Complex sentence: The quotient R/(Z + αZ), for some irrational α, is the "irrational torus", a diffeological space diffeomorphic to the quotient of the regular 2-torus R 2/Z 2 by a line of slope α.
Split into simpler sentences: The quotient R/(Z + αZ), for some irrational α, is the "irrational torus". A diffeological space diffeomorphic to the quotient of the regular 2-torus R 2/Z 2 by a line of slope α.