Counterfactual Transportability ID Algorithm

[cthoyt]

This is like ID* to general transportability (#122)

Counterfactual Transportability: A Formal Approach
J. Correa, S. Lee, E. Bareinboim.
ICML-22. In Proceedings of the 39th International Conference on Machine Learning.
Columbia CausalAI Laboratory, Technical Report (R-82), May, 2022. [pdf, bib]

[djinnome]

The notebook should first include the examples from the paper, and then additional examples if needed.