###########################################################
#
#  Example showing how to use the Parser's function
#  answer checker.
#

DOCUMENT();        # This should be the first executable line in the problem.

loadMacros(
  "PGbasicmacros.pl",
  "PGanswermacros.pl",
  "Parser.pl",
  "parserUtils.pl",
);

TEXT(beginproblem());

###########################################################
#
#   The setup
#
$context = Context('Vector');
$context->variables->are(t=>'Real');
$context->constants->add(
  p0 => Point(pi,sqrt(2),3/exp(1)),
  v => Vector(exp(1),log(10),-(pi**2)),
);
$context->constants->set(v => {TeX => '\boldsymbol{v}'}); # make it print nicer

$L = Formula("p0+tv");
$v = Formula('v');

###########################################################
#
#  The problem text
#

Context()->texStrings;
BEGIN_TEXT

Suppose \(p_0\) is a point and \($v\) a vector in \(n\)-space.
$PAR
Then the vector-parametric form for the line through \(p_0\) in the
direction of \(v\) is$PAR
${BBLOCKQUOTE}
\(L(t)\) = \{ans_rule(30)\}.
${EBLOCKQUOTE}

END_TEXT
Context()->normalStrings;

###########################################################
#
#  The answers
#
ANS($L->cmp);

###########################################################

ENDDOCUMENT();        # This should be the last executable line in the problem.