Eigenstates, baby! ;-)

use Quantum::Superpositions;
@a = qw(-true -depth=1);
@b = qw(-search -depth=1 -true -expand_all...);
@c = qw(-true -depth=1 -height);

print "right" unless eigenstates(any(@a) ne all(@b));
print "wrong" unless eigenstates(any(@c) ne all(@b));
[download]

Output:

right
[download]