type variable = string

module VariableMap : Map.S with type key = variable

type t_exp =
    Integer of int
  | Boolean of bool
  | Variable of variable
  | Function of variable list * t_exp
  | Application of t_exp * t_exp list
  | Plus of t_exp * t_exp
  | Minus of t_exp * t_exp
  | Times of t_exp * t_exp
  | Division of t_exp * t_exp
  | Modulo of t_exp * t_exp
  | Power of t_exp * t_exp
  | PowerMod of t_exp * t_exp * t_exp
  | Rand of t_exp
  | BAnd of t_exp * t_exp
  | BOr of t_exp * t_exp
  | BNot of t_exp
  | Cmp of t_exp * t_exp
  | CmpLess of t_exp * t_exp
  | CmpLessEq of t_exp * t_exp
  | CmpGreater of t_exp * t_exp
  | CmpGreaterEq of t_exp * t_exp
  | IfThenElse of t_exp * t_exp * t_exp
  | LetIn of variable * t_exp * t_exp
  | LetFun of variable * variable list * t_exp * t_exp

type permittedValues =
    IntegerPermitted of int
  | BooleanPermitted of bool
  | FunctionPermitted of closure
and closure = {
  inputList: variable list;
  body: t_exp;
  assignments: permittedValues VariableMap.t;
  recursiveness: variable option
}

type memory = {
  assignments: permittedValues VariableMap.t
}

exception AbsentAssignment of string
exception WrongType of string
exception DivisionByZero of string
exception WrongAriety of string

val reduce : t_exp -> int -> int