+ let analyze x =
+ let module M = MathQL in
+ let rec join l1 l2 = match l1, l2 with
+ | [], _ -> l2
+ | _, [] -> l1
+ | s1 :: tl1, s2 :: _ when s1 < s2 -> s1 :: join tl1 l2
+ | s1 :: _, s2 :: tl2 when s2 < s1 -> s2 :: join l1 tl2
+ | s1 :: tl1, s2 :: tl2 -> s1 :: join tl1 tl2
+ in
+ let rec an_val = function
+ | M.Const _ -> []
+ | M.VVar _ -> []
+ | M.Record (rv, _) -> [rv]
+ | M.Fun (_, x) -> an_val x
+ | M.Attribute (_, _, x) -> an_val x
+ | M.RefOf x -> an_set x
+ and an_boole = function
+ | M.False -> []
+ | M.True -> []
+ | M.Ex _ _ -> []
+ | M.Not x -> an_boole x
+ | M.And (x, y) -> join (an_boole x) (an_boole y)
+ | M.Or (x, y) -> join (an_boole x) (an_boole y)
+ | M.Sub (x, y) -> join (an_val x) (an_val y)
+ | M.Meet (x, y) -> join (an_val x) (an_val y)
+ | M.Eq (x, y) -> join (an_val x) (an_val y)
+ and an_set = function
+ | M.SVar _ -> []
+ | M.RVar _ -> []
+ | M.Relation (_, _, x, _) -> an_set x
+ | M.Pattern x -> an_val x
+ | M.Ref x -> an_val x
+ | M.Union (x, y) -> join (an_set x) (an_set y)
+ | M.Intersect (x, y) -> join (an_set x) (an_set y)
+ | M.Diff (x, y) -> join (an_set x) (an_set y)
+ | M.LetSVar (_, x, y) -> join (an_set x) (an_set y)
+ | M.LetVVar (_, x, y) -> join (an_val x) (an_set y)
+ | M.Select (_, x, y) -> join (an_set x) (an_boole y)
+ in
+ an_boole x