... học Thái Nguyên http://www.lrc-tnu.edu.vn 0 −→ N−→ N −→ N−→ 0 Tor Rn(M, N) −→ Tor Rn−1(M, N) n ≥ 0. . . −→ Tor Rn(M, N) −→ Tor Rn(M, N) −→ Tor Rn(M, N)−→ Tor Rn−1(M, ... x1A) −→ Tor Ri(R/I, 0 :Ax1) −→ Tor Ri(R/I, A); Tor Ri+1(R/I, A/x1A) −→ Tor Ri(R/I, x1A) −→ Tor Ri(R/I, A)−→ Tor Ri(R/I, A/x1A).x1A > sdim(A/x1A) s. dim (Tor Ri(R/I, ... Tor Rn−1(M, N) −→ Tor Rn−1(M, N) −→ Tor Rn−1(M, N). . . −→ Tor R1(M, N) −→ (M ⊗ N) −→ (M ⊗ N) −→ (M ⊗ N) −→ 0.M, N ExtnR(M, N) Tor Rn(M, N)nExt Tor Ext Tor S RS−1(ExtnR(M,...