<!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;padding-left:1.5rem;max-width:60rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{line-height:2.25rem;font-size:1.5rem;font-weight:500}@media (width <= 720px){.h2{line-height:1.5rem;font-size:1.25rem}}#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="360"></head><body><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: 'sourceforge.net',cType: 'managed',cRay: '9651f0ad77c236bc',cH: 's.I7qhMjlslBQ9VA4x43RUmMASh_x7vVj9JlrwhEQsM-1753512388-1.2.1.1-xxXm7GZJYj_YwSgX8qP2XlNzM0ZRT0OT5RfnVDPzo_pn8VT2zv0UJ35cTN9ivaCk',cUPMDTk:"\/p\/xsb\/src\/7343\/tree\/\/trunk\/XSB\/docs\/userman\/threads.tex?__cf_chl_tk=gsMg9R0eeBvJBe7OdaN_GY_c_Xoxr1gprrrECA3215Q-1753512388-1.0.1.1-tvIB6UBz3xyQlB2yJrFyiagw44y8raFDhnxmem3599o",cFPWv: 'b',cITimeS: '1753512388',cTplC:0,cTplV:5,cTplB: 'cf',fa:"\/p\/xsb\/src\/7343\/tree\/\/trunk\/XSB\/docs\/userman\/threads.tex?__cf_chl_f_tk=gsMg9R0eeBvJBe7OdaN_GY_c_Xoxr1gprrrECA3215Q-1753512388-1.0.1.1-tvIB6UBz3xyQlB2yJrFyiagw44y8raFDhnxmem3599o",md: 'yRo0Udsm2ALt2WRGxALKwWm45DwoFstomlDVrfw.Ymk-1753512388-1.2.1.1-0R2eMdvbl0Ou42wT4lkuxx_BUr6bs_9Sjh0V_kZJuG29LUHbdKr862pyxUTHoB0uNNO151dwdrd2XYjOJHov.StE8ylSf4uJZY1J3.s.Yj.a9syyOViZhu65JXkO2QLqvtX57AyjqRV6iFTWHj1lHBaFuKC06s03znp55aKLGEihqWMuUN3TBjuDa_65blBohE8_enEHwqrXiOxy9Y6iANZVkoqfNq3NkUcb_P6ppaZLK2aIlaeCQDts0DHF0jBQ_92CS.eA.p3zcEmMb6au8dCKeWk_OpT1AWj1YL9BfRg.GTMYUmlg9zxzwCKCQIUBYiPT.tHq2F9n.RFuvl3WCWQRHcxkOsxxpyihUurccNOf.s5wVn6SIOnK4cj_32SqUnzZ8MGqscNxyvOhhGRslLkH2JoGOsea70uPBTMxTapq29w4eu3llcfcM1yhauu2xdFw_ZS9g7kxdOBy8qGmV6izj4ZOVMuUCYL31luANQS0UA6AuAuVFD3g08W215FZTa2G53XgvqY.djfZYzyWU1nW7qJ_0ckGc0JLHScgtZrRmJKLymrH02WW5Q5_KrOl9Djg.rg3uTMkKsO2FoTBIA1xJwSvbpkAxEgR7A20y5y1_MoiOJHsdw1qNG.WcDn1XjjItkA4.ECbP0RDCrBuA._tHiY0FAYjsyMLqoqatjt4seCwsNchnX2AEtmqPz.ZwoYdZK6wDZkkdK_8PLM1swZvTzKN0Yif1k8BpBhKrMn8H2I2rMPgSNHmMDq7BhQWb4EIJ3EI9e6Dn63kxew0aLt5meFKzTmEbw.iyOpdY6EN4gva22hjpaf2mDETdrwW4Va5_UCZNWQPFXSCMlp_EB.hU7cfxd1IdhJZqR7yjllKd_xTeVj62Vw1IXjpVjAf37LxkTWW.JJt4hLnrIbNV38MU7ryzfG35BNYQG8L__N9GqTgmAXeU1V0NNqQE9PEqTNI00BywP395lIccOSmlR6r2Ev083u91o0jY7lNzug',mdrd: 'DsT9aMgNe5Hlerk2XqGdDev8wSnRltDnVVZQOgqTP_g-1753512388-1.2.1.1-UTqceNTa0q3w3oHtNnsXPf4KphvMffp_Rw6kU36P5iVtA95pfklVtIwyl5ccARq0IU0fUY3zuErqKliDSINxTJsX7tAOwldqh93Kz30mJKXH2.7Wwbbft465xHcaV0afqd1RxIukTezZf4P.HfA9C.pCq2NjBaAYC3mRo0cfnybZluGunYZVnpDkGwDVai_fn95Yq_PvCXmebuBv7KWwMdnflo6FAu0VdfIwWb0VmGwEa0v64j2uSlNV1_3TTOPAp3f7bIlfjsu6LjwpvG12LgA0xPYqwciYsqVxdm7NwfwX1yCKYNNDPPW6mS2VVY476wSW8tfCBesndA4Jtf61XnZR_.xxWetZG.PmCfDyR6Nk8UufvwU_DPGBsIrTlO.M4a29655GZMD8qTBni2PL0wugy3dVcBO_WktFMkDWQhom0jCzMFYsoDvWbhLGCgZaZUg_LNk4xG3pIvD569yzOVBkLT8pE1V2_80CkBTv1lHK7RDOAOGh9ivgMUdQn_M2CTAyVH7RgiARkYITZZYj6Sxystsal9bfBYgFnzNYKRnMFpYOPdma2.qKWQBtRy_8VvGNgfr_CDf_W45WKKXhx4JHyJMA4dSORuEcmeTgq2QPd8femtDS.abI1rJjdvm8DeJ8_y_b3IPhJQMYweGFaG1Mg3KeE0C.fHnT.mrPvdGqSRyhhj81teZ2Yw25PN2XE2qFo96oHu0swfgvj.ejxkM7473eJF1r9oIyB5hYqph0nZEHi.hSf29nwib5sP_kM3yTf_B34abrl4lKBVpwbsxWTOSwSwmFaT83d5u_KmuPmaFK7WayDp_tCWxWviwRyijzF_MTmC4ZBWHQzdsGIzHcSBIoNkvLPYr2PnMoMUAZYnbRwb8tooxTuswP4nsb1_47qKGRyougV8g_0S_ArrzA9E2tBdKxEcSInAN0tw3DQB.kIIpkWuO8buNSsjCtyIUHPkLBmcJ1oWkTjz0beqWaY5o4jPr7MVyehCDBwZf2.T.y_8ABK2ao0_UjUt40cUb8PV20Eq.DRo4RQpbeOpoOnuehP_eJB3GKsMuEaTpAo9jNDrDB7OfEDKWfOu6EqZA3kx.E0OGQTPzZ34ZUoD2m_shAUSKqu3G.D1nBT879.iQAOVwi1MigZMcMe9NigaVA1Vd4m5n_Om6BD7urkBbnnZFDpiCxIgHhWOKZYjRaT8JUrrEI3R5qczaGwtRZVg5_1rBGrhxehkyJKza0z7skzkSPnhy0PSz.qlf17C2SeFsAAiYi8JkaSxDLtDDiFw2ALsfC3CJlFMTbwbZMMb_zCZR7QPGGWz39KpXX5a65CfEVJ_CHurC.sRoWxg6oNlNeJZpbIgxAgBHo_TyS6qvZHtGdEUE0L4gA1cYe_R_OG_sqvbyZEWM.AGQ.Ngnq_7W7YqNnlvU5KiksF9i3o_epVyc.YTIaYdtv_xVep3kk_glJI72qqkoCkljaMtix3QGhxMJ4rDjEQ92TpvtCMkrwcDsDo2E6k_.PdDRBZ6SJzcfisudUYB0r1QTJWXTXT0dAhl_oMBd5Qhd2W3G5jbz0zVO2MR21rPXBkNPje71wmXMT6a0raC.D1gNa6QdDVEhA2RBigajzGDnmYMaFHhk81RImoydTccYZj6LxLmaLnBTkTjPCHOt_w4gydjq5.xtZkYgfzAzfo5NgRAoYb1ZJ6mzsCqZ0U3ycwWFbfRM50ZtldNBJr9e06SflWfoLWyghcK.9MEGoiaypwu9LEcjRuba2hk9eDGLfG3tUyVUCULlEYEuf65x_VBUBvECicL3ZzF3IVpYEGeWdX6xlDqiI.ZBvKcXNiuom_moMJDV7YPI2cak2zzOz5Ql8wMKw2ATXupwQH67WkKdTnMq1ma3hdIcyFS87rIM5daGwX94ZZqohG4sCk48ZaEJFvrO6f0DmRBq5mZeSZSmKvoYII8f58h5Cd03z3NkmGsB0odgq6iMTVPBtLBTbLbOAgnOIPMBCo8eSFjst.hEes2ce3lelPaFjcJMHHZd9YRS7Dx5lbbHJqVw45k5pir0UJGOVWQ0SsfPkVkrxqWPo1Q7RHNSe.jx.5qPRF_kFIxiTOiOXX2mm5SesLhvo82td4wh5J85Opov0HQ39mEa6Y6Kwp93H_uU9XW.lAooaaOolS0QT_0EEoTJ.T8hYu7GAQ615JCinb7Lq6hrNPQSRs_G4odO7GFQyzNtuat90SEdoFtu30DDW3gA904AzaTTT6L3ONrOJswiSuiLsZgOsZxQFSwnvVKXvOFlBp.Oak2i4hEKpipkNhinJ2ptukSlsoGH63Mwf5PJPtduBnhUFVmu4b92RF4AxmrxUMm3rIBjWRFZwWKpdLEKKDN_I.53cHtQegPVlc3jVa75MNgMH_1yM.5wJ44We7CMfDg7.YJ3IF24.FkuR7aA1oMUUM9T4EIINzF51uczWMSwvAiyAuvPbLmfe58Mq.wkLknhy2GmB_9XSxLoI4CK3pgpXJFZHx9ER0JNnk3ojBGbfGh4G1zFNqGUCjGI21yUA3bJr1f.FNmIsISFZcBRW3_9_o.9YqQJOAHyQ7BZ3nHWUG.0xcKOF9OfZbYsQuy38qn19DsIvGaryLUy6PQoUPZWycq3I8zUK',};var a = document.createElement('script');a.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9651f0ad77c236bc';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,"\/p\/xsb\/src\/7343\/tree\/\/trunk\/XSB\/docs\/userman\/threads.tex?__cf_chl_rt_tk=gsMg9R0eeBvJBe7OdaN_GY_c_Xoxr1gprrrECA3215Q-1753512388-1.0.1.1-tvIB6UBz3xyQlB2yJrFyiagw44y8raFDhnxmem3599o"+ window._cf_chl_opt.cOgUHash);a.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(a);}());</script></body></html>