(*  Title:      HOL/Ctr_Sugar.thy

    Author:     Jasmin Blanchette, TU Muenchen

    Copyright   2012, 2013

Wrapping existing freely generated type's constructors.

*)

header {* Wrapping Existing Freely Generated Type's Constructors *}

theory Ctr_Sugar

imports HOL

keywords

  "print_case_translations" :: diag and

  "wrap_free_constructors" :: thy_goal

begin

consts

  case_guard :: "bool \<Rightarrow> 'a \<Rightarrow> ('a \<Rightarrow> 'b) \<Rightarrow> 'b"

  case_nil :: "'a \<Rightarrow> 'b"

  case_cons :: "('a \<Rightarrow> 'b) \<Rightarrow> ('a \<Rightarrow> 'b) \<Rightarrow> 'a \<Rightarrow> 'b"

  case_elem :: "'a \<Rightarrow> 'b \<Rightarrow> 'a \<Rightarrow> 'b"

  case_abs :: "('c \<Rightarrow> 'b) \<Rightarrow> 'b"

declare [[coercion_args case_guard - + -]]

declare [[coercion_args case_cons - -]]

declare [[coercion_args case_abs -]]

declare [[coercion_args case_elem - +]]

ML_file "Tools/case_translation.ML"

setup Case_Translation.setup

lemma iffI_np: "\<lbrakk>x \<Longrightarrow> \<not> y; \<not> x \<Longrightarrow> y\<rbrakk> \<Longrightarrow> \<not> x \<longleftrightarrow> y"

by (erule iffI) (erule contrapos_pn)

lemma iff_contradict:

"\<not> P \<Longrightarrow> P \<longleftrightarrow> Q \<Longrightarrow> Q \<Longrightarrow> R"

"\<not> Q \<Longrightarrow> P \<longleftrightarrow> Q \<Longrightarrow> P \<Longrightarrow> R"

by blast+

ML_file "Tools/ctr_sugar_util.ML"

ML_file "Tools/ctr_sugar_tactics.ML"

ML_file "Tools/ctr_sugar_code.ML"

ML_file "Tools/ctr_sugar.ML"

end