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: '92d8f164cdffce22',cH: 'tmhDWLUrqV0u_3wQ.nhL_Y6y5bnCz8vWKC35gpdoiq8-1744190577-1.2.1.1-yzhdX7ei0MQs19OblvXSWeYF_uEftAEP5Ij9QFCZE2zqAplzhAVrpcIP.fX3_o.y',cUPMDTk: "\/1299.46008?__cf_chl_tk=Evs928I3YRhOi0BMIuzY0h3p_tpfiyJxNEhJRZ9k7iY-1744190577-1.0.1.1-o4w9.QwZwa_JxwBIWWs_UBHhxhQ4TuFpW_u8J_3T01A",cFPWv: 'g',cITimeS: '1744190577',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported_browser_beacon",fa: "\/1299.46008?__cf_chl_f_tk=Evs928I3YRhOi0BMIuzY0h3p_tpfiyJxNEhJRZ9k7iY-1744190577-1.0.1.1-o4w9.QwZwa_JxwBIWWs_UBHhxhQ4TuFpW_u8J_3T01A",md: "mL6qpmTZ2qMGL3Y1TJaXAQyiWXQrKoK.gu0rg8RmYsY-1744190577-1.2.1.1-_9zSrhAPJrUYj5YyfbpKTvXDcBXbFL6u6b2RvBJOm3_TxzVLEdObskPduU1sTcrq9iMaRoDGhmGB.aYf6nqLvH_4fcqOwqdFOh5OnMglC8cf8y22pYJJmxh1wPyuBjkA.zzxhUz2XkJWQqrMmmvgpiZ_zbHYzZnpDWqns1bI07AZ6Y1cwQWw7iRJM.h9geA5oDlQ424TYFm623tCzHJCJJfa8KcX2vFp6QAir8lJwF1Hc7O5aZnJRggvNLEmFr6sTKoRQ4kHFCI3wA1kcqngEm69Q5xfUOIl5rRzG63QV4erPoK44ojW9NjFa7F._DBnsPbAks2MMzd6XPlmKncKLTjPQapqpQBOxlkJgc1LoykCoxx3jvyerfjcw712fIvt1P7EjX25R2oJG3C6Ikssj6D77g_PnaOsAdZC.mpVedDVkOYADKNxqwOcoKnmLMWsHVhEGoff2iUSN3VsBsJpTG15NC83LILlP5AMlYS7F1j0f4li1r7kZVAbgV6DBGSy46ixZ12.vDFRiFWFX6at6FhoqIuIkg8C1mQ6RnJUL0j_aomoiUCP95LyZZ1ySsfv.VamP219ThvCj_Tq5LasJx3nmy_PnyHXJcR64KTU7KKfWhquBfLRQNDVlRGoLVR.fEd4Ix..y8VQjnzDZm1FKrpToApF4KkWPRUMezhHBP4NoY9krE.5FvuzD9PvVtGM0p3OmmXaRLS1AaFQ2pSaOFTYYejoMapd.kjUTn4gWhaEWQub_Ik2GIWMMLIA6aGdE3xstd.KlDtiS0k6NMUWP9_5DBb4fyTzkMk1cD12x1p5n7GqiKNEJcBCJGOCVd2kCcSuvZELGS7KnyI5GvTjIH9_tmACRp6L9pWKvQjstfaOwVdMPfifZSq0E6DS8w2InnQRf5NycF4ggl0zmWpcEGb28w7UMJtpo6Izmb7rtvVeooh2hB.FciwLlBaDdh2sKsGXxRA5VohY_9IkJs0vJaPAA0J447TZ_OxDZpVxBlfmgm817ujo40X3G_Q.dMQTc9i0elP8CY82G_fnsqWT9OwmKyjlJUU2DVfGGwkG7QUkOtJhxHK01a3HMlTfGAO_aZHSViNJJUWBOO6TVD0z1N6YTJwv9S.MXk9eO9uEoKEOYYmRBiOhvbtWLYQu7crhF4XrAiT8I5VXO3QVARHXfUdL9Pp0jEIlISseow4PiztI.GyI3UPStZJgrE_BmA7N",mdrd: "264N9OlQlWU5ohK4wYAqslS.Z73HPbYyMppcUkF5SwE-1744190577-1.2.1.1-LZj.cZMivQmxRsH44WML8uFMRfvoqfW3hYCSxVK7iIkcZHA8RkTA3FCozM4Glh085H2c9vqd5C35mNpM7WsxqqLm4Ioh36PFzl.8OJctIcCOTOS9l4svKDtRG56Xw3nYsUdREa7Axo8P2UbWgS9hIp_TAgMSMwcSOocKk5bNhC5IhvE01PPCjgl0wy8vMnR3scnTUFQ51HgmjWnQUlOY_OPb88aB6k83vtPpsO9U3z9qQfW1PQAxWioO4AcjnQN1SHAe5lGAzi7VWenV2Yu4oGvuLeKAtBc_8bCtetyF0_TKgh2Lq9i.j6Fze_nvhJ6EJzXuYMkLFx9g9eCy0ozEECW6dbWdmAYbSUdRf7EC69dL2Cqm_mpDuL59k8.mQ_Rm_Un2u.RY4x6XGhcSAmrIAqPJ3uICJP4EpNe.h2sJ1DL7DllnZUpmEqMuJzptmx2axYOadW09iUCUp83xATy5ksYHXTbERycmWRKbpD9BhUCkpyIXZPNt9DouWKQlVcsGSiEwG_ANBtn0I5P69jTCKP9qRkOAd7_WMfqnA6U3vmRXfuW18i0ZfmTTh_4AVnm6TDEPWttwNQ8U0zCGeNpAnqbPnmOKP4JN9ZfY2YVxqb9TQ4vTRGRvUsN6mKqXNoBuX01xQWg8CbYl8ZeFIFTt5ZLfFJxtO2DrnFxM7Sfo94cGqr94sLXD8WuosMB0xRAG.0rvnk2Q.m30DYkL2xZA8mxa2oHmrf7eosjVSkd1DgT1x.3PsY0LtOhDYYYKuctW9IkGcH3j.XaVf5dUVhFa3bqaBulODv.7uVHcrVHTNaGQbbuuE69_0Q5.kYMR1zU2aT6z.JY.0T.8FzC89OB4fPkT2y8AqXP8OBqdmZEItMeW0sLR5X1V55WL7K1f7GIHgqZ0d6QlC..JZDSTIMLXRkwjmSMERtv66JQq3xo8Li6ROIvHsQqAfsUDUfYE1Qam7Yhpx55HdT9VoqDmDGp2wWyqKbi2HXqFDidl0g3XV_eIG_MlgQTp8TNYtQR8ta3FfKp7Pqe9ACCN_XoEOXQlcHZxLBh2i..wiyfq2_DoKvg3Y8LJ0lxWZj7pR5sTtLC_pe_PRS3I7R3p30C3DMjfbCQUH2fmLYCHh1eWSYKoKytQ7qMwp2SxZx8K5xCjYYfWATlYjrPrv.zFdmwMLS51Gyo_R9DWiPT6BeH_boQgdhkosnya0owrLOPXu_ZjG3IUusP7S6nWVotkELKq5aX.DcHJFzGaw4XFZHRTqeOgqFPYMllK0VvL_Iv8yjjhHYeU8SUggrlLcI8tHSu3tG5CtqUfaOtF72QZP0XudugBxV9F7AsjA7yshO2rvqG4_JSLchp7NuhsWXB8bfzC5Lbz8nvIHKyVdSMP14lGll5KKoMXOl96LBc2QVb2sSpHeMSxwWzojDfVbtIek4fcCWPuwe3TKpJ5Mcg.fg0VZz5rjkHr5Dw5.tWfKRCsAWpusOYXySdpf_nBbfJDOo0NlV6W9Rei1s3Kpben9V4lidc8fdPB8SNufFNvR_wB4MeNWglBGtijrXQ4IT5zV49a_Xb9JEjDu2pJbS9fGomG7ZFFLvzFL9Y4Sqyn0a_UVKlx.sPzAt_4phcQFHF8SlROg_5K88bbMkezmPS49jkkC6nW_fVywzI0hMdX7wM29leN5NHiuBWMvlqpRj1vGn86uR5I4sv30izXB4YSr142Yvfj5e3NTHzFiWoYFWDPJdmRKW_kAOUuMPWpNEjkaWtRdWT8QUPNLxp_tRbe08SPx3SorTaLk6pJKQn426ulxTZlGxlCBvg1H9390Gtv4hSmNZpnu_mlsL8x4y1ZTfvW5k49VND8MOCSyq4kC4F08waqowEHjEZwqfIYl.urNUXzcDCmZuPJY8WCgwSzbMrC0eQQz52Fdml_VEJKBLp2eE4ezZFGSrmTYKXWwpg69tv2PrGaeonM2tcyLthjwmRHVK8Qgzz3ZxJqTaXZQGQtmycfsl2Oz8NNNdV0PI3BA4N4EKEoGmOhNa.PmFvmyMqr8Kp6LDrAKMMYBkcYX7CfP08OAMnCc1ioEYs2Qw4vau4P253qog"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=92d8f164cdffce22';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, "\/1299.46008?__cf_chl_rt_tk=Evs928I3YRhOi0BMIuzY0h3p_tpfiyJxNEhJRZ9k7iY-1744190577-1.0.1.1-o4w9.QwZwa_JxwBIWWs_UBHhxhQ4TuFpW_u8J_3T01A" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>