it fixes the issue Since you didn't specify the input format, I'm assuming that 0 is the initial state, any integers that appear in the second column but not the first are accepting states (3 for T1 and 2 for T2), and each row is an element of the transition relation, giving the the previous state, the next state, the input letter and the output letter.

Any operation on FSTs needs to produce a new FST, so we need states, an input alphabet, an output alphabet, initial states, final states and a transition relation (the specifications of the FSTs A, B and W below are given in this order). Suppose our FSTs are:

A = (Q, Σ, Γ, Q_{0}, Q_{F}, α)
B = (P, Γ, Δ, P_{0}, P_{F}, β)

W = (R, Σ, Δ, R_{0}, R_{F}, ω) = A ∘ B

R = Q × P

R = {(0,0), (0,1), ... (3, 2)}

R = {00, 01, 02, 10, 11, 12, 20, 21, 22, 30, 31, 32}

R_{0} = Q_{0} × P_{0}
R_{F} = Q_{F} × P_{F}

ω = { ((q_{i},p_{h}), σ) → ((q_{j}, p_{k}), δ) : (q_{i}, σ) → (q_{j}, γ) ∈ α,
(p_{h}, γ) → (p_{k}, δ) ∈ β}

00 11 a : a
01 12 a : a