Help needed on temporal expressions with detach

Hi everyone

     I am having trouble in writing a temporal expression using detach construct in e langauge. Any help is greatly appreciated.

    There are two events A and B in my environment. everytime B event happens A should have happened 0~3 clocks earlier.

    My temporal expression looks like below.

    expect @B => detach({@A;~[..3]})@clk else dut_error("B event error");

    In my simulation event B happens a total of 4 times. But the dut error is issued only once i.e. for the very first B event.

    I am wondering why the error is not issued for 2nd, 3rd and 4th events of B.

   I am using specman 10.2 version.

  - regards

    Jayachandra