find_consts: fold in preference to foldl; hide internal constants; remove redundant exception catch
find_consts: fold in preference to foldl; hide internal constants; remove redundant exception catch

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