This is TeX, Version 3.14159 (Web2C 7.3.7) (format=latex 2002.7.28)  26 JAN 2005 17:38
**\nonstopmode\input example.tex
(./example.tex (/usr/local/lib/texmf/tex/latex/base/article.cls
Document Class: article 2001/04/21 v1.4e Standard LaTeX document class
(/usr/local/lib/texmf/tex/latex/base/size10.clo
File: size10.clo 2001/04/21 v1.4e Standard LaTeX file (size option)
)
\c@part=\count79
\c@section=\count80
\c@subsection=\count81
\c@subsubsection=\count82
\c@paragraph=\count83
\c@subparagraph=\count84
\c@figure=\count85
\c@table=\count86
\abovecaptionskip=\skip41
\belowcaptionskip=\skip42
\bibindent=\dimen102
) (./proof.sty
\inferLineSkip=\dimen103
\inferLabelSkip=\dimen104
\@LeftOffset=\dimen105
\@RightOffset=\dimen106
\@SavedLeftOffset=\dimen107
\UpperWidth=\dimen108
\LowerWidth=\dimen109
\LowerHeight=\dimen110
\UpperLeftOffset=\dimen111
\UpperRightOffset=\dimen112
\UpperCenter=\dimen113
\LowerCenter=\dimen114
\UpperAdjust=\dimen115
\RuleAdjust=\dimen116
\LowerAdjust=\dimen117
\RuleWidth=\dimen118
\HLabelAdjust=\dimen119
\VLabelAdjust=\dimen120
\WidthAdjust=\dimen121
\@UpperPart=\box26
\@LowerPart=\box27
\@LabelPart=\box28
\ResultBox=\box29
) (./example.aux)
\openout1 = `example.aux'.

LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 12.
LaTeX Font Info:    ... okay on input line 12.
LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 12.
LaTeX Font Info:    ... okay on input line 12.
LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 12.
LaTeX Font Info:    ... okay on input line 12.
LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 12.
LaTeX Font Info:    ... okay on input line 12.
LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 12.
LaTeX Font Info:    ... okay on input line 12.
LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 12.
LaTeX Font Info:    ... okay on input line 12.
LaTeX Font Info:    External font `cmex10' loaded for size
(Font)              <7> on input line 13.
LaTeX Font Info:    External font `cmex10' loaded for size
(Font)              <5> on input line 13.
! Extra }, or forgotten $.
l.19 ...land-E_R]{\B}{\infer[v]{\A\land\B}{}}}}}}}
                                                  
I've deleted a group-closing symbol because it seems to be
spurious, as in `$x}$'. But perhaps the } is legitimate and
you forgot something else, as in `\hbox{$x}'. In such cases
the way to recover is to insert both the forgotten and the
deleted material, e.g., by typing `I$}'.

[1

] (./example.aux) ) 
Here is how much of TeX's memory you used:
 268 strings out of 10847
 2821 string characters out of 68569
 46928 words of memory out of 263001
 3277 multiletter control sequences out of 10000+0
 4567 words of font info for 17 fonts, out of 400000 for 1000
 14 hyphenation exceptions out of 1000
 23i,25n,21p,155b,244s stack positions out of 300i,100n,500p,50000b,4000s

Output written on example.dvi (1 page, 1312 bytes).