Halfsquare
The left and inverted right halfsquares are inherently double (see double forms).
LEFT HALFSQUARE
P
RA
ORS
GREW
REXES
ESTATE
STONING
SILENTLY
EVERGREEN
SETSEYESON
RIGHT HALFSQUARE
S
BE
RIA
PERM
SARDS
SILENT
PALAVER
REREVISE
BIRDNESTS
SEAMSTRESS
INVERTED LEFT HALFSQUARE
GRAPHPAPER
RETRIEVER
ATWITTER
PRINTER
HITTER
PETER
AVER
PER
ER
R
INVERTED RIGHT HALFSQUARE
MAINFRAMES
ITERATIVE
EPISTLER
ESERINE
TRITON
STARE
ETON
EDE
DS
S