(* Title: HOL/BNF/BNF_Ctr_Sugar.thy
Author: Jasmin Blanchette, TU Muenchen
Copyright 2012
Wrapping existing freely generated type's constructors.
*)
header {* Wrapping Existing Freely Generated Type's Constructors *}
theory BNF_Ctr_Sugar
imports BNF_Util
keywords
"wrap_free_constructors" :: thy_goal and
"no_discs_sels" and
"rep_compat"
begin
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/bnf_ctr_sugar_tactics.ML"
ML_file "Tools/bnf_ctr_sugar.ML"
end