1 theory Ex2

     2 imports Main

     3 begin

     4 

     5 section {* Proof context data *}

     6 

     7 ML {*

     8   structure My_Data = ProofDataFun(type T = int * string fun init _ = (2, "foo"))

     9 *}

    10 

    11 ML {* My_Data.get @{context} *}

    12 

    13 ML {* val ctxt0 = @{context} *}

    14 ML {* val ctxt1 = ctxt0 |> My_Data.map (fn (i, s) => (i + 1, s ^ "o")) *}

    15 ML {* val ctxt2 = ctxt1 |> My_Data.map (fn (i, s) => (i + 1, s ^ "o")) *}

    16 

    17 ML {* My_Data.get ctxt2 *}

    18 

    19 end