I am getting error in back test

Algos, strategies, code
1

BUY:

SET A = 1
SET A = LOOP(A,1,1,0,ADD)
SET B = LOOP(ATR,A,1,1,MULTIPLY)
SET ATR = LOOP(B,TR(),0,0,ADD)/A
SET ATR14 = IF(A=14,ATR,0)
SET ST1 = (HIGH + LOW)/2 + 3ATR14
SET ST2 = (HIGH + LOW)/2 - 3ATR14
SET MA1 = EMA(CLOSE,10)
SET MA2 = SMA(CLOSE,50)
SET R = RSI(CLOSE,10)
SET ST = IF(TREND(CLOSE)=UP,ST1,ST2)
CLOSE>MA2 AND CLOSE>ST AND MA1>ST AND TREND(ST)=UP AND R<70

SELL:

SET A = 1
SET A = LOOP(A,1,1,0,ADD)
SET B = LOOP(ATR,A,1,1,MULTIPLY)
SET ATR = LOOP(B,TR(),0,0,ADD)/A
SET ATR14 = IF(A=14,ATR,0)
SET ST1 = (HIGH + LOW)/2 + 3ATR14
SET ST2 = (HIGH + LOW)/2 - 3ATR14
SET MA1 = EMA(CLOSE,10)
SET MA2 = SMA(CLOSE,50)
SET R = RSI(CLOSE,10)
SET ST = IF(TREND(CLOSE)=UP,ST1,ST2)
CLOSE<MA2 AND CLOSE<ST AND MA1<ST AND TREND(ST)=DOWN AND R>30

2

Please verify your code once again some thing is wrong in LOOP, and you have not given any parameter/value for TR() true range