context function 1: op-zip

op-zip:
    description:
        op-zip(seq) input-seq
        zip together a sequence of operators with a sequence of superpositions (given by input-seq)
        stops at the shorter of the two sequences
        NB: it is invoked slightly differently from the python version
        where it was: op-zip(seq, seq)

    examples:
        -- define some for-example operators:
        -- but keep it abstract for now:
        op1 (*) #=> |op1:> __ |__self>
        op2 (*) #=> |op2:> __ |__self>
        op3 (*) #=> |op3:> __ |__self>

        -- define the corresponding operator sequence:
        op |seq> => |op: op1> . |op: op2> . |op: op3>

        -- define a for-example sequence, again, just something abstract:
        the |input seq> => |a> . |b> . |c> . |d> . |e>

        -- now apply it:
        op-zip(op |seq>) the |input seq>
            |op1: a> . |op2: b> . |op3: c>

    see also:
        numbers-to-words.sw3