= Rational model of a collapsed complex projective subspace
The quotient $\mathbb{CP}^{5}/\mathbb{CP}^{2}$ is five-connected and has <cohomology> only in degrees $0,6,8,10$, with positive products zero. Its <minimal model> therefore starts with closed $a_6,b_8,c_{10}$; no decomposable differential can occur below degree twelve. Sending these three generators to the <cohomology> <basis> and all later generators to zero is a <chain map> and a <quasi-isomorphism>. Thus its full <minimal model> is the same as that of $S^6\vee S^8\vee S^{10}$. It starts with generators $u_{11},v_{13},w_{15},t_{15}$ satisfying $du=a^2,dv=ab,dw=ac,dt=b^2$, followed by generators killing remaining products and syzygies.
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