added the lemmas supp_char and supp_string

added some lemmas to the collection "abs_fresh" the lemmas are of the form finite (supp x) ==> (b # [a].x) = (b=a \/ b # x) previously only lemmas of the form (b # [a].x) = (b=a \/ b # x) with the type-constraint that x is finitely supported were included.

_E suffix for compatibility with AddIffs

tidied

simplified the special-case simprules

theorems need names

commented the transitivity and narrowing proof

Theory specifications --- with type-inference, but no internal polymorphism.

added infer_type, declared_type;

added param, spec, named_spec;

added init; tuned signature;

added 'axiomatization';

Specification.pretty_consts;

gen_names: preserve empty names;

added Isar/specification.ML;

updated;

another change for the new induct-method

RuleCases.make_nested;

support nested cases; tuned apply_case;

support nested cases; added apply_case; replaced make/simple by make_common/nested/simple;

RuleCases.make_common;

pretty_locale: backquote notes;

RuleCases.make_simple;

tuned order;

added backquote;

RuleCases.make_common/nested;

* Provers/induct: improved simultaneous goals -- nested cases;

added private datatype nprod (copy of prod) to be used in the induction rule

changed PRO_RED proof to conform with the new induction rules

prep_meta_eq: reuse mk_rews of local simpset; adapted ML code to common conventions; tuned;