The attached xlate gives the following output , strips off pid and MRG  segments from an A47 mesage. I do not understand why  Thanks in advance for any help.
MESSAGE 1
0(0).MSH(0)  :  >|^~&|PARAGON|001|CLOVERLEAF||20180220135704.797||ADT^A34|2018022011364156|P|2.4<
0(0).EVN(0)  :  >|A34|20180220135703.817|||apryor<