add lemmas rev_finite_subset, finite_vimageD, finite_vimage_iff
add lemmas rev_finite_subset, finite_vimageD, finite_vimage_iff

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