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: '92e36b692bf2465b',cH: '8sKM7RG2OLqGRaase0G50HrLV3o1UXrppaxfov18rKY-1744300432-1.2.1.1-Fq9tFWZPtM9qpxfkR2y3m3wi0y3XPFbabRlxdMAwwWqMyNBU2slTvOGFJVvsQ5vr',cUPMDTk: "\/?q=in%3A298804&__cf_chl_tk=VkptgjTKzJF.dcM8P7am8OrBBW9vzBmyPoCVDgF5.t0-1744300432-1.0.1.1-XdNWW.BCcqJOSz9c6peJ5IObG7lR43iayFhTU2COlzI",cFPWv: 'b',cITimeS: '1744300432',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/?q=in%3A298804&__cf_chl_f_tk=VkptgjTKzJF.dcM8P7am8OrBBW9vzBmyPoCVDgF5.t0-1744300432-1.0.1.1-XdNWW.BCcqJOSz9c6peJ5IObG7lR43iayFhTU2COlzI",md: "0SbNGJQx8ZC_wH27PIlt7nh.pW1bUF92vhf7uKcJ5mU-1744300432-1.2.1.1-bdTjxI7pSnFFpgupi_20NnakPCkG3c7JJEfUSqnlbT90ND5my2yD70y4vFF50CMcCS9.tdwhvJd2DIUGVvjgOLwvxSLt7647Gvg4HlNzpjCur3AZpnZlBYq41divwRDIoxEvR3dtu79zqJPD8GTtpWROmJUfGpJA4diSiDwdyENETANLBBBFmAgaEjQ9T.qeZZ5_jZLv_mwwKuuarUFnCCZPZ9CkxnqpvM..n4xXlluxk_6kwYjxAWVlMBsufBr07mG8iYVW.hgIDjZ3.BoDgZQ3SGnVPRnO2i_sxmvvvnbaXRWtG930tivj7ir_beRnMzRH0JB4eiMCdXqXNcVuYTlSRVBXqdruhjzSGX1qNQqmC5_wiksu1dtCC9MdyLuQ88EYNjarKne29WrMVSXrDGTGaL2Qd94zC3_YciX9yaRRmbfS0g8JwkJmDvg3V7WRRKKz2h0a.c2yoHRXjVryt112P7bzEvg4WidD1eaMyeVgHDEISuGmYhC.roZLkztE1RrV5q0euLkFkpjQZAtIhwu8d2ILBfZBNr1cA4BQCwQj.V6trzxRN8Hz_eTf9aRZ5i3N3Z85dWGPvGBj_HX4DG5AULWA1n7EE_361MfHwGz.NbehXQjF66h31KO.GVsAkyA1l9nLGslQ_X97yjdflO7o9n91G1YWqQFagpsHP1JHeX3jWFeD1t95SmD6TjmCXWAtQYeg4NKSrxcKrzr4MzurmZW.Zbfi8OM6Yn.yXU8S5tAXMw3bC_Y6ymEn8lBtys0ds1AMmBJw1hlA5QFXpEPblhRhSobGH84MhQIbYM3xmQBcVIW_Q7G8jPCr3H.T1CfUboPNDMqBzWWtt6olW6ol..WJKAJSn3X4uGSSHciLIQ5hhCyYsolNrvEytRHgaEKHq4ppctywWCd_ye7URlKQoOec7ZDJyndjEiYdLPzdGjp0UvWwEnN_gMvbCw2eDIrTauFLiz90udQk_3opmdaLl7E1f4U8kp.eYz3TsRTwe3TmSdEmlVHuglC2Zmtq._RDe7xOg9TSeyKuf1p3at1w2XxpPQkKP42MOaMh4MfWpyNHcy_sxQzSVo1ahuMp5_aVyj2MFbjro24ZczSNJDonXOPdtaQG0lB4CiNadQ4yKTi_0D5Hpa26Ez9BCtUs7LFlAmF5MHeklSAo6m9tR8YCCEPJeSiht.Ycm.soswXXIQ41z6AWwY1Yy1eecwqz",mdrd: "xsvMPRewkMfQTnVGpqg1AeXHm4dlDoP.DalbMwQTzhg-1744300432-1.2.1.1-HSgDO.b7f5RWBdatLbtYJgJJPjhHymu3nDwT0XZGW77r.nZrJztzgumP4_yrGVmNdrwbj7GQSydVqJ9vfPwHgRYDqidPMsLLp0ncvTpW6oqjnPV3Oe3AlLrj9rtPa_a8dKHLFww6xMTpI_YBytcBNPy5J.LCFv08cxgcTcDfcSG50ukQp7hHJG93H6T3ms1Jtm1taF7TbO_tnoA8qv4JRA39QdaGgWhQvP5dF1BvjN9gM9jFLiZjzxJ3ONzQohfqdtU3HpkuPwEPKD9GjRq1zjpVh6vRBvV14YggH3GjXV1_mX9b72rM6V77KjQOx.1toFxbiHevmOKfJizUptU3_6lCbfiuee6cslEqIh57eC0bvTtsHhrd3MNxbtWmRI9mPbCf_Z.wD1XJxw_dTRO.cCKeboRXClW6chEp6IWrNvMGeSEi0FvgRVMbxewfy2igFCzJ6F5ciUhF8fJN5M5WHNTHKx9ZFupy4AhOUMJwxKXNy.DHk5F7wqGBwZUEw2dS8_9G7O1Jx2QqvkYcdfKXo1QGhBAoDaMuhn8WpaM8UqHzAebE4RZ75Mp6g6bIyc0HCSMROJchjgQLkgoTuCSLkfgJ3NEUxCGeLRBcE6Ju0hp5tU.o6qmYFQ30litEKg.BtnaNABzqigl4PZnE8pLQzCpWmaCmVJMiYLU.YodsbMJ22xkgK.W0KJLMCAq.rObBYo2PTgddJk4_xD6wX9iSYiu9xS.IsiEzwpdrdkZ_1O_XBZ9RoQFmWwyINB1ntgxtiqWVRs3pNvKnkAhDOekncGlno_GmVvoHmcJy8PF82GAyAwx9D3oKqsUog5bOB60YFy6T4x9cMoovDAsWGgU19NFV0ciLXhmpKrPPRc.bkycTzZYQ.2rlUFaXfgsxyGeJ4h58zKht2Wrncq5zwJt6m153I4amWyJi0ARhl9AmqQiJsN6vIX1N7V5BQkcck9wz3.g_z14I5WgWuMpjjcK.9F6CA3laOfBbaHJdicZIWODciKN5JCQkqfjFUD0qz9YD4QztFsDMZ1VFnyl3SK8XSybjvEUamuxN8ffwvq13Aadr9aXBnlJ11I.z02bbPztIdLbgSGjvpULADC5KpuHZsyltlL6IeExfr.kCuwyLZ7Cqq1OW0j.rNeXS3hRj1A5.K23G0GKj_00iz2wFrWnWN16VyLvgDhLH1i2lH1xa2ft0WFqykmqkHzBX.S8vZBG8_.C2zf9olVv0aFHqqJCY8Jo.HaT4wrdsXFspq1oiGjEyIj8onYe9.GG1sPmCwBR_3ku5XDgWzdEPt06tTn6Rt0rQFM.gvhTcKnkpdEKr2CF3fOQ3Y2HKXxD.FSwz2On4vfx.nfD._jagC7en4VLLRPXqZCa0IvQydxEIePu7pheEuEV4kIJamkBd8L7h0XZr6ohQNI_SbHSuCo59DBOI4JOH.LvN.CLBtgO1PI.H5G3qiaMdhDGP7r2pjw9QEMrUNm3cfPeLLKvlmemb.2n359.idFn3YFKHXrp6VHV8d2V7rArTYNSt6gQlCUPksLUYnv4SHudzA5CCn70MbtD0kVNgJR_c.S2d1dKWXxyTygmeRYFJQPlQlVtJKzA8Yn0tA8AiIWbjeS18EswIu0u4ZD3ZEPflEx5omx13j7fJcWb9tTGE.NPVQfr9X8DEUdMHlv3gWIzdmcjg6.hALMYLm9ZZxE2u8FEadNhcFl1oWUmhxjDBerspkDMf8Pu6k6bKJgVNCdeHVOFwYy1ZPxEdRS18Bo7CeFerWvObd0z8NmaYjgoA9nyVYbuzLo6Qx1WXs6iW86eoBuHvqUUqw_RHwAISF66HO4ua.XrO.W3gC1EdicFSsiO5sFbhrk.1sTDVeC3wWSTBk6Vbs8aWeTL0syxMoQSNDjFQIbLnh60Bfd6LLtLojUJ5LHSn3DK9iKronVNSUcDaf.U0S_e7mB4Gb_eoWoG8xrhC.HDL0YvT3sjWUgLcHRQe7NjOXpYa9a4SqdCKd7RGMjfF70oaU.KzWUa0UTPGtcDUUwdyERW7vJKLWUf3LkVkfaoDE2h9J5wB"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=92e36b692bf2465b';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%3A298804&__cf_chl_rt_tk=VkptgjTKzJF.dcM8P7am8OrBBW9vzBmyPoCVDgF5.t0-1744300432-1.0.1.1-XdNWW.BCcqJOSz9c6peJ5IObG7lR43iayFhTU2COlzI" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>