use strict;
use warnings;

use Test::More tests => 4;
#use lib 'lib';

use_ok('Math::Symbolic');
use Math::Symbolic::ExportConstants qw/:all/;

my $var = Math::Symbolic::Variable->new();
my $a = $var->new('a' => 2);

print "Vars: a=" . $a->value() .
           " (Value is optional)\n\n";

my $const = Math::Symbolic::Constant->new();
my $ten   = $const->new(10);

my $op   = Math::Symbolic::Operator->new();
my $mul1 = $op->new('*', $a, $a);

my $exp = $op->new('^', $ten, $mul1);
ok(
	ref($exp) eq 'Math::Symbolic::Operator' &&
	$exp->type() == B_EXP,
	'Creation of exponentiation'
  );

print "Expression: 10^(a*a)\n\n";

print "prefix notation and evaluation:\n";
print $exp->to_string('prefix') . " = " . $exp->value() . "\n\n";

print "Now, we derive this partially to a: (prefix again)\n";

my $n_tree = $op->new( {
	type => U_P_DERIVATIVE,
	operands => [$exp, $a],
} );

print $n_tree->to_string('prefix') . " = " . $n_tree->value() . "\n\n";

print "Now, we apply the derivative to the term: (infix)\n";
$@ = undef;
my $derived;
eval <<'HERE';
$derived = $n_tree->apply_derivatives();
HERE
ok(!$@, 'apply_derivatives() did not complain');

print "$derived\n";

print "$derived = " . $derived->value() . "\n\n";

print "Finally, we simplify the derived term as much as possible:\n";

$@ = undef;
my $simplified;
eval <<'HERE';
$simplified = $derived->simplify();
HERE
ok(!$@, 'simplify() did not complain');

print "$simplified = " . $derived->value() . "\n\n";


