How to define a binary variable in docplex?

Question

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y_kl = 1, if part k precedes part l in the processing sequence; otherwise y_kl = 0 (sequencing variable)

I have defined the binary variable y as:

y1 = [(k,l) for k in range(K) for l in range(K)]
y = m.binary_var_dict(y1, name="y")

However, idk if it is correct since k<l, how to add it?