a subset of antecedent roles that includes participant roles in between the participant role expressed as subject and the participant role expressed as object. Example: in Jack broke the window with a hammer, the hammer is antecedent to the window in the breaking causal chain (Jack → hammer → window), and the window is expressed as object; and it is also subsequent to Jack in the breaking causal chain, and Jack is expressed as subject. (Section 6.1.2)