- renamed enum type class to spark_enum, to avoid confusion with enum type class defined in Enum theory - renamed theorem ..._card_UNIV to ..._card

use "Spec_Rules" for finding axioms -- more reliable and cleaner

optimize trivial equalities early in Nitpick -- it shouldn't be the job of the peephole optimizer

remove a few Nitpick calls in examples -- another step toward making them run faster

check arity of bound variables to avoid generating too large Kodkod problems -- an issue that arose in the context of TPTP/CASC

eliminated Codegen.mode in favour of explicit argument;

less bulky "_position", for improved readability of parse trees;

added more elementary Skip_Proof.make_thm_cterm;

explicit markup for loose bounds;

prefer internal types, via Simple_Syntax.read_typ;

eliminated obsolete Proof_Syntax.strip_sorts_consttypes;

split Type_Infer into early and late part, after Proof_Context; added Type_Infer_Context.const_sorts option, which allows NBE to use regular Syntax.check_term;