa8IpkmVOzuMvBmelm7Zwz6xZeOV.72W8rCRyL688K2mWMXilQCIHQWoy9rs7J9F8qL14NN7rikpUb.US7y356EvRm4U5X1OK1usjqZY38GBro5D.YQ0tydTUnxlDLgx93PnoUy4SxH8J3UrMU7WJ7VpeTMkjnACjZWF23VEk_4CU9Zvr3Q_GZFcndAyNes7qNW7BpjMmY9guPvdw_ekbX1dpoK_YFKgC3YHi.B6bnM61UwNP_UlW54broAF",mdrd: "9.tRuXFOd4r2ke7bSO_2YtrWEoy02cbO8oe3K9zex30-1744151914-1.2.1.1-XYvuWxsPgq6qDuvgO3lIsG3CrA9N_mU.CW0s0uc7rxwFX83OnmkeL_kdpY6G1HwZZH2R0GqqksbRqQpogAwYzBRRqPMChDxvWdgoBULczmUc5FmAAe2VQLlfeeDc3TjHyEPOfncphN2RCoOXdLpus0_vt1NjbFoN0lnutFPyL3gmWX0Ht576X3ZXIXo8AwKIQK.Ob.7enOc4TtN5PiLM4.tp74.LsrQeEFCj1IpkUowQq4E6hm7YfIJKC8dl8yVHgF19sUQGvFauX4BD54TzIAw9LJg.bL9YtdxjC7HLjCYZEpw7mj8kEQB8Ygaa6yp7qVd295GpRh2hHzCagAympNYR4.9LoYtlx74PPnEx3pHUCvLj8QQB1mWzaaxViQXHICh.Nr7j8ingGkbcM.2681U9iABVwXR__xqDFo68N3yxSymT5URCPRF8rEghOrWbqEE9Ycn5kGQFsmyvUNoyI0KvkLJ97DkMzXVgbnCKY43yjmXX3ZmibMyHGWsDZ2zcp3JTA_OYtuaykuE9kGs2P3ZmUhBBI.zK_Px1qrU2m3ITPRCcPvgbteA6w_T08FT4.Hi9ngXeipKis_bgZ7KktBQIrlJU6w_VydDdez1I0Al_71EiR.Z2DEDJShRno8paqzgBceGdi.J_tqIokwjm.bMSDZgal3WaBuZaT4eaQOhYSWClC0y1.trBhuT9.LIO3ONVI8ZNRQEjWajOfQJwZ8LZPXmPPoGDJGoWPNpDATN.TP4oDiRZjRdMVHPoYhnTml63m3WJ67JFyOg3m6MCzf2nT_ozaasHrgN1Pgc9aWg_225LHlQm0kG_u_KU.noeS23TosvHRZE0VD5jE1ONexkGOrXYfqlpPpZtUbBIYmZeu8PWOiw.chC8uExVepyaSnLg4rPlb2cfPoVvD9F7x502bTBrQ9P9HI0LoQtHCMK6NVzMyIQU7WIFVwINB49FhDIfyVajafzFYhen_PJEEXUkVkmoD1Ayh3eKa4bmRBzVPqdLBLmQEyc88EDk_D1.9.9KgrfIxERfugwmqucy4NZi8SMLHcQxEhsD0KZLabYAkkZNKkukV13HBpW99OGcDjb8l_gI4oCR9PKtVUnc6Llk.V2tGF2HWd10aiJXlz2LPAV8CdNq84a2O0XP9lggRFycsrSPyaq87KWos54r7OcGqvCn6lt1M6m0s0qlJ.fFL_pIo4O6DLNc30KOqh5LiuWVfjO3DFeF43kcJX7qVn0EBOT9iv2Es5iuZ9gK7gBQu2n6sc6Yan6k1EIm7Izv76Jh6QCW9x1frM2Vfk03JGpHSLpUil4oQUYgumpSxleGFniKprbtRtK1dB5kvE5urWJ2wOHpasW7nXgX5FV7lPaMNweJc9YNLyUDTgJtuLM.3DmUMYErBcSzhnG2weU3StqPi1Mg2PQEL82p0fuSdXN14L6mvycVzcq6GtIz7JkLUzXlS4Xdm9mlJ6IDd1p_glszBid7RKPRhmqBnjpx0jGRKRn9o0Z.LELmY76ggNcOe6A_wq_xNe4GrrMjKCvn45EwTJKydYqc_Hp.ztxqFKJye6CLdIs53kMVsF2SYCc9e7Q7PmfgsQdwPsiV8m4Rjda3GfSXu4aPyMhoHuTRx2nTfZWI6eLju1X50khTjdtA.5Sl4lKjtPX_YswgsL6Le9sHCMjdtR3Y08YwjiXe2Qb6_ebgxZCsg1g8Xv.z1wtpc8Xw7t16a3kqzIC6aTsJ1E7SfTonz76cRWtjLTfcUi.mb0SlT.uwP6eHMOdiVmCN3o3AdBvSCQVgBleBJchYfhqJstsF.Mz8.G5zZN0sVVDPjeCJBUuKvVsJGrJ9lqE5JMgpL.DNB0xBKGjfNzqVh1eFL551oy71.8vkirNO_eLdNYXHtk2.OeGE2dqoZGGXkLTnm9PcAfDGLA4XKgIIMEI..yl_Cv1kE3Gw279p1jHQ9NvVfpI1c6BnvvWF4lZk7xIRkJSIcPHhTO5QdqoVfGg6hZjXlH7NpsN9WlEI4.vdpy05KJDZitOO66cIxITcuMHaoKQjjrfN_jVkgrHs"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=92d5417aefc4448f';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, "\/?q=in%3A479216&__cf_chl_rt_tk=2oa1e6Cf4SWfUJ6q6MO1D2pwkQX31Cn1T.OCF2ho6_A-1744151914-1.0.1.1-MozhoUtrRXzclEo7Kc5rYUmcLunRuvwD1XGyVaernvE" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>