add legacy target for HOL-Probability, needed by AFP/Markov_Models
add legacy target for HOL-Probability, needed by AFP/Markov_Models

MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle