theory Ex2

imports Main

begin

section {* Simple methods *}

ML Method.setup

ML SIMPLE_METHOD'

ML SIMPLE_METHOD

method_setup my_method1 = {*

  Scan.succeed (K (SIMPLE_METHOD' (fn i: int => no_tac)))

*}  ""

method_setup my_method2 = {*

  Scan.succeed (fn ctxt: Proof.context =>

    SIMPLE_METHOD' (fn i: int => no_tac))

*}  ""

method_setup my_method3 = {*

  Attrib.thms >> (fn thms: thm list => fn ctxt: Proof.context =>

    SIMPLE_METHOD' (fn i: int => no_tac))

*}  ""

section {* My simplification method *}

ML {*

structure My_Simps = NamedThmsFun

(

  val name = "my_simp";

  val description = "My simp declaration";

)

*}

setup My_Simps.setup

method_setup my_simp = {*

  Scan.succeed (fn ctxt =>

    SIMPLE_METHOD' (fn i =>

      CHANGED (asm_full_simp_tac

        (HOL_basic_ss addsimps (My_Simps.get ctxt)) i)))

*} ""

lemma True

proof

  fix a b c

  assume [my_simp]: "a = b"

  assume [my_simp]: "b = c"

  have "a = c" by my_simp

qed

method_setup my_simp_all = {*

  Scan.succeed (fn ctxt =>

    SIMPLE_METHOD

      (CHANGED

        (ALLGOALS (asm_full_simp_tac

          (HOL_basic_ss addsimps (My_Simps.get ctxt))))))

*} ""

lemma True

proof

  fix a b c

  assume [my_simp]: "a = b"

  assume [my_simp]: "b = c"

  have "a = c" and "c = b" by my_simp_all

qed

end