erlang 通过尾递归实现双层循环，并抽象出两向量的叉积的一般运算式

	-module(second).
	-export ([filter_map/5]).
	-export ([collect_sequence/3]).
	-export ([arithmetic/6]).
	-export ([arithmetic_list/4]).


	%% collect_sequence(Start_V,End_V,Result)
	%% 收集 Start_V~End_V 到结果Result中 区间[Start_V,End_V]
	%% Start_V - 左边界
	%% End_V - 右边界
	collect_sequence(Start_V,End_V,Result) -> if
		Start_V>End_V ->
			Result;
		true -> collect_sequence(Start_V,End_V-1,[End_V|Result])	
	end.
	% filter_map(X,Start_V,End_V,MapFun,FilterFun)
	filter_map(X,Start_V,End_V,MapFun,FilterFun) -> 
		Lst = collect_sequence(Start_V,End_V,[]),
		Lst1 = lists:filter(fun(Value) -> FilterFun(X,Value) end,Lst),
		lists:map(fun(Value)	-> MapFun(X,Value) end,Lst1).
	%arithmetic(A1,A2,B1,B2,MapFun,FilterFun)
	%根据算法F来计算两组数,比如计算[1~9] 和 [1~9] 的乘法口诀表
	%A1_Start 第一组开始值
	%A2_End 第一组终止值
	%B1_Start 第二组开始值
	%B2_Start 第二组终止值
	%F为算法 比如 fun(X,Y) -> X*Y end.
	%% 例子:arithmetic(1,9,1,9,fun(X,Y) -> X*Y end,fun(X,Y) ->X>=Y end).

	arithmetic(A1_Start,A2_End,B1_Start,B2_Start,MapFun,FilterFun) -> 
		if
			A1_Start>A2_End ->
				[];
			true ->
				io:format("~w~n",[filter_map(A1_Start,B1_Start,B2_Start,MapFun,FilterFun)]),
				arithmetic(A1_Start+1,A2_End,B1_Start,B2_Start,MapFun,FilterFun)
		end.
		

	filter_map_list(X,Lst2,MapFun,FilterFun) ->
		TempList = lists:filter(fun(Value) -> FilterFun(X,Value) end,Lst2),
		lists:map(fun(Value) -> MapFun(X,Value) end,TempList).

	%arithmetic_list - 通过 FilterFun,并且通过MapFun来将两个集合（向量）进行运算，
	%得到一个矩阵
	%参数:Lst1 - 第一个集合,Lst2 - 第二个集合,MapFun - 两个集合预算的函数,FilterFun 过滤函数
	%例子:
	%arithmetic_list([1,2,3,4,5,6,7,8,9],[1,2,3,4,5,6,7,8,9],fun(X,Y) ->X*Y end,fun(X,Y)->X>=Y end).

	arithmetic_list([],Lst2,MapFun,FilterFun) -> [];
	arithmetic_list(Lst1,Lst2,MapFun,FilterFun) ->
		[H|T] = Lst1,
		TempLst = filter_map_list(H,Lst2,MapFun,FilterFun),
		io:format("~w~n",[TempLst]),
		arithmetic_list(T,Lst2,MapFun,FilterFun).