I have made the sample.voca and sample.grammar files:

.voca:

% NS_B
<s>    sil

% NS_E
</s>    sil

% CALL_V
PHONE    f ow n
CALL    k ao l

% DIAL_V
DIAL    d ay l

% NAME_N
STEVE    s t iy v
YOUNG    y ah ng

% DIGIT
FIVE    f ay v
FOUR    f ow r
NINE    n ay n
EIGHT    ey t
OH     ow
ONE    w ah n
SEVEN    s eh v ih n
SIX     s ih k s
THREE    th r iy
TWO    t uw
ZERO    z iy r ow

.grammar:

S: NS_B SENT NS_E
SENT: CALL_V NAME_N
SENT: DIAL_V DIGIT

But when I run mkdfa.pl sample I get the following error:

sample.grammar has 3 rules

sample.voca has 6 categories and 18 words

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Now parsing grammar file

"rror: Lexical mistake "

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no .dfa or .dict file generated