(* Title: Pure/morphism.ML
Author: Makarius
Abstract morphisms on formal entities.
*)
infix 1 $>
signature BASIC_MORPHISM =
sig
type morphism
type declaration = morphism -> Context.generic -> Context.generic
val $> : morphism * morphism -> morphism
end
signature MORPHISM =
sig
include BASIC_MORPHISM
val binding: morphism -> binding -> binding
val typ: morphism -> typ -> typ
val term: morphism -> term -> term
val fact: morphism -> thm list -> thm list
val thm: morphism -> thm -> thm
val cterm: morphism -> cterm -> cterm
val morphism:
{binding: binding -> binding,
typ: typ -> typ,
term: term -> term,
fact: thm list -> thm list} -> morphism
val binding_morphism: (binding -> binding) -> morphism
val typ_morphism: (typ -> typ) -> morphism
val term_morphism: (term -> term) -> morphism
val fact_morphism: (thm list -> thm list) -> morphism
val thm_morphism: (thm -> thm) -> morphism
val identity: morphism
val compose: morphism -> morphism -> morphism
val transform: morphism -> (morphism -> 'a) -> morphism -> 'a
val form: (morphism -> 'a) -> 'a
end;
structure Morphism: MORPHISM =
struct
datatype morphism = Morphism of
{binding: binding -> binding,
typ: typ -> typ,
term: term -> term,
fact: thm list -> thm list};
type declaration = morphism -> Context.generic -> Context.generic;
fun binding (Morphism {binding, ...}) = binding;
fun typ (Morphism {typ, ...}) = typ;
fun term (Morphism {term, ...}) = term;
fun fact (Morphism {fact, ...}) = fact;
val thm = singleton o fact;
val cterm = Drule.cterm_rule o thm;
val morphism = Morphism;
fun binding_morphism binding = morphism {binding = binding, typ = I, term = I, fact = I};
fun typ_morphism typ = morphism {binding = I, typ = typ, term = I, fact = I};
fun term_morphism term = morphism {binding = I, typ = I, term = term, fact = I};
fun fact_morphism fact = morphism {binding = I, typ = I, term = I, fact = fact};
fun thm_morphism thm = morphism {binding = I, typ = I, term = I, fact = map thm};
val identity = morphism {binding = I, typ = I, term = I, fact = I};
fun compose
(Morphism {binding = binding1, typ = typ1, term = term1, fact = fact1})
(Morphism {binding = binding2, typ = typ2, term = term2, fact = fact2}) =
morphism {binding = binding1 o binding2, typ = typ1 o typ2,
term = term1 o term2, fact = fact1 o fact2};
fun phi1 $> phi2 = compose phi2 phi1;
fun transform phi f = fn psi => f (phi $> psi);
fun form f = f identity;
end;
structure BasicMorphism: BASIC_MORPHISM = Morphism;
open BasicMorphism;