Parser: emit a warning on redundant "import"

bench/ce/algebraic_type.mlw

 module M
-  use import int.Int
+  use int.Int
 
   type int_type = Integer int
 

bench/ce/array_records.mlw

@@ -2,8 +2,8 @@
 
 module Array_records
 
-   use import int.Int
-   use import array.Array
+   use int.Int
+   use array.Array
 
    type value = int
    type index = int

bench/ce/arrays.mlw

 
 module A
 
-  use import int.Int
-  use import array.Array
+  use int.Int
+  use array.Array
 
   let f1 (a:array int) : int
   = a[0]
@@ -16,9 +16,9 @@ end
 
 module B
 
-  use import int.Int
-  use import array.Array
-  clone import array.Sorted with 
+  use int.Int
+  use array.Array
+  clone array.Sorted with 
     type elt=int,
     predicate le=(<=)
   

bench/ce/floats.mlw

 theory T32
 
-  use import ieee_float.Float32
+  use ieee_float.Float32
 
   goal g1 : forall x:t. eq x (0.0:t)
 
@@ -26,7 +26,7 @@ end
 
 theory T64
 
-  use import ieee_float.Float64
+  use ieee_float.Float64
 
   goal g1 : forall x:t. eq x (0.0:t)
 

bench/ce/if_decision_branch.mlw

 
 module Main
 
-  use import int.Int
+  use int.Int
 
   type path_sel_type = { mutable sel_path : bool}
 
@@ -12,8 +12,8 @@ end
 
 module Other
 
-  use import int.Int
-  use import Main
+  use int.Int
+  use Main
 
   let f (a : int)
     ensures {result = 5}

bench/ce/int.mlw

 theory T
 
-  use import int.Int
+  use int.Int
 
   goal g_lab : forall x [@model] :int. x >= 42 -> x + 3 <= 50
 

bench/ce/int32.mlw

 module Ce_int32
 
-  use import ref.Ref
+  use ref.Ref
   use export mach.int.Int32
 
   let dummy_update (r: ref int32)

bench/ce/int_overflow.mlw

 theory ModelInt
 
-use import int.Int
+use int.Int
 
 (* PASS *)
 goal test0 : forall x:int. not (0 < x < 1)
@@ -8,7 +8,7 @@ goal test0 : forall x:int. not (0 < x < 1)
 (* CE *)
 goal test1 : forall x:int. not (0 <= x <= 1)
 
-use import int.EuclideanDivision
+use int.EuclideanDivision
 
 (* CE *)
 goal test2 : forall x:int. div x x = 1

bench/ce/jlamp0.mlw

 module M
 
-  use import int.Int
-  use import ref.Ref
+  use int.Int
+  use ref.Ref
 
   val a : ref int
 

bench/ce/jlamp_array.mlw

 module Array
 
-  use import int.Int
-  use import array.Array
+  use int.Int
+  use array.Array
 
   type t
 

bench/ce/jlamp_projections.mlw

 
 module Abstract
 
-use import int.Int
+use int.Int
 
 type byte
 function to_int byte : int
@@ -18,7 +18,7 @@ val add (x y : byte) : byte
   requires { [@expl:integer overflow] in_range (to_int x + to_int y) }
   ensures { to_int result = to_int x + to_int y }
 
-use import ref.Ref
+use ref.Ref
 
 let p3 (a : ref byte) =
   a := add !a (of_int 1)
@@ -27,8 +27,8 @@ end
 
 module Record
 
-use import int.Int
-use import Abstract
+use int.Int
+use Abstract
 
 type r = {mutable f : byte; mutable g : bool}
 

bench/ce/list.mlw

 
 module List_int
 
-  use import int.Int
+  use int.Int
   
   type list = Nil | Cons int list
   
@@ -19,8 +19,8 @@ end
 
 module List_poly
 
-  use import list.List
-  use import list.Length
+  use list.List
+  use list.Length
   
   goal g1: forall l:list int. length l <> 0
 

bench/ce/map.mlw

 theory ModelMap
 
-use import map.Map
+use map.Map
 
 goal t1 : forall t:map int int, i : int.
    get (set t 0 42) i = get t i
@@ -9,9 +9,9 @@ end
 
 module M
 
-  use import int.Int
-  use import ref.Ref
-  use import map.Map
+  use int.Int
+  use ref.Ref
+  use map.Map
 
   let ghost test_map (ghost x : ref (map int int)) : unit
     ensures { !x[0] <> !x[1] }

bench/ce/real.mlw

 theory ModelReal
 
-use import real.Real
+use real.Real
 
 goal test1 : forall x:real. not (0.0 < x < 1.0)
 

bench/ce/record_map.mlw

 module M
 
-  use import map.Map
-  use import int.Int
+  use map.Map
+  use int.Int
 
   type r = {f [@model_trace:.field_f] :int; g:bool}
 

bench/ce/records.mlw

@@ -4,8 +4,8 @@
 
 module M
 
-  use import ref.Ref
-  use import int.Int
+  use ref.Ref
+  use int.Int
 
   (*** In all cases, records are decomposed using match eval ***)
 
@@ -49,7 +49,7 @@ end
 
 module Mutable
 
-  use import int.Int
+  use int.Int
 
 
   type r = {mutable f [@model_trace:.my_field_f] :int; mutable g:bool}

bench/ce/ref.mlw

 module M
-  use import ref.Ref
-  use import list.List
-  use import int.Int
+  use ref.Ref
+  use list.List
+  use int.Int
 
   let test_post (x: int) (y: ref int): unit
     ensures { old !y >= x }

bench/ce/result.mlw

 
 module M
 
-  use import int.Int
-  use import ref.Ref
+  use int.Int
+  use ref.Ref
 
   val a : ref int
 

bench/ce/simple_array.mlw

 theory ModelArray
 
-use import map.Map
+use map.Map
 
 goal t1 : forall t: map int int, i: int.
    get (set t 0 42) i = get t i

bench/invalid/arith.mlw

 
 module Arith
 
-  use import int.Int
+  use int.Int
 
   goal G1: 0 = 1
 
-  use import int.ComputerDivision
+  use int.ComputerDivision
 
   goal G2: div 1 0 = div 2 0