let rec eval_stmt env s =

	match s with

	| NoOp -> env

	| Seq(s1,s2) ->
		let updated_environment = eval_stmt env s1 in
		let updated_environment2 = eval_stmt updated_environment s2 in
		(* Return updated environment *)
		updated_environment2


	| Declare(d1,s)-> (s, Val_Int 0) :: env
	(* TO DO *)

	| Assign(s,e) -> (s, eval_expr env e)::env

	| If(g,b,e) ->

		let Val_Bool n1 = eval_expr env g in

		if n1 then eval_stmt env b else eval_stmt env e

	| Print(e) -> let v = eval_expr env e in
		match v with
		| Val_Int i  ->  print_output_int i;  env
		| Val_Bool b ->  print_output_bool b; env;;

	| While(g,body) -> let v = eval_expr env g in
		match v with
		| Val_Int i  -> raise (TypeError)
		| Val_Bool b -> if b then eval_stmt env b else env