“…According to Stasheff [23], we have a spectral sequence {E r } converging to H * (P 3X ), where the E 1 -term is given by E p,q 1 = (⊗ p IH * (X)) q ∼ = H q (X ∧ p ) for p 6 3 and E p,q 1 = 0 for p > 4 with the differentials d 1,q 1 = −φ and d 2,q 1 = −φ ⊗ 1 + 1 ⊗φ. Since H q (X ∧ 4 ) = 0 for q 6 23, we have 10 , v 12 , v 16 , v 18 , v 24 ] as an algebra for q 6 23, where…”