## {4,4}, square 1S2b + square 1A2, solution 1
e2.
angleunit(pi/2)
# the line below lets us specify internal angles
angleofs(pi)
unittile(1,1,1,1)
unittile(1,1,1,1)
# the Conway notation
conway("(0 0')(1 1')(2')(3')(2 0')(3 1')")