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: '92dde2f4ea0fa023',cH: 'SfxGWV0daSj4QPnJj6OuoXtF3J7YurF7MsljJAUs2Us-1744242414-1.2.1.1-_pGfYUk90ZZTuG_wgTCfUtukj6ndtfiCbDS8EcYv_5FZ8PBIbLEwrpciuR.ZMBcp',cUPMDTk: "\/?q=rf%3A7341873&__cf_chl_tk=Qj0LkK75G2pPCn2BwhUf2LJ9BgQaG7zGT.FrPkMesxI-1744242414-1.0.1.1-_a7chANJ8CxiDS_RcTPvyz_fyJkCCErsgkuKS116BfQ",cFPWv: 'b',cITimeS: '1744242414',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/?q=rf%3A7341873&__cf_chl_f_tk=Qj0LkK75G2pPCn2BwhUf2LJ9BgQaG7zGT.FrPkMesxI-1744242414-1.0.1.1-_a7chANJ8CxiDS_RcTPvyz_fyJkCCErsgkuKS116BfQ",md: "S22GcN4rJEmjlkHSKEZAnHpzo.mSuuUswF03dIlamdU-1744242414-1.2.1.1-S40RcrztBpVmTqkY0bDEMOqm3cARPH7afqCodR2OB0M99GbOCL1FyvznVqRz0jOfeMEfbxaCpmbrBIqoXNYROsHlx4x9OooOBm3Wv6KqkV_DU92dd1TQy3MdNypL9BPWuetJyjKhuRYboCj2UtWkidCyOdSAKpvYtxV8B.jnkiu28mhVY7Ed1UUfdzlls30X9woi1JeS3.4lyTOW20JaechO0GLhpG3UmrreW3HdMpI6C5AIP_kuvLb.JmjTLGLupH3jooKZuR.CUnpIHGakgBA9kCHlO9RJKpcSCQbJZ5CAQlwhf0t5k0gKuxEYT09c7tit3tzoDO1TVPJ2Q96KIhIYzEQwD0VaMUuVMq2OiUXVVbY9stELTQ7njPofeK1LCqKhGjCzAztfXjCsYwZ2pi_1CpP1xfHTjOcGzh.vvza1_tfoH7dGVKebAF72ZTe5cpgx7mISTg7Id6sVD8VEDSdgSwmtLdSJ5DE2XpHCoClhx3SDDvf8XQV.QfQY8kN.Yrxbyae5QvPE2aEc2pOQ4byPKBrH8VaHRcNuBtkTzF1PUENLvW4koTTqC1CqX8_KhP6JA787Zc3zUWPBDJ2fuH8SQbdv29kpLZmwqjl2Ar3mqvrgl0cny.f6HMo7dPKgac0cqvtw5UQQJnVJytMH.RtFXO4QPVVbcGJ.8m_gi8oUMEMOkzJdIrVStSkNZVA0Q15T8QpmzJulVWyf2rwLDCFYko.UbPfjocualJDMLh67KUm_JTVNCAD1ksnLdYaCaUKzkmrPYt7R_HdFjIAxV9PvF2Z_aFAxlsVRaM.G8VLT5LVX1PsL_mLGyMR5.5aLSRds.6DlbACiDZsIG0tWYcc01Za3lrjbGkBlNf9g_6Za9NwsgVg2GQclFU4x8uHotpNZ51TLViThhppnN9WMKxJzREAowgjvSmUy2uH5DZ_U2pFHxikxLKhHXj.sPJXYsE4re2ep48f1bcgBnyUnHnVp1B7Cjs1QN52tGrj8f6NTLJR6friFEQQgYz.LQ8LuxMBoidruTGf0yAfV1Y_aaGr1BVs2EvLGt5UOTIB0ShF3fkXQvEnT4MxvoJEdlxunu0dtF_HCpqd4LaCnj0OD1izlSOIg1ELNup9Cw23KfKnIRW.q9eE5VKEunp.AUn6q1TsKly7mVlYY08yBTRQavT_mezeebMQQ5Hx.SK05HYKisCqznlnHKrMeAgU3t8i6",mdrd: "8YCwrFW0ol93NDy5X.aojjQ35q6rs.4XXjT40P5KxWA-1744242414-1.2.1.1-Nk9faOz30wjFrCd1Hv2gcP9CYo8I4lfblO.QMKv7y1IldjogV6heCvcLMyvrzqMbgGJAVmecgVHLDFohidGmoRvMqvH4McK9n4i0ZXgTYUGFH5IHvZieOZvDGABa.RO2X0Qg3cMbShAn8.Y0CiSOGlx21_YNb5C_EPk6nOO2u1HWjDc1WzTBTuC1d7didXRLaigfm7CJGSPCeF7V37q6BbVKrzYoxjnWiZEAu8PlVD555gWzdMxaOdBkWZ7E0T2EhROnR6G90S30SRcOPf4lW5wmxXQZsw93xdJL9w28pSEsk0pdCuMLHcLYkpL_AhlhQ7d8X6tary72ySa0RndRQg8ajN8k754ySfKcSG53isVf6yNWusIlzPA6j3hIbKNokB9Add9OOjl9VXdLDM9wwuTYEL3jAOMPTHnM47TS6nx3R5avaOmi.wweHdeT_8X79py5BgNOIxdKsF8MZlYlCewFEgasKljBm5g11mkcbEwbvfT7YUVMIkRt3cp_pD.F6Hi6ZW91.4dqeiwqp3YGPSzdU6PSt_KD13l8WSgSb.H7X0AJRoBlr0ThwmTe52FscbfM9aLd5cDRMo_n0gX7vu936GhnuMiHf7f1WGNdLwPpta_YM5zYqOARzZQkU8KKowYRT_jO2YHBrYzV8WeVoMBm5nKJSpVBMgdnkWz3_CkRCP5TyyucdCrLxVVIWKN_RoKOlLpf2MMvkSMnBhfR8ByBvyVsUePTmbyOGDYvCAynX99dx0CYa6GyaTE563qINZR9CFd5GxuVGJ5cghBhSz83uy.yQ0CQcWIsu0RCyLvxI41GjpTHufXdho2bYr401ORkHGEA4FRhnH_wOdfccpkBimp1EWUGOAokTbk91.TBGM7K6S6HAyFBhAL7PD0KDzT7a4M3j6ESb1FukDoQpg2IRbBtnhqLlHEbCbtUoAe3DvPBUyehbWq_jV0VFxunv2hpWSExfkJkH.3ynxMiZvUZYmxj7BhG2FvI7Z1mgDaZ3n07Lcjk7QmCubx58voRslvi7K6qTUzrKuOvaUlJxhWAd9.o39fteyeWDb9x33KwXISNQIaPy6.ygGoLtdvjzo4GPXC7J_OPTECTgkaP9rmNypnSUPr3oN2By87A09osoJiQIMrg_cSbWGRO_QRk04Rh6yR1COlLKnmdRQmJHZwodF.BhbkYkWUCq5eMvZnuimYb.bU.3tLjePs2Rm5uk_swBTsU8csXsDOLjLkaF8.bz2p0zLLIRgQsO2rSCsB7guSJzKM0r0Za3qtWBJ00DAYNOtX49IL_e0XhZDtuiDSbE06F0fsxMgnKKCSlzHNLjLPAhWVILpZnoa_FTAyTSt8TfQHOtCTuNuhTqOHKovlqX_Robrpnfi.1KtVXZlLwdLa37zj_nuV.2j5L1HOZu7kvzX4nAT7KxmCXdDI7XVQ8rJ6kd.acjA1BxQ2zTOEnIgx.tixu6OgoG5du3sc5KX6mCxb25TvcqiYoWOd82zbflr9u.OY3ZgLtwVRRlZjoiuT5UJhPtX5FosVO2QtG.sOasgg5cIzyNeKqrGkn7Kbb6yH_G0I9dZbnjcHsOd0n.fvkLuMwggNPGdow0YGiHPWVf7vADUmfDy27.g3B_PR3O9W54Y5kQ18XvnXTBrfkojI.11kCDCI604o1uOVQ9LdN4PCYa1IZNIJpFlvr..Kuu1XjIKu2NlxWAYC63d_O.big.XRKmJp9FfqN2G2VuH82yJKFcjwhUqiCTaEzxKZ5uz.MEn9Ee5eafJhAIYMvNQ8L2S0Tge0dpHRb5B3qyIXGhXpaACUV8qC.fu0l6Iyuo0IU8vbibdpZOiQbMJ9y0EHv1WAyWAoA3JomEtQOAflPA_lL2kZ7xkVsVB3WjIPte1sl9RluF_RWfiPJvvxoR_x6Z9FkjNY6myyjCwSwGeR5V8q7aEbgjn6o82XKYtO0gMhYC5fmvcRfnZKYwkc7l2VV6piSORTAda5bkMerELJQmxZJzjmD2ObKxaNs77T.MhQLU7I1XiXW1S085PTBYuT_WO6loxOuYetQ4uh8"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=92dde2f4ea0fa023';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=rf%3A7341873&__cf_chl_rt_tk=Qj0LkK75G2pPCn2BwhUf2LJ9BgQaG7zGT.FrPkMesxI-1744242414-1.0.1.1-_a7chANJ8CxiDS_RcTPvyz_fyJkCCErsgkuKS116BfQ" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>