  Degree-$d$-invariant laminations of the disk model the dynamical action of a
degree-$d$ polynomial; such a lamination defines an equivalence relation on
$S^1$ that corresponds to dynamical rays of an associated polynomial landing at
the same multi-accessible points in the Julia set. Primitive majors are certain
subsets of degree-$d$-invariant laminations consisting of critical leaves and
gaps. The space $\textrm{PM}(d)$ of primitive degree-$d$ majors is a spine for
the set of monic degree-$d$ polynomials with distinct roots and serves as a
parameterization of a subset of the boundary of the connectedness locus for
degree-$d$ polynomials. The core entropy of a postcritically finite polynomial
is the topological entropy of the action of the polynomial on the associated
Hubbard tree. Core entropy may be computed directly, bypassing the Hubbard
tree, using a combinatorial analogue of the Hubbard tree within the context of
degree-$d$-invariant laminations.
