This is pdfeTeX, Version 3.141592-1.30.4-2.2 (Web2C 7.5.5) entering extended mode (./Chapter-2.tex [1{/usr/local/teTeX/share/texmf.local/fonts/map/pdftex/updmap/ pdftex.map}] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40] [41] [42] [43] [44] ! Missing { inserted. _ l.2792 \qquad||{\ttninepoint\it $f =~ s/__ /::/g;} ! Missing $ inserted. $ ^^M l.2792 \qquad||{\ttninepoint\it $f =~ s/__/::/g;} ! Missing } inserted. } \endgroup \endlines ->\endgroup \medbreak \noindent l.2799 \endlines [45] [46] ) (see the transcript file for additional information) Output written on Chapter-2.pdf (46 pages, 242079 bytes). Transcript written on Chapter-2.log.