/***the six rank 4 \vartheta-lattices with respect to \Q(\sqrt{-67})***/ S:=QuadraticField(-67); Gram1:=1/67*Matrix(S,[ [ 134 , 0 , 20*w , 20*w ], [ 0 , 134 , 20*w , -20*w ], [ -20*w , -20*w , 402 , 0 ], [ -20*w , 20*w , 0 , 402 ] ]); Gram2:=1/67*Matrix(S,[ [ 19832 , 260*w + 16884 , 334*w + 134 , 1417*w + 737 ], [ -260*w + 16884 , 14606 , 282*w + 402 , 1196*w + 1876 ], [ -334*w + 134 , -282*w + 402 , 402 , 1608 ], [ -1417*w + 737 , -1196*w + 1876 , 1608 , 6834 ] ]); Gram3:=1/67*Matrix(S,[ [ 19832 , 506*w - 134 , 100*w + 11256 , 1417*w + 737 ], [ -506*w - 134 , 1072 , -321*w + 201 , -20*w + 2412 ], [ -100*w + 11256 , 321*w + 201 , 6834 , 804*w + 804 ], [ -1417*w + 737 , 20*w + 2412 , -804*w + 804 , 6834 ] ]); Gram4:=1/67*Matrix(S,[ [ 10184 , -645*w - 1005 , -100*w + 12060 , -995*w - 1675 ], [ 645*w - 1005 , 3082 , 749*w - 469 , -20*w + 4422 ], [ 100*w + 12060 , -749*w - 469 , 14874 , -1206*w - 1206 ], [ 995*w - 1675 , 20*w + 4422 , 1206*w - 1206 , 6834 ] ]); Gram5:=1/67*Matrix(S,[ [ 134 , -27*w + 67 , 13*w + 67 , 804 ], [ 27*w + 67 , 536 , 40*w - 402 , 191*w + 871 ], [ -13*w + 67 , -40*w - 402 , 804 , -201*w - 201 ], [ 804 , -191*w + 871 , 201*w - 201 , 6834 ] ]); Gram6:=1/67*Matrix(S,[ [ 2010 , -95*w - 603 , -196*w - 536 , 258*w + 670 ], [ 95*w - 603 , 3484 , 308*w - 1206 , 102*w + 268 ], [ 196*w - 536 , -308*w - 1206 , 4422 , -219*w - 1809 ], [ -258*w + 670 , -102*w + 268 , 219*w - 1809 , 3484 ] ]);