\mathoptions@on is bug-ridden. It \def's <, but doesn't restore it upon exit (with \mathoptions@off). One solution is to simply add a \bgroup...\egroup pair to the two. That works for now, nikolai P.S. It seems that the \longrightarrow problem still remains. Was there no fix applied for this yet? We had several possible solutions if I remember correctly, e.g., \let\unprotectedlongrightarrow\longrightarrow \unexpanded\def\longrightarrow{\unprotectedlongrightarrow} This is all with the %D last updated: 2004.11.18 release; the one included in tetex-2.99.9.20050111 D.S. -- ::: name: Nikolai Weibull :: aliases: pcp / lone-star / aka ::: ::: born: Chicago, IL USA :: loc atm: Gothenburg, Sweden ::: ::: page: www.pcppopper.org :: fun atm: gf,lps,ruby,lisp,war3 ::: main(){printf(&linux["\021%six\012\0"],(linux)["have"]+"fun"-97);}