SIGNATURE ISeqSort[data]

-- functions related to sorting of sequences--

-- Parameter
SORT data

IMPORT  ISeq[data] ONLY iseq

FUN merge: (data**data->bool)->iseq[data]**iseq[data]->iseq[data] 
           -- merge (<) (s1, s2)
           -- merges two sequences s1 and s2  with respect to <
           -- provided that s1 and s2 are sorted with respect to <
           -- the result of merge is sorted too.