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: '92e05d014d5f2c14',cH: 'GpShwMnuMZAfBd4WmoNh0pGpi1MSzXECLHXPULN7.wc-1744268385-1.2.1.1-rn2I4tnz5ks5Ml8u6v5GHO1x3YHz3Kzqd9tea_LJxvLibhDu1Gx1AfO5eNMGBomz',cUPMDTk: "\/?q=rf%3A6374101&__cf_chl_tk=EG7Ja4H5OfLeE8GInLcg19Ao0Rk59pFwYFxc0hVCOT8-1744268385-1.0.1.1-4EMJ1opZT9NTs.BV2IMn7SKXYktiz.Bh87g8HimtcKM",cFPWv: 'b',cITimeS: '1744268385',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/?q=rf%3A6374101&__cf_chl_f_tk=EG7Ja4H5OfLeE8GInLcg19Ao0Rk59pFwYFxc0hVCOT8-1744268385-1.0.1.1-4EMJ1opZT9NTs.BV2IMn7SKXYktiz.Bh87g8HimtcKM",md: "aU4DImBjGxETec9oBXMwc53GO1qbqko8KH67egE2D.I-1744268385-1.2.1.1-JJYRPKtJQd6uhGzXgg1zTWDL.6a3yeh3f8O9prXzhMskmT5tN45E5kOaNJkIOdfuBOTKKkxvfeRVbldU8ENXKoOuvavks9TYtylWn0TZvdxe9aYcYBbsMfNhyr8fP3xNphESZVzSZ6PiH54OOf5Tl4va52.8eaf4z2I6OukvWhsJQmO1I_ruu2NZ2gcVWS9xz78hj8EduRaRh4GOZjXPJ2fixpdqbcqlsaIVtnBj.9MGb_hQdHDrSFGkNPY9bCGxVMUc4FoOeNZm0c47Ve0RNh8ql_XjQ6l_W_X6LTWcISXZLWLVBP8Md2TWzK3Xctbci8CvDisJwm4BcYXDApQ1uMJcbQ6rTgM.lH.6CG2b1yqSJEplcpqcoNvkYDl1GmY.1MvRuRN4mbHNduNm7Z_3Ht0beYeNbzVkAcNVHJ9EzfTgYNJjd_kEgG8x12bFCYLwApPwWCYDDphGHRdlzkSQDKqxZJMrfGpiSQJog4KwAg.sBEeNfECRa7q.3h6iJtFD0_c6WSbVc1PThxDZym3tp192XxnM2LZtF0MrFsGqSXRqsBynGRAZgXap9goduEgrvQlqrwwIfYeNacA7OUJjE8qpzrhNWVsqrJ9TJ_75.GByASiT6fp_efqpvxwHHPMc1GJUqZcPfUDVs2NfLZUYUBWnlNf7HFDIQzkoszgVejUYeWgrvs0emzZLYewquaNu_sJSfB.PVl5JkBVzk5HuNbd7jmMrhF0Ul6NsUEWaj.a83FGe9V9sBBlmWACEUNk4_rMiJhTQQ_4xoAO50lCJH1cMYifnTJ3JfoHniknHNBShk_T9eg78AKrAjMGgx4WV4Olhkj8YreUWZCuuznB6BRFNyIZf_U6Ju71Oe1PunjHIcaqDSpW9TA5c1CvLwedz9NumKJEno2aaifF2INhX2u9EBSjcET.0MJlXWwxKR556QN8RFl5EUqKNHIxTIsmk9rJ2XGJbaJjCgfv4CaBagIyfga34bTysOKqvAsdkH1QnbDU.UarR__b8tJZ3SWMktACdoLju_AibfsvBR414gMEluaMx9eXrzCXLrzDJ9psIMnss7jfu_YGd1zQNp_sFaWqLxkFoGxnQKGf_bSAvFkYweinJpduscZc4ZScgGBly0_r4tggpJ5F8PDkMoqOvxgW8OO4XSlbOGbhIpYi33ET26ryHWlJdNWYauQmCYYVcudEZ451tYfd_vi0.wvu0",mdrd: "S2231oDlz9L0dt2nZ_rjQN6Zn6bBiwMTGXVmJ_WTf80-1744268385-1.2.1.1-_8KdyTnB.yjr.k5Y273jo.N1VSJL1OzWX45BCcNSK7JyvjN96h1z6whzOkwUptCeAmUsWFp5AJKickM72Uf1NvVVdqgjsffEbKjsAU_lMjKJ7DK4bEQMxSvJq7GeAGwRJgcokL2EL7bfNSFtGC.wDJ.lnCNfcWVd5IkVv8kjJO3.muoG0XVTdCtXMLSJs0RHVkiBvfIyXI6PjrqTCmfYwd6KfmqvtuCfVj9FMG66s7iM5Hv7.Mfad5GJOkKKBjIByNPzyTth34L74d.vDVBpGaKLLqlsVbJSWlSvLsqqzbJEKPG_ukRZv8QydHL7N4fsTE3HJuFxs8r71177j0y3.oJhOjp34GcUKEOyJ6DhVHovpx24plSa2fJraIBVc_zXmAZn.UOZBvEiky9sR.X9fhZnwpva7HpYJMe2X_JEsHt4AcCGxcnWjIrshKiuzsh_Ksw1HYiXmGeGkjNEX2dTfic58xNLqUBzu5JSyngOwN1qeL_cKTaBxnaRGP_kDEo0ecCsmQabVAYb58mRpviCYIt0SxpSXmPI34MF1ZhnHZFsokDi9bzo4QA.B8mNCobIzbQ6BJDaBrPF5zZDWqj0N.E9_lm1x56nu9rlQaIjNNNJayx3MfJzRlontQMOguxf1RpmqE2_VbkN.mHlWOOfeXJmvamHvUr12h8tIyu9LEa93FFAA3N5E2iz74C2SAFCCIvvBAUsWkqtqiBfzUam.1S24vJrN79s13MuIOl9vyPJwrdb2gzN7TWaO7ZFjxGRwo7WgBcLtWbuaZ2qgsX0.A4dMnwMo9K8VIEEiQWaAa5MtUZ4Eq8o.EoiZByoSTz9wRhotm1NUgB5McoqhgmAsQVso3GPp48nZcmpkqW3mM1xE_ezjeZsUn.04D3N23KkwpNBSOOo5mKJdO27vlMiY5WCY5rmgoPuknz8HcYl0pS68aH8qGO2cYV1KyGvfhtqvBl_YCBnUsAh.S3GPdM_6VXazZ8eIwj3LqPGKPSqCFZ6_UD3Wq1nvzccpRINNAxSwrgyC3Wv.oQmImTu5Gs5.OKEfxZya5W820tMb1Xy1.geYJjJUgNlk4HHbu44TW7DvDh_5JoL_AqfH1M5tMuqK0hOXrHiAjrzOh5KBNaqE85myMzaUTBM1bqZEwih3YvfC_klEQhQnMmt55VXQayKUU92Z1QWjcks8sCPiEQPqy5HasAannSImnor2P1DudGQiT2ObSKLAu1CZHAkFIIq0ms3E2.jfWuJT3rT4AYD9kR414ki7gLLWr8cmeO1rEk5oiB2atOOM8CrDqXbznNE7RA8d7zqkTmlNW8vqGtBfl0aOrJBO7Fu9oMShNw0yI8hhepKitWn_5WvIt_K5ZxNZCbV26v62fnWr7hiS4.lDGci177lkLYMoj8xvUQy29vjI8YtNUk2Sa60TPd51h9KAaW5jzwgL0V0oKGhgncbqL18yel26pzg0dB14BKIjc.LXaOWyD3Vnw1RSoKn.sfy38F5BJFKOTs8KV1O_rL_Y0QBo9HRhjrCKCT0j4pnCfh5YGrUEgg0CuRDYV836zGyCTdErj4L_IEUGH8S4jDeTwZM.m4_bXAVrJepZrsRvUVRMirw7CHRwYKT1SA9epnBChTNU8d1es0cwMrA2QTCh_eBOJWcl8d1TdgByU212JcLha7po7X1VkHlRYnsRPb4jI_vVpB185Xb3TIjyCM0laqUrBKQJuV9Ot5xXxZ4IILMCsazIAUPAvbF3Xo9aFaPwwrS.yDY7LL018lCtU14yHQSNsSWhmYUwdkR6Bv_V8bLn8xp6stc5g1xbYsTNJFTiMWSb0HsAuN1l9rAtvUixxQY2i7u.3zXSLQVPm_9P81ibHJ8fuiWb_UJ4XNJIWhpveGzz3aUEc3EQD79ZCmizYb3uKpj6Z6J3DR0kebo8dG1x5iuUog9sZWRksMtR3krcoVHDTnCQSs_AzDnsuzGgRQOKbketgoLNENsZ4t4NUIAUSgA7EPS1jtS5GDWR7L9XJov2xasnjfWrpALCFMRVkJX1GYTIn1OCOEJ.HAHGMtZRrWxI2V8DED8tu6FuP2ctg"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=92e05d014d5f2c14';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%3A6374101&__cf_chl_rt_tk=EG7Ja4H5OfLeE8GInLcg19Ao0Rk59pFwYFxc0hVCOT8-1744268385-1.0.1.1-4EMJ1opZT9NTs.BV2IMn7SKXYktiz.Bh87g8HimtcKM" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>