#n16. It has purely coclosed G2-structure


D.<e1,e2,e3,e4,e5,e6,f1,f2,f3,f4,f5,f6,g1,g2,g3,g4,g5,g6,h1,h2,h3,h4,h5,h6> = GradedCommutativeAlgebra(QQ)
N=D.cdg_algebra({})
N.inject_variables()
psie=e3*e4*e5+e1*e5*e6-e1*e2*e4+e2*e3*e6
psif=f3*f4*f5+f1*f5*f6-f1*f2*f4+f2*f3*f6
psig=g3*g4*g5+g1*g5*g6-g1*g2*g4+g2*g3*g6
psih=h3*h4*h5+h1*h5*h6-h1*h2*h4+h2*h3*h6
Cgfe=g1*f2*f3*e4*e5*e6+g1*f2*e3*f4*e5*e6+g1*f2*e3*e4*f5*e6+g1*f2*e3*e4*e5*f6+g1*e2*f3*f4*e5*e6+g1*e2*f3*e4*f5*e6+g1*e2*f3*e4*e5*f6+g1*e2*e3*f4*f5*e6+g1*e2*e3*f4*e5*f6+g1*e2*e3*e4*f5*f6+f1*g2*f3*e4*e5*e6+f1*g2*e3*f4*e5*e6+f1*g2*e3*e4*f5*e6+f1*g2*e3*e4*e5*f6+e1*g2*f3*f4*e5*e6+e1*g2*f3*e4*f5*e6+e1*g2*f3*e4*e5*f6+e1*g2*e3*f4*f5*e6+e1*g2*e3*f4*e5*f6+e1*g2*e3*e4*f5*f6+f1*f2*g3*e4*e5*e6+f1*e2*g3*f4*e5*e6+f1*e2*g3*e4*f5*e6+f1*e2*g3*e4*e5*f6+e1*f2*g3*f4*e5*e6+e1*f2*g3*e4*f5*e6+e1*f2*g3*e4*e5*f6+e1*e2*g3*f4*f5*e6+e1*e2*g3*f4*e5*f6+e1*e2*g3*e4*f5*f6+f1*f2*e3*g4*e5*e6+f1*e2*f3*g4*e5*e6+f1*e2*e3*g4*f5*e6+f1*e2*e3*g4*e5*f6+e1*f2*f3*g4*e5*e6+e1*f2*e3*g4*f5*e6+e1*f2*e3*g4*e5*f6+e1*e2*f3*g4*f5*e6+e1*e2*f3*g4*e5*f6+e1*e2*e3*g4*f5*f6+f1*f2*e3*e4*g5*e6+f1*e2*f3*e4*g5*e6+f1*e2*e3*f4*g5*e6+f1*e2*e3*e4*g5*f6+e1*f2*f3*e4*g5*e6+e1*f2*e3*f4*g5*e6+e1*f2*e3*e4*g5*f6+e1*e2*f3*f4*g5*e6+e1*e2*f3*e4*g5*f6+e1*e2*e3*f4*g5*f6+f1*f2*e3*e4*e5*g6+f1*e2*f3*e4*e5*g6+f1*e2*e3*f4*e5*g6+f1*e2*e3*e4*f5*g6+e1*f2*f3*e4*e5*g6+e1*f2*e3*f4*e5*g6+e1*f2*e3*e4*f5*g6+e1*e2*f3*f4*e5*g6+e1*e2*f3*e4*f5*g6+e1*e2*e3*f4*f5*g6
Cfgh=f1*g2*g3*h4*h5*h6+f1*g2*h3*g4*h5*h6+f1*g2*h3*h4*g5*h6+f1*g2*h3*h4*h5*g6+f1*h2*g3*g4*h5*h6+f1*h2*g3*h4*g5*h6+f1*h2*g3*h4*h5*g6+f1*h2*h3*g4*g5*h6+f1*h2*h3*g4*h5*g6+f1*h2*h3*h4*g5*g6+g1*f2*g3*h4*h5*h6+g1*f2*h3*g4*h5*h6+g1*f2*h3*h4*g5*h6+g1*f2*h3*h4*h5*g6+h1*f2*g3*g4*h5*h6+h1*f2*g3*h4*g5*h6+h1*f2*g3*h4*h5*g6+h1*f2*h3*g4*g5*h6+h1*f2*h3*g4*h5*g6+h1*f2*h3*h4*g5*g6+g1*g2*f3*h4*h5*h6+g1*h2*f3*g4*h5*h6+g1*h2*f3*h4*g5*h6+g1*h2*f3*h4*h5*g6+h1*g2*f3*g4*h5*h6+h1*g2*f3*h4*g5*h6+h1*g2*f3*h4*h5*g6+h1*h2*f3*g4*g5*h6+h1*h2*f3*g4*h5*g6+h1*h2*f3*h4*g5*g6+g1*g2*h3*f4*h5*h6+g1*h2*g3*f4*h5*h6+g1*h2*h3*f4*g5*h6+g1*h2*h3*f4*h5*g6+h1*g2*g3*f4*h5*h6+h1*g2*h3*f4*g5*h6+h1*g2*h3*f4*h5*g6+h1*h2*g3*f4*g5*h6+h1*h2*g3*f4*h5*g6+h1*h2*h3*f4*g5*g6+g1*g2*h3*h4*f5*h6+g1*h2*g3*h4*f5*h6+g1*h2*h3*g4*f5*h6+g1*h2*h3*h4*f5*g6+h1*g2*g3*h4*f5*h6+h1*g2*h3*g4*f5*h6+h1*g2*h3*h4*f5*g6+h1*h2*g3*g4*f5*h6+h1*h2*g3*h4*f5*g6+h1*h2*h3*g4*f5*g6+g1*g2*h3*h4*h5*f6+g1*h2*g3*h4*h5*f6+g1*h2*h3*g4*h5*f6+g1*h2*h3*h4*g5*f6+h1*g2*g3*h4*h5*f6+h1*g2*h3*g4*h5*f6+h1*g2*h3*h4*g5*f6+h1*h2*g3*g4*h5*f6+h1*h2*g3*h4*g5*f6+h1*h2*h3*g4*g5*f6
(-1/6)*psie*Cgfe*psif*psih*Cfgh*psig


D.<e1,e2,e3,e4,e5,e6,f1,f2,f3,f4,f5,f6,g1,g2,g3,g4,g5,g6,h1,h2,h3,h4,h5,h6,x1,x2,x3,x4,x5,x6,y1,y2,y3,y4,y5,y6,z1,z2,z3,z4,z5,z6> = GradedCommutativeAlgebra(QQ)
N=D.cdg_algebra({})
N.inject_variables()
psie=e3*e4*e5+e1*e5*e6-e1*e2*e4+e2*e3*e6
psif=f3*f4*f5+f1*f5*f6-f1*f2*f4+f2*f3*f6
psig=g3*g4*g5+g1*g5*g6-g1*g2*g4+g2*g3*g6
psix=x3*x4*x5+x1*x5*x6-x1*x2*x4+x2*x3*x6
psiy=y3*y4*y5+y1*y5*y6-y1*y2*y4+y2*y3*y6
psiz=z3*z4*z5+z1*z5*z6-z1*z2*z4+z2*z3*z6
psixyz=x3*y4*z5+x1*y5*z6-x1*y2*z4+x2*y3*z6
Chxe=h1*x2*x3*e4*e5*e6+h1*x2*e3*x4*e5*e6+h1*x2*e3*e4*x5*e6+h1*x2*e3*e4*e5*x6+h1*e2*x3*x4*e5*e6+h1*e2*x3*e4*x5*e6+h1*e2*x3*e4*e5*x6+h1*e2*e3*x4*x5*e6+h1*e2*e3*x4*e5*x6+h1*e2*e3*e4*x5*x6+x1*h2*x3*e4*e5*e6+x1*h2*e3*x4*e5*e6+x1*h2*e3*e4*x5*e6+x1*h2*e3*e4*e5*x6+e1*h2*x3*x4*e5*e6+e1*h2*x3*e4*x5*e6+e1*h2*x3*e4*e5*x6+e1*h2*e3*x4*x5*e6+e1*h2*e3*x4*e5*x6+e1*h2*e3*e4*x5*x6+x1*x2*h3*e4*e5*e6+x1*e2*h3*x4*e5*e6+x1*e2*h3*e4*x5*e6+x1*e2*h3*e4*e5*x6+e1*x2*h3*x4*e5*e6+e1*x2*h3*e4*x5*e6+e1*x2*h3*e4*e5*x6+e1*e2*h3*x4*x5*e6+e1*e2*h3*x4*e5*x6+e1*e2*h3*e4*x5*x6+x1*x2*e3*h4*e5*e6+x1*e2*x3*h4*e5*e6+x1*e2*e3*h4*x5*e6+x1*e2*e3*h4*e5*x6+e1*x2*x3*h4*e5*e6+e1*x2*e3*h4*x5*e6+e1*x2*e3*h4*e5*x6+e1*e2*x3*h4*x5*e6+e1*e2*x3*h4*e5*x6+e1*e2*e3*h4*x5*x6+x1*x2*e3*e4*h5*e6+x1*e2*x3*e4*h5*e6+x1*e2*e3*x4*h5*e6+x1*e2*e3*e4*h5*x6+e1*x2*x3*e4*h5*e6+e1*x2*e3*x4*h5*e6+e1*x2*e3*e4*h5*x6+e1*e2*x3*x4*h5*e6+e1*e2*x3*e4*h5*x6+e1*e2*e3*x4*h5*x6+x1*x2*e3*e4*e5*h6+x1*e2*x3*e4*e5*h6+x1*e2*e3*x4*e5*h6+x1*e2*e3*e4*x5*h6+e1*x2*x3*e4*e5*h6+e1*x2*e3*x4*e5*h6+e1*x2*e3*e4*x5*h6+e1*e2*x3*x4*e5*h6+e1*e2*x3*e4*x5*h6+e1*e2*e3*x4*x5*h6
Chyf=h1*y2*y3*f4*f5*f6+h1*y2*f3*y4*f5*f6+h1*y2*f3*f4*y5*f6+h1*y2*f3*f4*f5*y6+h1*f2*y3*y4*f5*f6+h1*f2*y3*f4*y5*f6+h1*f2*y3*f4*f5*y6+h1*f2*f3*y4*y5*f6+h1*f2*f3*y4*f5*y6+h1*f2*f3*f4*y5*y6+y1*h2*y3*f4*f5*f6+y1*h2*f3*y4*f5*f6+y1*h2*f3*f4*y5*f6+y1*h2*f3*f4*f5*y6+f1*h2*y3*y4*f5*f6+f1*h2*y3*f4*y5*f6+f1*h2*y3*f4*f5*y6+f1*h2*f3*y4*y5*f6+f1*h2*f3*y4*f5*y6+f1*h2*f3*f4*y5*y6+y1*y2*h3*f4*f5*f6+y1*f2*h3*y4*f5*f6+y1*f2*h3*f4*y5*f6+y1*f2*h3*f4*f5*y6+f1*y2*h3*y4*f5*f6+f1*y2*h3*f4*y5*f6+f1*y2*h3*f4*f5*y6+f1*f2*h3*y4*y5*f6+f1*f2*h3*y4*f5*y6+f1*f2*h3*f4*y5*y6+y1*y2*f3*h4*f5*f6+y1*f2*y3*h4*f5*f6+y1*f2*f3*h4*y5*f6+y1*f2*f3*h4*f5*y6+f1*y2*y3*h4*f5*f6+f1*y2*f3*h4*y5*f6+f1*y2*f3*h4*f5*y6+f1*f2*y3*h4*y5*f6+f1*f2*y3*h4*f5*y6+f1*f2*f3*h4*y5*y6+y1*y2*f3*f4*h5*f6+y1*f2*y3*f4*h5*f6+y1*f2*f3*y4*h5*f6+y1*f2*f3*f4*h5*y6+f1*y2*y3*f4*h5*f6+f1*y2*f3*y4*h5*f6+f1*y2*f3*f4*h5*y6+f1*f2*y3*y4*h5*f6+f1*f2*y3*f4*h5*y6+f1*f2*f3*y4*h5*y6+y1*y2*f3*f4*f5*h6+y1*f2*y3*f4*f5*h6+y1*f2*f3*y4*f5*h6+y1*f2*f3*f4*y5*h6+f1*y2*y3*f4*f5*h6+f1*y2*f3*y4*f5*h6+f1*y2*f3*f4*y5*h6+f1*f2*y3*y4*f5*h6+f1*f2*y3*f4*y5*h6+f1*f2*f3*y4*y5*h6
Chzg=h1*z2*z3*g4*g5*g6+h1*z2*g3*z4*g5*g6+h1*z2*g3*g4*z5*g6+h1*z2*g3*g4*g5*z6+h1*g2*z3*z4*g5*g6+h1*g2*z3*g4*z5*g6+h1*g2*z3*g4*g5*z6+h1*g2*g3*z4*z5*g6+h1*g2*g3*z4*g5*z6+h1*g2*g3*g4*z5*z6+z1*h2*z3*g4*g5*g6+z1*h2*g3*z4*g5*g6+z1*h2*g3*g4*z5*g6+z1*h2*g3*g4*g5*z6+g1*h2*z3*z4*g5*g6+g1*h2*z3*g4*z5*g6+g1*h2*z3*g4*g5*z6+g1*h2*g3*z4*z5*g6+g1*h2*g3*z4*g5*z6+g1*h2*g3*g4*z5*z6+z1*z2*h3*g4*g5*g6+z1*g2*h3*z4*g5*g6+z1*g2*h3*g4*z5*g6+z1*g2*h3*g4*g5*z6+g1*z2*h3*z4*g5*g6+g1*z2*h3*g4*z5*g6+g1*z2*h3*g4*g5*z6+g1*g2*h3*z4*z5*g6+g1*g2*h3*z4*g5*z6+g1*g2*h3*g4*z5*z6+z1*z2*g3*h4*g5*g6+z1*g2*z3*h4*g5*g6+z1*g2*g3*h4*z5*g6+z1*g2*g3*h4*g5*z6+g1*z2*z3*h4*g5*g6+g1*z2*g3*h4*z5*g6+g1*z2*g3*h4*g5*z6+g1*g2*z3*h4*z5*g6+g1*g2*z3*h4*g5*z6+g1*g2*g3*h4*z5*z6+z1*z2*g3*g4*h5*g6+z1*g2*z3*g4*h5*g6+z1*g2*g3*z4*h5*g6+z1*g2*g3*g4*h5*z6+g1*z2*z3*g4*h5*g6+g1*z2*g3*z4*h5*g6+g1*z2*g3*g4*h5*z6+g1*g2*z3*z4*h5*g6+g1*g2*z3*g4*h5*z6+g1*g2*g3*z4*h5*z6+z1*z2*g3*g4*g5*h6+z1*g2*z3*g4*g5*h6+z1*g2*g3*z4*g5*h6+z1*g2*g3*g4*z5*h6+g1*z2*z3*g4*g5*h6+g1*z2*g3*z4*g5*h6+g1*z2*g3*g4*z5*h6+g1*g2*z3*z4*g5*h6+g1*g2*z3*g4*z5*h6+g1*g2*g3*z4*z5*h6
psie*Chxe*psix*psif*Chyf*psiy*psig*Chzg*psiz*psixyz

#psiplus=c*(x2*x3*x4-x1*x4*x5+x1*x2*x6+x3*x5*x6)


D.<e1,e2,e3,e4,e5,e6,f1,f2,f3,f4,f5,f6,x1,x2,x3,x4,x5,x6> = GradedCommutativeAlgebra(QQ,degrees=(1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2))
N=D.cdg_algebra({})
N.inject_variables()
psie=e3*e4*e5+e1*e5*e6-e1*e2*e4+e2*e3*e6
psif=f3*f4*f5+f1*f5*f6-f1*f2*f4+f2*f3*f6
omegaxf=(3*x1*f3-x2*f5-x4*f6+x1*f6+x3*f4+x1*f4-x3*f6)-(3*f1*x3-f2*x5-f4*x6+f1*x6+f3*x4+f1*x4-f3*x6)
Cxfe=x1*f2*f3*e4*e5*e6+x1*f2*e3*f4*e5*e6+x1*f2*e3*e4*f5*e6+x1*f2*e3*e4*e5*f6+x1*e2*f3*f4*e5*e6+x1*e2*f3*e4*f5*e6+x1*e2*f3*e4*e5*f6+x1*e2*e3*f4*f5*e6+x1*e2*e3*f4*e5*f6+x1*e2*e3*e4*f5*f6-x2*f1*f3*e4*e5*e6-x2*f1*e3*f4*e5*e6-x2*f1*e3*e4*f5*e6-x2*f1*e3*e4*e5*f6-x2*e1*f3*f4*e5*e6-x2*e1*f3*e4*f5*e6-x2*e1*f3*e4*e5*f6-x2*e1*e3*f4*f5*e6-x2*e1*e3*f4*e5*f6-x2*e1*e3*e4*f5*f6+x3*f1*f2*e4*e5*e6+x3*f1*e2*f4*e5*e6+x3*f1*e2*e4*f5*e6+x3*f1*e2*e4*e5*f6+x3*e1*f2*f4*e5*e6+x3*e1*f2*e4*f5*e6+x3*e1*f2*e4*e5*f6+x3*e1*e2*f4*f5*e6+x3*e1*e2*f4*e5*f6+x3*e1*e2*e4*f5*f6-x4*f1*f2*e3*e5*e6-x4*f1*e2*f3*e5*e6-x4*f1*e2*e3*f5*e6-x4*f1*e2*e3*e5*f6-x4*e1*f2*f3*e5*e6-x4*e1*f2*e3*f5*e6-x4*e1*f2*e3*e5*f6-x4*e1*e2*f3*f5*e6-x4*e1*e2*f3*e5*f6-x4*e1*e2*e3*f5*f6+x5*f1*f2*e3*e4*e6+x5*f1*e2*f3*e4*e6+x5*f1*e2*e3*f4*e6+x5*f1*e2*e3*e4*f6+x5*e1*f2*f3*e4*e6+x5*e1*f2*e3*f4*e6+x5*e1*f2*e3*e4*f6+x5*e1*e2*f3*f4*e6+x5*e1*e2*f3*e4*f6+x5*e1*e2*e3*f4*f6-x6*f1*f2*e3*e4*e5-x6*f1*e2*f3*e4*e5-x6*f1*e2*e3*f4*e5-x6*f1*e2*e3*e4*f5-x6*e1*f2*f3*e4*e5-x6*e1*f2*e3*f4*e5-x6*e1*f2*e3*e4*f5-x6*e1*e2*f3*f4*e5-x6*e1*e2*f3*e4*f5-x6*e1*e2*e3*f4*f5
1/2*psie*Cxfe*psif*omegaxf

# 3x1^2 - 2x1*x4 + 2x1*x6 + x2^2 + 3x3^2 + 2x3*x4 + 2x3*x6 + x4^2 + x5^2 + x6^2
# [3,0,0,-1,0,1],[0,1,0,0,0,0],[0,0,3,1,0,1],[-1,0,1,1,0,0],[0,0,0,0,1,0],[1,0,1,0,0,1]
# The metric is positive definite


A.<x1,x2,x3,x4,x5,x6,x7> = GradedCommutativeAlgebra(QQ)
M=A.cdg_algebra({ x4:x1*x2, x5: x1*x4,x6:x1*x5 })
M.inject_variables()
omega=3*x1*x3-x2*x5-x4*x6+x1*x6+x3*x4+x1*x4-x3*x6
psi=(-x1*x6+x3*x4)*x5+(x1*x4+x3*x6)*x2
psiplus=x2*x3*x4-x1*x4*x5+x1*x2*x6+x3*x5*x6
eta=x7-x5
omega*psi
psi*psiplus-(2/3)*omega^3
psi.differential()
omega*omega.differential()-psi*eta.differential()
omega^2*eta.differential()+2*psiplus*omega.differential()