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: '92db5b15eedbfdfe',cH: '9jlPT00peeABcamyYDqs4KIhiFBqfo6ZmFyRTdRA2cw-1744215878-1.2.1.1-y7nGDQIQgEAKKAYOujXh2A0EGkiwwnGZYLeHm51j0t6gyL2R1CvTdSJILO8xJXOw',cUPMDTk: "\/0932.90001?__cf_chl_tk=iLv1SjilfLXV0QRxB5x7MgyBuQiX8Jq6mQRXkkMrqPc-1744215878-1.0.1.1-vH6ArKzm9LdNPei_B.C1rgfNZBhOO4XAbMzsfkOqagU",cFPWv: 'g',cITimeS: '1744215878',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/0932.90001?__cf_chl_f_tk=iLv1SjilfLXV0QRxB5x7MgyBuQiX8Jq6mQRXkkMrqPc-1744215878-1.0.1.1-vH6ArKzm9LdNPei_B.C1rgfNZBhOO4XAbMzsfkOqagU",md: "DcOWcogPK66oQL0neb4ZD4vT7MZyy9VXO4V.SdLAsDk-1744215878-1.2.1.1-eXFMOhSq0cOVTv6D0hXir1.LGYVurlQB11trPlu_mSoUXNG.it3QoKLo4ogzF4VOy.0x2DnWrud1sFvpW9RIMJNlFMICSM9YWHMOI_wG9W4BtN22JDSv3AI77mvQTsBkVOGszmSu34IQSLen1At_Pw1nwVw9hCcdugeitcRq6n3uACHnMUbqAigPIDWm2.0LBnuFjo8S_eew_eaKYYTgotqLUqOBureDKLeoiiwivs7R6oDqqp3zwPSuk4g5s6UlWf2TjRhNrS6zAuiQR.PaumcW99o_ET.ySvXaOr.IZGrsqOkkkWNPLqyrJFMTy0EQj8aWsQKEkmxb1WQqvjjCFgXY9kZzmGEjIRz8TP4bmyUCWalnbFimK2nnNYepFCexdDL1kRhIyAixyez89mBlcu8kCzkpsolQgArKEIzWkDAv29HTGow4bIr5F_9B17UtFXrrMorroEzBXfiNCbbHQADh9VnYbQN4WKaM1UhoQAHZatFyiM_dVJpWYK3qnKUhcfoxNqKKa7DkYKOU4uHc3m8r.r89ElQc.jiZwN_dTBGp2CeiXn3XY83VBZ90clRU5iRLX49JywhqTfBo67prsOsydP_X.jl9sQGL1Ajdlw4tVuBab2nV4FAHdlEsWV5H5UoChsqI5t6EnOs2WBEBBjZZaM7BjJZO6BLk3hQvlSdGeZ83tkzcxwyIkIaC0xGPmO2cEhSTYuofdVW2br5MYlaVShdtRCQZ6AetxzUZzvteGe0c5KszSKDz9WNHPFlnJypv.zcgWqjNL7Yx1kGuyNPTpnMCeWpPmREqiQhcpVVyWkZ2iZvsaPy01n4O2jLriK_tt05FKK8YhyB65lYJ3npTJEy_4L5B9qR8P1GtHKSGE8jTOEdT6qwLJl.Joe7cKErlEu0CBFRqlRAe1kU2r0AiCL8FF_WgcJmn.DXvQ1UBdm7qq3xOImhOOOQUlFvYvDDNlhV1fHV1zN2DRBqbv7_DvvuLBscBYg8bXhloq8Yjw1wfj698biWTLNK6OHKEn9EeEh.tTVZMILNQrg4yL2B6aqv4kPO9PibJBRC8rbnyL20pA_4UJ5CvIOhWU.I2cg0F6_YSzWrU7WM8H9ZJCYDzqGTakmopOE2T8ZfamhTXCQirXRdlo4.db4bN1mu9AawhfpOSFS5zDcRhZE9jI8RuLkkIdrQhAbAhqSR1CIo_GVyczicSIhCKwI0fiEaU",mdrd: "r3gIG9WbicW6o2skxch7O57jtpjGAN5AEP1CzX25GwY-1744215878-1.2.1.1-X.uhgW9X8_V5F9.sYHg901U.K76s_82JQFsp4hyu7uudgX.20LOOrd3io.4QddJmJOZLUIWJjnOhVCByKlgOx93BSao734at6GGj0LD6QVQs6n3MBuxzGNAeaxLeQXXeUx0eeCsHorfLbWjC8Q9N8rwh0X7YMCk9St8Jn3QluBvqgd62.LsoL3oaL8cYhU2FNOyajRY7M8IWYE.JArGjV8.aIAW8RStHivuT7LqPMqt.lcrNSBWTprloeIYk63sJNSHN4r4harbRenqWAOF4OBRNORBsttlotNYILcLtoPxwDkHofu.7crUE7Fpa3ktSl8DDTmsvofBWl48Ll6HDjstR3K5Xe2_qUhYw6FYYpKQmFcQ4Q6EPhkB.5Jsna4Ouf7Mr0uZjmKkBDRC09hgG8adSJ.ZWS1Nz6cVQM5Ja_5N11SOilkmJux.eNvzcBX0s2wJ8xrGZUJBlMTyOefY_nWgzcy921AhaiSAewg0kQLR3fXYzmQAx1GkjaaJPSY0TfOAuHKkhLgTW_ffQjN.Au2dZ_e.635cqXMHJWpDWwBKeQGZBuII4XG5MyIVP.twZs2eg6AysFrTCLcLVvJOP6cow_x7.WOlXa5R36pQfZvpcr5rR.AKCC36t7fAoSmNPgPqNYasck_LBfqOdSztq6DW7gFq_TMX8ZbWwiyN6_hrTaW3nQq9taCbLdhfQvXw6XO6znM1cgvBj5Hkom7pmf572XVXLQ5JxFyIOGmz5pSAd9wGYPmeHyVCkR80EAczKylXnAcVft5Zji55qa0HU.4ieaVVFWyyxc.B1mkIOID8QxpWi6tEepvGmP6Zw75kLa1omEkq3zCVdDggP.mSylU49x3syqMCFOTrhRXXr2hlcZyNXIkNAzGjhZyvsUMzKYvnwphPuisgSYg6yWgOEv_TCqbtJp6MDV64iCXxySG8CxJAkb1KnU.uAJeKWs8SQoJibFQqv9ZwJk1s6xhJpGqWOnDt20yOqEck11kXNSzgQng9q3wIV7h_.cncLj8.BIyXRSe0vBoHsQ3o0qmDEf6wc7UAAb0HYieqAR3cJ06ntScYLx54b5lxJ0HxQvBkM3LGk4qvQxh2V1ZAiuYht7h.UCLvkdzqKDEktHbEvJuhpSv7dgY5fUfRQ3Tv9oKHkbgBXxVzdjcVRjEa8g3QF9Qy6h6.K3MaZX5iwl4t78a2riO12T5zAiCzamy_Yh9RBFG_gHQKFfze7LXNbumHOvvJKwvijcSjCDx_kc8sljkxjOZGRP0fwCIihWrU27ToXGNieJQYBOsT0_iS498uYPCaMRshjwI.XMseumrtVnx7VZmkYnPpiaMSGDZV.4Du18ZlUXILN2ys6VGm3jxPwUjGU9znqv_pCbX4ffYOXD8BZbhfbAdh7CIl18f8Cat6ZyeTeyXXLIdLIsve0vh7Hn7ZCXNXsMnJydxur_MnnOw_TwdjQecD80S2d0pXsw1bW9YWjIoK8G.oCughb5iD.33010IdWQiSrLF2zw6o8qC1RwX8kjM6HKoLFT72UePBtR5BXx21hbVPgqDEMbk6ovNXjAs5PtlpP2ZTP5EJ3APcHhZ8gINpaWvMagtH6L0umjRm9fev12K1tOnGuUH18qypK5_IwFOwTNNGU12IkCkzHH9bEqDgnyZiAbd4SIWYAuWuXnvuiuNLaKy_G11lT7_iwjE2eje71LYv4LspoykFkO0c7rta8vH4_b_xOVXjyMwCZHFpmoyiHiHYJ_ONQcgvhs6ty5bmeU86cRAzcOE8LJjHwPUdZhgh_pDIS05bN_7SVrZWEJWEr1lD1envT2w_EyjHlC.YYEtmohsZuyiknom35bcZyAr_LOrgyAk8sA2VOjURcM9Tpuw4VQDSFdFw0twCunAATWAeeEU68jxFVGiaprfwEFpgko8hoSUoXb4ImCVKCgSs7.pypRv811H4O7cY5gqo7vkTDQ4uKMfB2EVVK3YgenTqhESmWDLVRILA.2zlHz6toR_3bB8j10sLniyHXoyatANfj37Ae8TE"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=92db5b15eedbfdfe';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, "\/0932.90001?__cf_chl_rt_tk=iLv1SjilfLXV0QRxB5x7MgyBuQiX8Jq6mQRXkkMrqPc-1744215878-1.0.1.1-vH6ArKzm9LdNPei_B.C1rgfNZBhOO4XAbMzsfkOqagU" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>