operator types: op-sequence

op-sequence:
    description:
        sequence operator
        a sequence of operators, of any type, chained together
        each operator is separated by a space character
        and is evaluated from the right, towards the left
        the input to any operator is a sequence, the output of any operator is also a sequence
        consequently any chain of operators also maps an input sequence to an output sequence
        there is some similarity of operator sequences with the pipe command | on the command line

    examples:
    see also: