replaced foldl_XXX by canonical fold_XXX; canonical arguments for add_term_varnames, add_tvarsT, add_tvars, add_vars, add_frees,
replaced foldl_XXX by canonical fold_XXX;
canonical arguments for add_term_varnames, add_tvarsT, add_tvars, add_vars, add_frees,

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