Before revision: For a given Markov process X and survival function  H on R_+, the \overline  inverse first-passage time problem (IFPT) is to find a barrier function b:
After revision: For a given Markov process X and survival function  H on R_+, the \overline H on \mathbb R^+, the inverse first-passage time problem (IFPT) is to find a barrier function b: