  We provide an effective description of a particle-hole symmetric state of
electrons in a half-filled Landau level, starting from the traditional approach
pioneered by Halperin, Lee and Read. Specifically, we study a system consisting
of alternating quasi-one-dimensional strips of composite Fermi liquid (CFL) and
composite hole liquid (CHL), both of which break particle-hole symmetry. When
the CFL and CHL strips are identical in size, the resulting state is manifestly
invariant under the combined action of a particle-hole transformation with
respect to a single Landau level (which interchanges the CFL and CHL) and
translation by one unit, equal to the strip width, in the direction transverse
to the strips. At distances long compared to the strip width, we demonstrate
that the system is described by a Dirac fermion coupled to an emergent gauge
field, with an anti-unitary particle-hole symmetry, as recently proposed by
Son.
