Preservativity logic: An analogue of interpretability logic for constructive theories.

Rosalie Iemhoff Preservativity logic: An analogue of interpretability logic for constructive theories. 230-249 2003 49 Math. Log. Q. 3 http://dx.doi.org/10.1002/malq.200310023 db/journals/mlq/mlq49.html#Iemhoff03