This is pdfTeX, Version 3.14159265-2.6-1.40.18 (TeX Live 2017) (preloaded format=mex 2018.10.6)  25 JUL 2019 12:54
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(/usr/local/texlive/2017/texmf-dist/tex/mex/base/mex.tex
This is MeX  Version 1.05  18 XII 1993  (B. Jackowski & M. Ry\'cko)
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polish auxiliary macros,
Runaway definition?
#1#2#3#4#5->\expandafter \def \csname f@nt#1\endcsname {#3}\donothyph@nate \ETC
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                   \newlanguage 
l.350     \e\toks\e1\e{\e\newlanguage
                                     \csname#1language\endcsname}%
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                   \newlanguage 
l.350     \e\toks\e1\e{\e\newlanguage
                                     \csname#1language\endcsname}%
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