  We analyze the causal-observational languages that were introduced in Barbero
and Sandu (2018), which allow discussing interventionist counterfactuals and
functional dependencies in a unified framework. In particular, we
systematically investigate the expressive power of these languages in causal
team semantics, and we provide complete natural deduction calculi for each
language. As an intermediate step towards the completeness, we axiomatize the
languages over a generalized version of causal team semantics, which turns out
to be interesting also in its own right.
