  Suppose that A and B are unital Banach algebras with units 1_A and 1_B,
respectively, M is a unital Banach A-B-bimodule, T=Tri(A,M,B) is the triangular
Banach algebra, X is a unital T-bimodule, X_{AA}=1_AX1_A, X_{BB}=1_BX1_B,
X_{AB}=1_AX1_B and X_{BA}=1_BX1_A. Applying two nice long exact sequences
related to A, B, T, X, X_{AA}, X_{BB}, X_{AB} and X_{BA} we establish some
results on (co)homology of triangular Banach algebras.
