#	Lens Space (7,1) with left-handed twist
#
#	The entries in the generator matrix are
#
#		cos(2π/7) = 0.62348980185873353053 = root of 8x³ + 4x² - 4x - 1
#		sin(2π/7) = 0.78183148246802980871 = root of 64x⁶ - 112x⁴ + 56x² - 7
#
#	In principle we should be able to express these as elements
#	in a field Q[ξ], where ξ is a root of an irreducible polynomial,
#	but I don't immediately see how to do that.

  0.62348980185873353053 -0.78183148246802980871  0.00000000000000000000  0.00000000000000000000
  0.78183148246802980871  0.62348980185873353053  0.00000000000000000000  0.00000000000000000000
  0.00000000000000000000  0.00000000000000000000  0.62348980185873353053  0.78183148246802980871
  0.00000000000000000000  0.00000000000000000000 -0.78183148246802980871  0.62348980185873353053
